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Images: Emeralda Marsh Conservation Area

Saturday, February 16

From my first trip of the year to the wildlife drive at Emeralda Marsh Conservation area, near Eustis, last Saturday.

The male (red stripe extending back from the base of the bill; females lack this) of a pair of pileated woodpeckers that were courting and canoodling on the phone poles along Emeralda Island Rd.

The male (red stripe extending back from the base of the bill; females lack this) of a pair of pileated woodpeckers that were courting and canoodling on the phone poles along Emeralda Island Rd.

Several purple gallinules were active on the spatterdock beds along the edge of Lake Griffin.

Several purple gallinules were active on the spatterdock beds along the edge of Lake Griffin.

Mixed-species flocks of passerines were abundant and active in the hammocks along the wildlife drive and int the mixed habitat of the marshes and successional wetlands.  Lots of blue-gray gnatcatchers.

Mixed-species flocks of passerines were abundant and active in the hammocks along the wildlife drive and in the mixed habitat of the marshes and successional wetlands. Lots of blue-gray gnatcatchers.

Ruby-crowned kinglets were nearly as abundant as the gnatcathers.  I saw the ruby crown a couple of times, briefly.

Ruby-crowned kinglets were nearly as abundant as the gnatcathers. I saw the ruby crown a couple of times, briefly.

This marsh wren was working a clump of dead cattails right by the road on the T-J section of the wildlife drive.  Though he came within 10' of me, he never came completely out in the open for a profile shot.

This marsh wren was working a clump of dead cattails right by the road on the T-J section of the wildlife drive. Though he came within 10′ of me, he never came completely out in the open for a profile shot.

Swamp sparrows were abundant in the wet fields and marshes.   I saw only one savannah sparrow all day though.  Strange.

Swamp sparrows were abundant in the wet fields and marshes. I saw only one savannah sparrow all day though. Strange.

Palms were the most abundant warblers.  Others included yellow-rumps, common yellowthroats, and an orange-crowned warbler.

Palms were the most abundant warblers. Others included yellow-rumps, common yellowthroats, and an orange-crowned warbler. This is a very dull western palm warbler.

A brighter western palm warbler, starting to show a bit of breeding plumage in his rusty cap.

A brighter western palm warbler, starting to show a bit of breeding plumage in his rusty cap.

Blue-gray gnatcatcher

Blue-gray gnatcatcher

Orange-crowned warbler

Orange-crowned warbler

Female common yellowthroat

Female common yellowthroat

Not many aquatic birds were present, aside from fair numbers of coots and moorhens.  Only a handful of egrets and herons, and a few white and glossy ibis, like this one. I saw one limpkin, heard one sora.

Not many aquatic birds were present, aside from fair numbers of coots and moorhens. Only a handful of egrets and herons, and a few white and glossy ibis, like this one. I saw one limpkin, heard one sora.

Swamp sparrows were thick throughout.

Swamp sparrows were thick throughout.

Swamp sparrow

Swamp sparrow

The serpentine flow-way.  Even when the marshes and wetlands are a bit slow, always a beautiful drive.

The serpentine flow-way. Even when the marshes and wetlands are a bit slow, always a beautiful drive.

Image Gallery: Northern Bobwhite

January 6, 2015

Yesterday while searching for a pair of great horned owls I had seen recently on a dead end road near Heart Island Conservation Area, I saw a covey of a half-dozen or so northern bobwhite scurry across the road and begin picking their way up the roadside towards me.  I parked and waited.  For about 5 minutes I was able to watch and photograph these beautiful little fowl as they worked past me, only mildly wary of my presence.

My first shot was of this male that cautiously worked his way up the road  margin towards me.  He was clearly aware of my presence, but didn't seem overly concerned about the blue Accord sitting in the road.

My first shot was of this male that cautiously worked his way up the road margin towards me. He was clearly aware of my presence, but didn’t seem overly concerned about the blue Accord sitting in the road.

NOBO_01052015-06_Camp Winona Road

The scurried dash of a northern bobwhite as it crosses open ground is charming.

The scurried dash of a northern bobwhite as it crosses open ground is charming.

The slightly raised crest indicates a bit of concern.

The slightly raised crest indicates a bit of concern.

Still, this male sat in the open watching me for a few seconds.

Still, this male sat in the open watching me for a few seconds.

At some point, something mildly spooked this male and he hunkered down, no more than 20' or so away from me.  Didn't try to run away though; just sat there for a minute or two watching me.  I would never have spotted this bird if I hadn't seen it before it froze.

At some point, something mildly spooked this male and he hunkered down, no more than 20′ or so away from me. Didn’t try to run away though; just sat there for a minute or two watching me. I would never have spotted this bird if I hadn’t seen it before it froze.

Whatever the cause for alarm, he got over it fairly quickly and resumed activity.

Whatever the cause for alarm, he got over it fairly quickly and resumed activity.

Most of the covey remained  deeper in the sparse ground cover of the sandhills habitat.

Most of the covey remained deeper in the sparse ground cover of the sandhills habitat.

Incredible patterning on the  plumage of these birds.

Incredible patterning on the plumage of these birds.

Females can be distinguished from males by their yellowish heads.

Females can be distinguished from males by their yellowish heads.

NOBO_01052015-44_Camp Winona Road

 

 

Image Gallery: Okefenokee Swamp

 January 3, 2015

My somewhat serious resolution for the upcoming year is to increase the frequency of Volusia Naturalist posts.  To that end, I’m initiating the year with a new type of post – an image gallery.  For those times when I don’t have much to say, but want to share some photos of my adventures.

The photos in this set were taken over several days just before the new year.  All of the photos are hyperlinked to larger versions.  We spent most of our time in the Fargo area, at Stephen Foster State Park, with one afternoon trip to the east side of the Okefenokee at the Suwannee Canal Recreation Area, near Folkston.

A gray morning in the Okefenokee Swamp.  This is in Stephen Foster State Park, on the west side of the Okefenokee

A gray morning in the Okefenokee Swamp. This is in Stephen Foster State Park, on the west side of the Okefenokee.

The habitat surrounding the swamp is overwhelmingly dedicated to 20-year rotation timber farming.   This includes a significant acreage in Okefenokee NWR.  This is a tract of young slash pines that have been thinned and burned.

The habitat surrounding the swamp is overwhelmingly dedicated to 20-year rotation timber farming. This includes a significant acreage in Okefenokee NWR. This is a tract of young slash pines that have been thinned and burned. The profuse pale fuzzballs are seed heads of Pityopsis graminifolia.

This Google Earth image shows part of the entry road through Okefenokee National Wildlife Refuge (177).  The Suwannee river near its origin in the Okefenokee is above the road.  Notice that nearly all of the habitat that isn't wetland is covered by plots of timber at various stages of the harvest cycle.

This Google Earth image shows part of the entry road through Okefenokee National Wildlife Refuge (177), leading to Stephen Foster State Park on the western side of the refuge. The Suwannee river near its origin in the Okefenokee is visible above the road. The long straight line in the NE quadrant is the Suwannee River Sill, a several-mile long levee built in the 50’s to control outflow of water from the swamp into the Suwannee. This was an attempt to reduce fire frequency in the swamp during dry years by keeping more water in it. It was a failure. Notice that nearly all of the habitat that isn’t wetland is covered by plots of timber at various stages of the harvest cycle.

Alligators were out  basking on this gray day.  These beasts are in the canal paralleling the Suwannee River Sill.

Alligators were out basking on this gray day. These beasts are in the canal paralleling the Suwannee River Sill.

Great blue heron in the swamp.  Notice the fire-scarred trunks in the background; many of the plant communities in the swamp are fire-maintained.

Great blue heron in the swamp. Notice the fire-scarred trunks in the background; many of the plant communities in the swamp are fire-maintained.

The canal leading from the boat basin in Stephen Foster State Park to the Billy's Lake section of the middle fork of the Suwannee River.

The canal leading from the boat basin in Stephen Foster State Park to the Billy’s Lake section of the middle fork of the Suwannee River.

White-tailed deer were common and tame around the cabins at Stephen Foster State Park.

White-tailed deer were common and tame around the cabins at Stephen Foster State Park.

Red-shouldered hawks were abundant, many hunting the the grassy shoulders of the entry road.

Red-shouldered hawks were abundant, many hunting the the grassy shoulders of the entry road.

Sweetgum

Sweetgum

There were only a few hours of decent sun, on Tuesday afternoon, during the 3 days we were there.  This longleaf pine forest with cane understory is from the Suwannee Canal Recreation Area, on the east side of Okefenokee.

There were only a few hours of decent sun, on Tuesday afternoon, during the 3 days we were there. This pine forest with cane understory is from the Suwannee Canal Recreation Area, on the east side of Okefenokee.

Longleaf pine forest

From the Swamp Wildlife Drive in the Suwannee Canal Area.

A magnificent 3/4 mile boardwalk into Chesser Prairie are of the Okefenokee provides stunning views of this landscape still showing the effects of the 2011 Honey Prairie fire, which was allowed to burn.  Charred posts from a previous boardwalk are still present.

A magnificent 3/4 mile boardwalk into the Chesser Prairie area of the Okefenokee provides stunning views of this landscape still showing the effects of the 2011 Honey Prairie fire, which was allowed to burn. Charred posts from a previous boardwalk are still present.

Chesser Prairie, from the boardwalk.

Chesser Prairie, from the boardwalk.

Eastern phoebe from Chesser Island.

Eastern phoebe from Chesser Island.

Way too distant shot of a male northern harrier, from the boardwalk.  I don't see male harriers often, though females and immatures are common in winter in Florida.

Way too distant shot of a male northern harrier, from the boardwalk. I don’t see male harriers often, though females and immatures are common in winter in Florida.

Pig frog?  Active in the last week of December.   Ranids in Pennsylvania can only dream about that shit.

Pig frog? Active in the last week of December. Ranids in Pennsylvania can only dream about that shit.

Interesting assemblage of insects in the unwet portion of a water lily leaf.  There's a little water strider (Gerridae) in the notch, a small fly (Ceratopogonidae?) above it, and a "herd" of what look like some kind of leafhopper or planthopper nymphs.

Interesting assemblage of insects in the unwet portion of a water lily leaf. There’s a little water strider (Gerridae) in the notch, a small fly (Ceratopogonidae?) above it, and a “herd” of what look like some kind of leafhopper or planthopper nymphs. You have to click and see this at maximum resolution to see any detail in these tiny insects.

The diversity of fungal structures in this rotting branch was impressive.  I have no idea how many species of fungi are visible here.

The diversity of fungal structures in this rotting branch was impressive. I have no idea how many species of fungi are visible here.

Swamp doghobble, Eubotrys racemosa.  These are young flowering spikes that will bloom sometime in early spring.

Swamp doghobble, Eubotrys racemosa. These are young flowering spikes that will bloom sometime in early spring.

The last afternoon we were there produced the best light of the trip.  This shot of the Okefenokee from the boardwalk at Stephen Foster State Park was taken in late afternoon, as the window of sunshine was getting ready to close.

The last afternoon we were there produced the best light of the trip. This shot of the Okefenokee from the boardwalk at Stephen Foster State Park was taken in late afternoon, as the window of sunshine was getting ready to close.

Golden afternoon light can make any shot look decent, but with this kind of view, it's like taking candy from a baby. Which I've never done.

Golden afternoon light can make any shot look decent, but with this kind of view, it’s like taking candy from a baby. Which I’ve never done.

Peucetia cocoon_11012014-11_L George CA_1

Cold-blooded mothers

 

Peucetia viridan_11032014-03_620 COC

December 13, 2014

The great artist Haddaway asked “What is love?”; neither the Butabi brothers  nor I have come up with a satisfactory answer to that question, but if love is judged by actions, then it is much more widespread among animals than is commonly thought .  

I hate the term “cold-blooded” as a descriptor of the thermoregulatory syndrome shown by the majority of animals on the planet, but as a literary device it is quite useful.  Cold-blooded as a trope hints at an emotionless, detached demeanor, something that seems a world away from the values associated with motherhood.   Some of my recent and less recent experiences with cold-blooded mothers suggest the opposite.

A female lynx spider from mid-August, still fattening up in preparation for producing her cocoon.

A female lynx spider from mid-August, still fattening up in preparation for producing her cocoon.

Last summer I became entranced with the beauty and behaviors of lynx spiders.  Peucetia viridans is one of the first spiders I learned to identify when I moved to Florida (thanks, Craig), and I’ve been aware since then that they are common, widely distributed spiders.   But until I began looking for them with more conviction recently, I had no idea of their true abundance.   As spider expert Jack Koerner discovered independently, their prowess as predators is prodigious.  Not only will they tackle a diverse array of prey, many far exceeding their own body mass, they are also ridiculously abundant in some habitats.   As I learned more about them, I began to anticipate the appearance of cocoons and the subsequent maternal behaviors of the females.  Jack  assured me that they would begin appearing in late September-early October, and he was spot on.  I saw my first female guarding her cocoon on October 9, in the Riverside Island tract of Ocala National Forest.  After that first sighting, I started seeing them frequently, most often in the head-high inflorescences of dogfennel, Eupatorium capillifolium.  On November 1, I found a cluster of 4 females guarding cocoons in a patch of dogfennel at Lake George Conservation Area, and by some coincidence one of them came home with me.  I placed her with her cocoon and the top of her home plant on an old tripod, put it on my glassed-in patio, and began waiting.

The first cocoon I saw this fall, October 9, in Ocala National Forest

The first cocoon I saw this fall, October 9, in Ocala National Forest

The lynx mother I adopted, on her first day in the patio.  Notice that she is missing her left front leg.

The lynx mother I adopted, on her first day in the patio. Notice that she is missing her left front leg.

At first I wondered if all of the disturbance, combined with the rather profound change in surroundings (a sunlit successional opening in the scrub to a patio in a suburban subdivision) might cause her to abandon her nest.  But I trusted in her instincts, and sure enough, she never moved from her perch astride her cocoon.  

A couple of weeks into my wait, I began worrying that the thermal environment I had moved her to would be too cool to allow her eggs to develop at a normal rate.   The microhabitat where she had built her nest had direct exposure to the sun for at least a few hours a day; that heat boost must speed up embryological processes.  I hoped that the benefits of the sheltered patio might compensate in part for her loss of sun – it probably buffered the temperature extremes she would be exposed to in the open.  Perhaps the several hours each night she enjoyed temperatures above those of her natural environment would accelerate the development of her babies somewhat.   On November 14, while at Lake George Conservation Area, I visited her home patch to check out the progress of the other females from her cluster.  They were all still there; none had hatchlings yet.  It was while trying to photograph one under field conditions that I felt a little better about taking my female home; the wind was blowing at about 20mph, air temperature was in the 50’s, and it felt damned cold to me.  Further, the females atop their dogfennels were being buffeted back and forth violently by the shifting winds, yet somehow managed to hang on despite what must have been a semi-torpid state.   If they were bullriders, they would have all earned eights.  It took me about 10 minutes to take even a handful of photos, despite trying to brace and stabilize the dogfennel plants as best I could.  

It took me forever to get even one decent image of this mother lynx guarding her cocoon at Lake George Conservation Area.  She was being whipped around in every direction by the buffeting winds.

It took me forever to get even one decent image of this mother lynx guarding her cocoon at Lake George Conservation Area. She was being whipped around in every direction by the buffeting winds.

So at home I maintained my vigil, checking every day for the appearance of hatchlings, not even sure exactly what they would look like.  Would they be little emerald-green replicas of their mother?  

The red widow, Latrodectus bishopi, an endemic of scrub and an augur of good tidings.

The red widow, Latrodectus bishopi, an endemic of scrub and an augur of good tidings.

On November 30, John Serrao and I did the Ultimate Ocala Loop © looking for whatever animal, vegetable or mineral coolness we could scrounge up.  John had a focal animal for the day; he wanted to find a red widow, and that seemed like a cool goal to me, so we stopped on a couple of occasions in palmetto-studded early scrub so John could scour the scrub for spiders.   I was astounded when I saw him walking up the road with a palmetto frond, grinning like a hyena.  He’d found his widow.  I should have seen that as the grand spider omen it was.   When we got back to my house, we found that my lynx babies had hatched overnight or early that morning.  Big day for the spiders.

Mom with her litter soon on the day of hatching.

Mom with her litter soon after hatching.

Peucetia babies_11292014-11_620 COC

For the next two weeks, I had the awesome privilege of watching a master mother at work.   On the day I found her newly-hatched babies, I put momma lynx and her tripod-mounted home plant in my backyard garden, in a spot where they would receive at least several hours of direct sun exposure each day.  I didn’t really know how long her maternal devotion would last. 

Peucetia babies_11292014-07_620 COC

The spiderling just below the center of the frame is in the process of shedding its first skin.

The spiderling just below the center of the frame is in the process of shedding its first skin.

Newborn lynx spiderlings

Newborn lynx spiderlings

 For the first several hours after hatching, her entire brood of 40 or so dapper little spiderlings (mostly orange, not green!) remained within a couple of cm of the cocoon, with mom lurking either directly over them or nearby.  Any movement of the dogfennel head or activity near the cocoon would bring her rushing over and posting up in an aggressive stance.    I took a bunch of photos, and didn’t realize until I processed the images that some of the spiderlings were already shedding their exoskeletons for the first time.

Peucetia babies_12022014-06_620 COC

That’s when I thought of the other cold-blooded mother I’ve had some experience with. Pigmy rattlesnakes.  And I began to make comparisons.    Pigmy rattlesnake mothers stay with their litter of 2-12 baby rattlesnakes for several days after they give birth to them (most pit vipers give birth to living young rather than laying eggs), which was quite a revelation to me when we were doing pigmy rattlesnake studies back in the 90’s.   Not only do they stay near them, they actively defend them against some predators (such as other snakes).   Unlike mother lynxes, though, we never saw any sign of aggressive defense by mothers towards big stinking primates.  The response of both mother and baby rattlesnakes to the approach of hulking sweaty bipeds was usually to retreat to cover in a fairly leisurely fashion.   The mothers were simply choosing the battles they could win; mothers kept in captivity with their young did show an aggressive approach towards a predatory snake (black racer) that was tethered and moved towards the female and her young. (No racers were harmed in the process of provoking these pigmy moms!)

Nearly all pitvipers, and many other snakes, give birth to living young.  This is a pigmy rattlesnake birth.

Nearly all pitvipers, and many other snakes, give birth to living young. This is a pigmy rattlesnake birth.

Mother pigmy attending her litter.

Mother pigmy attending her litter.

Pigmy rattlesnake with her litter

Pigmy rattlesnake with her litter

Mother pigmy rattlesnakes maintain their maternal attendance until their babies have shed their natal skin; as soon as they do that, 1-4 days after birth, the kids disperse in all directions, and their association with their mother is over forever.  Oh, I suppose they might bump into each other at some point during their subsequent lives, but we found no evidence suggesting the kids periodically return to visit their mother.  Or even call.  

Once pigmy rattlesnake neonates shed their skin for the first time, they are on their own.

Once pigmy rattlesnake neonates shed their skin for the first time, they are on their own.

So based on my experience with pigmy motherhood, I thought that perhaps lynx mothers were similar; soon after they hatched and shed, the babies would disperse, and mom would do whatever mother lynxes with empty-nest syndrome do.  Which is mostly die.  Lynx spiders, unlike pigmy rattlesnakes, reproduce only once, and then die.  

I was hoping to actually photograph some baby lynxes ballooning away.  Didn't happen.

I was hoping to actually photograph some baby lynxes ballooning away. Didn’t happen.

Peucetia babies_11302014-18_620 COC

Around noon the day after the lynxes hatched, I checked out the dogfennel briefly, and didn’t see mom or any spiderlings near the cocoon.  I concluded, prematurely as it turns out, that the babies had all ballooned away and the mother had departed.   Many young spiderlings, when ready to disperse from their birth site, climb to the top of a plant when there is a breeze blowing, stick their butts up in the wind and begin releasing silk.  When enough silk is out, they release their grip and drift away on their silken balloon.  I was pretty pleased at the prospect that all those spiderlings were now safely ensconced in little lynxy hidey-holes scattered around my garden, and that I might see some of them the following spring and follow their growth and maturation.

Peucetia babies_11302014-00_620 COC

The next day I decided to do a more thorough search for a lingering baby or two and was surprised and delighted to find the female back atop the plant.  As I looked carefully around the dogfennel inflorescence, I found 10-15 babies scattered around the many nooks and crannies of the dogfennel head, now covered with seeds and their pappuses (pappi?).  Looking very much like little spiders.  Coincidence, Harry Tiebout?   It didn’t take long for mom to key in on whatever part of the plant I was focusing on and come rushing over.  The next day she was surrounded by 15-20 of her babies, clustered loosely around her again.

 Mom with her brood 3 days after hatching

Mom with her brood 3 days after hatching

Peucetia babies_12022014-14_620 COC

And now here it is, two weeks after birth, and mom is still hanging on.  She’s missing a leg, has a patch of white fungus growing on one of her legs (immune system shutting down?), and is moving at an arthritic pace even at mid-day temperatures.  Every morning for the last several days I’ve gone out to check on her, expecting to find her dead.  Some mornings it’s not easy to tell at first.  I can gently prod her and move her legs, and in her early-morning torpid state, it’s hard to tell if there’s any voluntary movement at all.  But by mid-morning, after a nice spot of sun, she’s still endeavoring to persevere.  Perhaps I should craft her a tiny stove-pipe hat and declare her civilized.  

Mom on December 9, down to only a few remaining babies still at home.  Still defensive, but slowing.

Mom on December 9, down to only a few remaining babies still at home. Still defensive, but slowing.

Peucetia babies_12092014-20_620 COC

Sticking close to mom.

Sticking close to mom.

Catching the last bit of sun in the afternoon.  Wonder if she feels as arthritic as she looks?

Catching the last bit of sun in the afternoon. Wonder if she feels as arthritic as she looks?

Yesterday, I thoroughly inspected the plant with a visor magnifier, and found only one baby remaining.  On mom. For whatever it’s worth, a more devoted and persistent mother than the more “advanced” pigmy rattlesnake.  The baby lynx stayed on his mother’s emaciated abdomen for several minutes while I photographed them, and then rappelled on a silken dragline to a seed cluster below.  Mom moved achingly slowly to the top of the plant to bask.  Would this be her last sunset?

One more morning.

One more morning.

Peucetia viridan_12122014-21_620 COC

Ravaged by starvation, fungus, and who knows what other maladies, she soldiers on.

Hanging with mom.

Hanging with mom.

Just 15 minutes ago, I could find no baby lynxes other than one tiny mummified little corpse. But mom is still there.

Yesterday afternoon.   No more than a few days left for her at most.  I'll miss her.

Yesterday afternoon. No more than a few days left for her at most. I’ll miss her.

Does a mother pigmy rattlesnake or lynx spider love her babies?

What is love?

Postscript, December 21:

She was tougher than I gave her credit for.  She was dead this morning, over a week after the last of her offspring had dispersed.

Lynx mom RIP_12212014-10_620 COC

 References:

Greene, H. W., May, P. G., Hardy, D. L., Sciturro, J. M., & Farrell, T. M. (2002). Parental behavior by vipers. Biology of the Vipers, 179-205. 

Urocyon cinereoa_09212014-47_Ocala NF FR69

Caniphilia

 October 18, 2014

I don’t think it’s really necessary to coin this term; the love of dogs is a fundamental human condition.  I wouldn’t trust a man who dislikes dogs as far as I could throw him.   Such an inability to form a connection with these magnificent animals with whom we share a long coevolutionary history indicates a very basic flaw in character and humanity.  To any dog-haters who might happen to read this, I have this advice.  Seek treatment for your affliction.  Try to make yourself a better human being.

Dogs are the original GMO, or genetically modified organism.  As William Sanderson’s wonderful character in Blade Runner, B.F. Sebastian said, speaking of his robotic humanoid toys, “They’re my friends.  I made them.”  Dogs are our friends.  We made them.

J.F. Sebastian, with Pris and one of his friends.

J.F. Sebastian, with Pris and one of his friends.

In contrast to modern GMO’s, which are largely  created by copying and pasting specific genes from one organism to another, dogs were built the old-fashioned way, over thousands of generations of artificial selection.   Although the mechanism by which dogs first became domesticated is not entirely clear, the process began at least 15,000 years ago, and perhaps far more.   DNA sequencing evidence strongly suggests that wolves were the progenitors of the domestic dog, and the first steps towards domestication may have occurred when humans adopted wolf pups and socialized them to accept human companionship, or it may have been more of a “self-domestication” process in which some wolves began associating with humans for food, protection, and perhaps other benefits.   Since those earliest proto-dogs, selective breeding by humans (artificial selection) has produced an entirely new animal, recognized as a separate species from the gray wolf (though dogs and wolves readily hybridize, as do other members of the genus Canis, including coyotes).   

A recent paper in the journal Genetics (Wilkins et al. 2014) presents a fascinating story about the interaction between genes, embryological processes, and evolutionary change and how these processes have produced many of the differences seen between dogs and their canid ancestors.   Dogs, like many domesticated mammals, show a suite of traits that seem to commonly arise during domestication.   Aptly dubbed “domestication syndrome”, these traits include reduced fear and anxiety around humans (tameness), as well as physical traits like changes in color patterns, droopy ears and tails, reduced brain and skull size, and smaller teeth.   Why do all of those traits tend to occur together in domesticated animals, when it is primarily the tameness that is being selected for in their interactions with humans?

From Wilkins et al., 2014.

From Wilkins et al., 2014.

According to Wilkins et al., the phenomenon of tameness is one of many traits linked to a remarkable group of cells, found only in vertebrates and their closest relatives (tunicates),  that are active in early embryological development.  These cells, called neural crest cells, originally form and differentiate as part of the developing nervous system during the process called neurulation.  But rather than stay with the central nervous system to form the brain and spinal cord, as most of the cells formed during neurulation do, neural crest cells are wanderers.  They break away from the developing spinal cord and travel throughout the body to take up residence in a wide variety of developing tissues and organs, and differentiate into a dizzying diversity of tissues and organs.   Some move into the skin, where they form the pigment-producing cells called melanocytes.  Others are involved in formation of cartilages in the ears, while other neural crest cells form one of the types of cells that build teeth, the odontoblasts.  Others contribute to bones of the skull, while yet other neural crest cells become neurons and ganglia of the peripheral nervous system.  Most importantly with regard to domestication, neural crest cells are involved in development of the adrenal glands and other components of the sympathetic nervous system, which produces the so-called “flight or fight response” when vertebrates are placed in physically or emotionally challenging situations.  

According to the Wilkins et al. model, domestication first began genetically modifying dog ancestors by selectively favoring those individuals that showed reduced stress response around humans, due to a less intense “fight or flight response”.   These were individual wolves that had experienced reduced neural crest activity during development, and a somewhat underdeveloped adrenal gland/sympathetic nervous system response.  Such variability in genetically encoded traits is a prerequisite for natural or artificial selection to occur, and is widespread.

But because neural crest cells are involved in so many other developmental events, selection for reduced neural crest activity (“mild neurocristopathy”, as they called it) also resulted in evolution of other traits, including floppy ears and droopy tails (reduction in cartilage-producing tissues), color patterns (reduced melanocyte activity), smaller teeth (reduced odontoblast activity), and smaller skulls and brains.   Though only “tameness” was being directly favored by their association with humans, changes in physical traits transpired due to the selection for reduced neural crest cell activity.  This is, to me, a truly elegant hypothesis, which emphasizes the ease with which minor changes in developmental pathways can lead to major evolutionary changes in body form and function of the adult organism.  

Luna, indisputably the greatest dog who ever lived

Luna, indisputably the greatest dog who ever lived

Regardless of how dogs got to be dogs, the result is an animal with which we are inextricably linked in our evolutionary meanderings.  And it is completely natural to love them.   The only dog I’ve ever had that belonged only to me was a little mixed-breed husky mix named Luna, and I loved that dog in ways that I never knew were possible.  When I had her put to sleep in 2006, I was inconsolable for months.   I’m not ashamed to say that for weeks after she died, I would find myself at times sobbing uncontrollably over the loss.  I still get a little misty-eyed sometimes when I look at old pictures of her.  

If I saw mammals like this Sigmodon hispidus more often, I'd probably like them better. But I don't.

If I saw mammals like this Sigmodon hispidus more often, I’d probably like them better. But I don’t.

Truth be told, I’m actually not all that enamored of most mammals – they are largely nocturnal, not particularly colorful, and often difficult to observe, all traits in direct contrast to some of my truly favorite taxa such as birds, butterflies, odonates, and flowering plants.  But I make an exception for carnivores, and particularly canids.  Nothing excites me as much as seeing a wild dog.  Coyotes are absolutely enchanting animals.  God’s dog, as they have sometimes been called, are beautiful, wicked smart, adaptable, and at times quite mischievous, to put it mildly.

I had been living in Florida for over a decade before I saw my first coyote.  I still have a vivid memory of driving north on Lake Winona Road in 1991 or 1992,  through mixed sandhills, hammocks, and agricultural habitat and seeing a doglike animal crossing the road a couple hundred yards ahead of me.  As it reached the edge of the road, it paused broadside and looked directly at me for a few seconds before disappearing.  No more than a 15-second observation, if that, but I knew instantly it was a coyote.  The lope, the elegant profile, big ears – all screamed coyote.  I was entranced.  It took several years before I saw another, this one only briefly again as it darted across Dark Entry Road in Tiger Bay State Forest.  

In the last several years, though, I’ve been seeing coyotes much more regularly.  Maybe because I’m getting a little better at spotting them, maybe because they are increasing in numbers.  Probably some of both.  I sure hope at least the latter is true.   For one thing, more coyotes means fewer feral and free-ranging cats.   And that’s a good thing.  When human activity first begins modifying the ecological systems in a developing area, top predators are usually the first component to disappear.  It gives me a bit of hope to see them increasing on their own, despite widespread prejudice and wanton slaughter of these beautiful dogs.   Over 75,000 coyotes were killed in 2013 alone by the USDA’s Wildlife Services, along with many other top predators. (Thanks to Mia McPherson and her wonderful blog On The Wing Photography for that disturbing statistic.)  Yet they continue to prosper.

Canis latrans_092511_6_Lake County

I’m still waiting for my first decent photo opportunity with coyotes.  In 2011, I watched one circling a herd of cattle, including a small calf, looking very much like a border collie working a flock, from State Road 42 in Lake County.  For a minute or two, the coyote stayed in view, frequently veering back and forth as it scoped out the big slobbering bovines.   Quite distant, but my first coyote photos.  In 2012, I was driving through Heart Island Conservation Area near mid-day in August, and saw a pair of half-grown coyote pups trotting down Deep Creek Road in front of me, occasionally slowing to give me  a sidelong glance.    More recently, I had direct eye contact for a fleeting but electrifying moment as I drove by one in Ocala National Forest, on SR19 just south of Silver Glen Springs.  He had crossed the road in front of me and paused briefly to look back from the dense thicket perhaps 50 feet away.  This year I’ve seen single coyotes a couple of times at Lake George Conservation Area, and a month or so ago crossing Rima Ridge Road in Tiger Bay State Forest, near the Bennett’s Field primitive campground.  But I still haven’t been close enough to one in decent light to get true coyote photos (as opposed to photos with a coyote somewhere in them).   But I always assumed that the first wild canid I photographed in Florida would be a coyote.

Stalking coyote.

Stalking coyote.

This one might be doable, he's thinking.

This one might be doable, he’s thinking.

Coyote pups at Heart Island Conservation Area.

Coyote pups at Heart Island Conservation Area.

In Tiger Bay State Forest

In Tiger Bay State Forest

How wrong I was.  On September 21, I was cruising north on Paisley Road through Ocala National Forest, perhaps a half-hour after sunrise.  As I rounded a bend near a big seasonal wetland called Mud Lake, I saw two quadrupeds in the road several hundred yards away.  My first thought was coyotes, but they were small and delicate looking. Gray foxes! I’ve probably seen gray foxes in Florida less than 5 times in the 30+ years I’ve lived here.  Knowing with absolute certainty that they would be gone as soon as I slowed down, I pulled sharply to the right and grabbed my camera with the 150-500 Sigma zoom and slowly moved it up and onto the beanbag on my car window. And of course both foxes had darted into the thick patch of Bidens (alba, CB!) at the road’s edge. But after a moment one came back out. She trotted back across the road, turned around, and then spent a half-minute or so dawdling in the road. I took a distant shot, but it would be marginal at best. Still, a gray fox.  Starting the engine and attempting to slowly stalk her in the car seemed a pretty vain course of action.

Paisey Road, Ocala National Forest

Paisley Road, Ocala National Forest

My first view of the gray foxes. Hard crop.

My first view of the gray foxes. Hard crop.

Then I recalled a conversation I had recently had with my friend John Serrao, when we had been on one of our field jaunts. I think we had seen a bobcat or a coyote briefly, and John told me of several experiences he had with predators while living in in Pennsylvania. He told me had been able to call in a variety of predators by making squeaky noises with his lips, much like the squeaky noises birders sometimes make to attract dicky birds. He once had a weasel walk across his shoe, he told me, as he stood absolutely still and made the squeaking noises. Very soon after that conversation, I searched on-line and found several .mp3 files of rodent distress calls, which I added to my Ipod library, thinking I’d probably never use them.

Urocyon cinereoa_09212014-37_Ocala NF FR69

Urocyon cinereoa_09212014-38_Ocala NF FR69

Urocyon cinereoa_09212014-23_Ocala NF FR69

Maintaining contact with her mate, out of view in the roadside vegetation.

But in fact I did use them. As the fox frolicked in the road far away from me, I played one of the tracks titled “Squealy”, a series of high-pitched shrieks from some rodent or hare, through my car stereo. The effect on the vixen was immediate, and thrilling to me. First she looked directly at me, ears erect, clearly focusing on the sounds. And then she came closer.  And closer.  And closer.  She criss-crossed the road repeatedly, veering from one margin to the other, approaching me in a series of diagonal trots, all the while focused on me, trying to fire off frames without making any obvious movement. On several occasions she stopped and faced towards the thick vegetation beside the road that her running mate had gone into – I suspect he was paralleling her as she neared me, but staying out of sight in the vegetation. Once or twice she stopped, squatted, and apparently peed briefly.  Mostly as she covered the substantial distance between us she was in the shade, but on a couple of occasions she passed through pillars of low-angle sunlight streaming in through small gaps in the roadside vegetation. The combination of the exquisite delicate beauty of the vixen and the rich, warm early-morning light nearly made me delirious with joy. When she made her final veer and crossed the road no more than 50’ in front of me disappearing into the brush, I was as high as a kite on adrenaline and whatnot. 

In the light pillar.

In the light pillar.

And still she came.

And still she came.

Girl's got to pee when a girl's got to pee.

Girl’s got to pee when a girl’s got to pee.

A few moments after she had disappeared and I began to come down a bit from my reverential high, I realized I had photographed the entire sequence with the OS (optical stabilization, a vibration-reduction system to reduce camera movement and improve image sharpness) on my big telephoto lens OFF. Momentary panic followed as I envisioned all of the shots being uselessly blurred due to the slow shutter speeds I was forced to use in the early morning light. A couple of minutes spent “chimping” the hundred or so images I had taken on the camera’s display calmed my fear a bit – perhaps not as sharp as they could have been, but at least a couple were acceptable. 

Urocyon cinereoa_09212014-53_Ocala NF FR69

Still checking the road margins for the shier male.

Back and forth she came.

Back and forth she came.

Urocyon cinereoa_09212014-59_Ocala NF FR69

The final veer. The eye contact was amazing.

The final veer. The eye contact was amazing.

Last usable shot in the sequence.

Last usable shot in the sequence.

It was a once-in-a-lifetime privilege for me to watch and photograph this charming wild dog, if only for a few minutes. For the life of me I can’t understand the mindset of those who wish to kill these and other top predators on general principle. 

Coyotes are next.  It can’t happen too soon.

Acknowledgements:  Thanks to Gene Spears, or Gene Gene the Dancing Machine as he was known in grad school days, for turning me on to the Wilkins et al. paper.

References:

Wilkins AS, Wrangham, RW and Fitch WT (2014) The “Domestication Syndrome” in Mammals: A Unified Explanation Based on Neural Crest Cell Behavior and Genetics. Genetics 197(3):795-808.

 

 

Peucetia viridan_09132014-19_L George CA

Lovely lethal lynxes

Peucetia viridan_08152014-12_Tiger Bay RR

September 28, 2014

I’ve always been kind of partial to spiders, though at the same time just a bit intimidated by them.  Although the vast majority of North American spiders are of no significant threat to people, the idea of catching a big orb-weaver in the face when I’m in the field still creeps me out if I think about it.  My real introduction to spider biology at anything other than an extremely superficial level came when I first began grad school at UF, and became friends with an arachnophile, Craig Hieber.  Much of what I know about Florida spiders I learned from Craig, and though I can’t say for certain that he was the one who first introduced me to the green lynx spider, I think there’s a pretty good chance he did.  UF Zoology at that time was a hotbed of spider research – faculty members John Reiskind and John Anderson both did research on spiders, and mentored a number of grad students doing their master’s or doctoral research.  Even H. Jane Brockmann, always one of my favorites among the faculty (“do you people say bloody over here?”), got in on the spider action, and her student Linda Fink produced some splendid papers on reproduction and defense by green lynx spiders as an outcome of her master’s thesis.

My friend Craig Hieber (Charlie White in back).

My friend Craig Hieber (Charlie White in back).

Green lynx spiders, Peucetia viridans, are one of the most common Florida spider species.  They prompt the greatest number of requests for identification by the arthropod experts at the Florida State Collection of Arthropods of any spider species in Florida.  Commonly found in ruderal (disturbed) habitats and edges, particularly among flowers in the late summer and fall, I’ve known about their abundance for some time.  When I first moved to my current home in DeLand six years ago, the gardens I planted were loaded with lynxes.  More recently, since I’ve begun spending a lot of my field time ode-cruising, I’ve been struck again how incredibly common they are.   Green lynxes can be pretty cryptic as they spend large amounts of time motionless amidst an inflorescence waiting for some clueless victim to make the mistake of a lifetime, but once you’ve developed a search image, you can’t help noticing them.

Peucetia viridan_09132014-02_L George CA

A male lynx spider, identifiable by the extensions from his palps.

They are so abundant in some habitats, including agricultural fields, that they are an effective biological control agent against some agricultural pests, particularly the many species of noctuid moths that oviposit and feed as larvae on crop plants.  The good that lynxes do by reducing herbivory on crop plants is counteracted somewhat by the number of beneficial insects they consume along with the pests.  Bees, wasps, butterflies and skippers, syrphids and other types of flies… the list goes on and on. Lynx spiders seem to be very opportunistic predators who will take just about any type of insect prey that they can get their fangs on.

With geometrid moth prey

With geometrid moth prey

 

Honeybee prey

Honeybee prey

Tiphiid wasp (Myzinum sp.) prey

Tiphiid wasp (Myzinum sp.) prey

Stiletto fly (Therevidae, Penniverpa sp.)  prey

Stiletto fly (Therevidae, Penniverpa sp.) prey

Tiger moth (Halisidota sp) prey

Tiger moth (Halisidota sp) prey

Ladybeetle (Harmonia axyridis) prey

Ladybeetle (Harmonia axyridis) prey

Monarch caterpillar prey

Monarch caterpillar prey

Crabronid wasp prey

Crabronid wasp prey

And what lovely fangs (chelicerae) they have.  Members of the family containing the lynxes, the Oxyopidae, are distinguished by their relatively tall clypeum (the portion of the “face” between the eyes and the chelicerae) and elongate chelicerae.  Looking at a lynx spider head-on makes me think of an old, droopy-faced wizard.  The Oxyopidae is not a huge family – a bit over 400 species in 19 genera worldwide, in Florida they are represented by only a few species in two genera (Peucetia and Oxyopes).  I’ve never seen any of the Oxyopes species, but I’ve seen more lynxes than you can shake a snake hook at.  They are ubiquitous at this time of year.

The high clypeum, big chelicerae, spiny legs, and unusual eye arrangement are all characteristic of the Oxyopids.

The high clypeum, big chelicerae, spiny legs, and unusual eye arrangement are all characteristic of the Oxyopids.

Finding them isn’t hard.  I’ve seen them referred to in one source as “Inflorescence spiders”, and that is spot on.  If you want to find lynxes, look for them on the inflorescences of a variety of weedy plants, including many composites.   Because they are so cryptic, it helps to look for particular irregularities in flower clusters, like an out-of-place green lump in the midst of the flowers, or the translucent spiny legs projecting out from the flowers.  I’ve lost count of the number of times I’ve found lynx spiders lurking in the background when doing post-processing of photos of other flower visitors.  With their delicate green cephalothorax and abdomen, decorated by whitish chevrons in the larger females, and their nearly transparent multicolored spiny legs, there is nothing to confuse a lynx spider with.  

Early instar lynx on sunflower.

Early instar lynx on sunflower.

On purple thistle, Cirsium horridulum

On purple thistle, Cirsium horridulum

On goldenrod (Solidago sp)

On goldenrod (Solidago sp)

On Hyptis alata

On Hyptis alata

On Pluchea foetida

On Pluchea foetida

On Helenium amarum

On Helenium amarum

On redroot, Lachnanthes carolina, with potential victim

On redroot, Lachnanthes carolina, with potential victim

On pine lily, Lilium catesbaei

On pine lily, Lilium catesbaei

Though I’ve been seeing and appreciating lynxes for years, I was thrilled to recently photograph a male lynx for the first time. Males are slightly smaller than females, but as in most spiders, males are distinguishable from females by their modified pedipalps.  Pedipalps, or palps for short, are the pair of short leg-like appendages extending from the head, with which spiders manipulate  prey or other objects.  Palps are also intimately involved in mating behavior – they are the surrogate penises for males.   Prior to mating, male spiders spin a pad of silk and deposit semen on it and transfer the sperm to receptacles at the end of their palps.  Male spider palps are typically enlarged at the end, sometimes with syringe-like structures and extensions that aid in the process of inseminating the female.  I wonder if female spiders reluctant to mate sometimes give “palp jobs” to persistent males to cool them down?

A male lynx spider, showing the enlarged palps with hook-like extension

A male lynx spider, showing the enlarged palps with hook-like extension. You can click on this image (and most images on the blog) to see more detail in the palps.

Lynx spiders obtain their name from their hunting behavior.  They are ambushers and stalkers, using their acute vision to track and pounce on unwary prey.   I’ve never been lucky enough to see one making a kill, but I have on several occasions watched a hunting lynx make a quick dart towards pollinators approaching the flower they are sitting on.   Just yesterday I photographed one that had just seconds previously captured a small darkly-colored grass skipper; the lynx had her fangs embedded in the skipper, and it slowly unfurled and then recoiled it’s proboscis as the venom took hold.  At one point the struggling skipper forced the lynx to release her hold on the plant, and the spider and her skipper prey dangled from a few silk lines, spinning in the faint breeze until she regained her purchase.

Skipper prey

Skipper prey

Did someone say badass?  Lynx spiders seemingly know no fear.  They’ll take just about any prey they can inject their venom into, including some insects as large or larger than the spider.  Occasionally, however, the tables are turned and insects that could be taken as prey take the spider.  Many species of solitary wasps provision their nests with paralyzed spiders to feed their developing offspring, and lynx spiders are among the victims.

Leaf-footed bug (Leptoglossus phyllopus) prey

Leaf-footed bug (Leptoglossus phyllopus) prey

Antlion prey

Antlion prey

Dragonfly (Libellula sp) prey

Dragonfly (Libellula sp) prey

On a number of occasions, I’ve seen lynx spiders with prey being victimized by another arthropod colleague, though not with such drastic results as their interactions with spider wasps.   Lynx prey items are sometimes attacked by hemolymph-sucking ceratopogonid flies (midges) as the spider is sucking out the liquefied prey contents.   I don’t know whether the midges also attack the lynx, but they do parasitize other adult arthropods, such as dragonflies.

This leaf-footed bug (Leptoglossus phyllopus) being eaten by the spider is also hosting a big crowd of ceratopogonid flies sucking on the hemolymph.

This leaf-footed bug (Leptoglossus phyllopus) being eaten by the spider is also hosting a big crowd of ceratopogonid flies sucking on the hemolymph.

Do the midges parasitize the lynx as well?  Who knows?

Do the midges parasitize the lynx as well? Who knows?

 Aside from their general ferociousness and take-no-prisoners attitude, lynx spiders show a gentle side.  They are excellent mothers.  Linda Fink’s research while at the University of Florida revealed that females guard their egg cases (cocoons) for several weeks after they lay the eggs, and that this defensive behavior significantly increases survivorship of cocoons when compared to experimentally manipulated cocoons from which the female had been removed.  Ants seem to be the biggest threat; the female lynx will directly attack the ants, though on occasion they will chomp down on a leg and not release their grip even after death.  Linda observed lynx spiders in some instances sacrificing a leg (autotomy) to rid themselves of the dead hanger-on.   Their maternal devotion doesn’t protect the eggs from one other threat, though – parasitic mantidflies (Mantispidae) that lay their eggs in the spiders’ cocoons were equally common in both Linda’s control (mother remained) and experimental (mother removed) treatments.

The mantid fly Zeugomantispa minuta.

The mantidfly (Family Mantispidae, Order Neuroptera) Zeugomantispa minuta.

Linda even documented a new defensive behavior for lynxes while doing her research on maternal care – they spit venom in the direction of their enemy.   Although there is an entire family of spiders that specializes on spitting their gooey silk-containing venom cocktail on their prey to immobilize them (the Scytodidae), green lynx spiders are the only oxyopids known to defend themselves in this way.

A fat female who will soon produce an egg-filled cocoon

A fat female who will soon produce an egg-filled cocoon

If the standard defensive measures don’t work, lynx mothers will relocate their cocoon to another plant.  But they do so in a unique way; they don’t carry the cocoon to its new site, as some other spiders do, but instead reengineer its attachment.   They establish new suspensory silk lines anchoring the cocoon to the foliage of a nearby plant, and then cut the silk lines attaching it to its current host.  The cocoon swings over to its new site and the female then secures it with more silk. 

Lynx and beautyberry

Lynx and beautyberry

She stays with the developing eggs in the cocoon for several weeks until they hatch, sometimes refraining from feeding and starving herself in the process.  The cocoon can contain 25-600 eggs, averaging about 200.  Whether the female refrains from feeding or not, she will die sometime during the fall, and her early-instar offspring will overwinter, maturing and reproducing themselves about 300 days later. 

Baby lynx on Gaillardia

Baby lynx on Gaillardia

My next photographic goal – obtain a cocoon or two, with attending female, and keep them in captivity until the little dudes hatch.  Is there anything more adorable than a batch of a couple hundred little lynx spiderlings being doted on by a loving mother?  I doubt it.

References

Fink, L.S. 1986.  Costs and benefits of maternal behaviour in the green lynx spider (Oxyopidae, Peucetia viridans).  Animal Behaviour 34(4):  1051-1060.

Fink, L.S. 1987.  Green Lynx Spider Egg Sacs: Sources of Mortality and the Function of Female Guarding (Araneae, Oxyopidae).  Journal of Arachnology 15(2): 231-239.

 

 

Golden-winged skimmer, Libellula auripennis

Of orthops and odes

Conocephalini_08302014-01_Heart Island DC

September 20, 2014

I’m undergoing a seismic shift in my natural historizing, it seems.  Normally this time of year I’d be out in the field on any morning I can, frantically seeking migrant songbirds (and often failing).  Thus far this migration season, which began back in early August for me, I’ve spent virtually no time seriously birding.  I’ve been out several mornings with birds in mind, but when avian action was not readily forthcoming, I switched my focus to a more attainable target – insects and other spineless beasts.  Two reasons: I could find them, and I could photograph them.

Eastern amberwing, Perithemis tenera, on Carphephorus odoratissimus

Eastern amberwing, Perithemis tenera, on Carphephorus odoratissimus

I have this bizarre compulsion that taints everything I do when digging on the natural world – I have to take photographs of whatever I’m seeing, if at all possible.  It’s an affliction really, that impacts my ability to just chill the fuck out and groove on nature.   Close friends who come to visit me and sit on my porch and watch birds with me have remarked on this on numerous occasions.  Do you really need more photographs of northern cardinals?  Point taken.

Blue dasher, Pachydiplax longipennis

Blue dasher, Pachydiplax longipennis

Nonetheless, as some great sage (who I may be related to) once said, it is what it is.  One of the many benefits of teaching college is the extended vacations, which allow me to devote most of my energies to some goal I find hard to accomplish during the semester.  This past summer, my main goals were to increase my fluency in field botany and to learn to find, identify, and photograph dragonflies and damselflies, the odes of the title (a bug geek term for insects in the order Odonata).   In pursuit of odes, I’ve rediscovered my fascination with hexapods of all sorts; insects are so unendingly diverse and intriguing that one could spend a lifetime studying the natural history of insects in Volusia County and still only scratch the surface.  On the worst birding days, it’s very rare that you can’t find some interesting arthropods to ponder.

Twin-striped forceptail, Aphylla williamsoni

Twin-striped forceptail, Aphylla williamsoni

So odes have been a primary focus for me the last several months.  But photographing them requires getting fairly close, if one is using a typical macro lens in the range of 100-200mm focal length.   Plus, I do a lot of observation and photography from the car, which allows me to cover way more habitat than I ever could awheel.  (Is that a word? Afoot, awheel – why not?) Further, dragging my chair out of the backseat and getting self-mobile takes a couple of minutes, so even if the substrate is doable for me, getting out for every photo op just isn’t a workable strategy for me and those of my ilk.  Driving close enough to a perched dragonfly to get a reasonable image with my usual insect lens, a 150mm Sigma macro, is pretty tough to do.   Dragonflies can be pretty wary beasts. For several years I’ve tried sporadically to take “macro” photos of some larger inverts, like odes, with my main bird lens, a 150-500 Sigma.   But at the closest focus distances, I was having a lot of trouble consistently getting sharp images.   Sometimes razor, sometimes vaseline.

Eastern pondhawk, Erythemis simplicollis, with prey, on chalky bluestem

Eastern pondhawk, Erythemis simplicollis, with prey, on chalky bluestem

My breakthrough with odonate photography from the car came in August, when a female mud dauber began building a nest in the tracks of my sliding glass door, and I decided to try and photograph her.   She was too high for me to get decent shots with my standard macro, and the angle would be too steep if I shot from right underneath her anyway.   I remembered a 20-year old lens I had relegated to the photo gear graveyard soon after I went digital and got the big Sigma zoom.  The old lens was also a Sigma, a 400mm 5.6 lens that was the first refractive lens I used seriously for bird photography.  For a couple of decades I had wasted my time trying to do bird photography with one of the horrid old mirror lenses, which were cheap for their long focal lengths, but generally produced rather low-quality images.   A coincidental meeting at Lake Woodruff NWR with the great bird photographer Artie Morris, who I’d never heard of at the time, enlightened my world.  From a distance, I was blown away by the gigantic camouflaged 600mm lenses and Gitzo tripods he and his companion were toting (big-time big lens envy), so when we passed I chatted them up a bit.  When I showed Artie my mirror lens rig, he graciously avoided snorting in derision, and suggested I upgrade to a refracting 400 f 5.6.  He took a body with his 400 f5.6 Canon lens (his “toy lens”) from around his neck and allowed me to look through it.  I was sold, and bought the Sigma 400 soon after.

The immodest grasshopper, Melanoplus impudicus, eating flowers of Liatris tenuifolia

The immodest grasshopper, Melanoplus impudicus, eating flowers of Liatris tenuifolia

I used that lens for years when I did slide photography, and it was a splendid lens.  Incredibly slow 1st-generation autofocus, with no internal motor, but I never used that when I shot with a film body.   But it was renowned for its sharpness, and it was sold as a “Macro” lens.  Not really, but it would focus close enough to get to a 1:3 reproduction ratio, which is pretty decent for a lens with that much reach.  Perfectly suitable for larger insects.  So it occurred to me to drag that old relict out, set it up on a tripod with a soft-boxed flash, and focus on the dauber’s nest, waiting for her regular returns.  I was impressed again by the image quality, and the Sigma 400 became my lens of choice for insect photography from the car.  I doesn’t have any of the vibration reduction systems typical of long telephotos these days, so handholding it and getting critical sharpness are mutually exclusive.  I normally shoot from a beanbag on my car door when doing automotive photography, and that setup is rock solid.

Schistocerca damnifica, the mischievous bird grasshopper

Schistocerca damnifica, the mischievous bird grasshopper

So that’s how I shifted my focus from cruising for birds, which can be abysmally slow in the summer, to cruising for dragonflies, which is usually exactly the opposite.  Ode cruising, I call it.  And in the process, I began keying in on the other big arthropods that can be spotted and photographed while ode cruising.  As it turns out, the most commonly observable and shootable big insects I see are grasshoppers and katydids, of the order Orthoptera.  Orthops for short.

The olive-green swamp grasshopper, Paroxya clavuliger

The olive-green swamp grasshopper, Paroxya clavuliger

So these days, I get more excited about the idea of photographing orthops and odes more than the prospect of photographing birds.  Both dragons and hoppers are amazingly intricate and photogenic insects, but I’ve been struck repeatedly by my blatant taxonomic bias – I’d far rather find and photograph odes than I would orthops.  Notwithstanding the fact that orthopterans include some of the most striking and beautifully colored insects in the world, and at the other end of the extreme orthops that are exquisitely cryptically colored to blend with their surroundings, an equally astounding feat of adaptation.  Still, for me, dragonflies are the shit.   It’s an incredibly overused metaphor, but I’ll use it anyway – dragonflies are the attack helicopters of the insect world.  I remember seeing Coppola’s opus Apocalypse Now for the first time (and many times thereafter), marveling at the incredible cinematography.  While watching with mouth agape as Colonel Kilgore and the air cavalry attack the point where the waves break in both directions (“Charlie don’t surf!) to drop Willard and his PBR crew into the mouth of the Nung, I remember thinking that the Hueys in slow motion were like nothing so much as giant dragonflies.  The precision and power of odonate flight is awesome, and they are some bad, badass predators.   Seeing one ode munching on another nearly its own size makes me very happy they don’t get any bigger than they do.  Magnificent animals.

Halloween pennant, Cellithemis eponina.  An absolutely gorgeous insect.

Halloween pennant, Cellithemis eponina. An absolutely gorgeous insect.

On the other hand, orthops are the heavy equipment of the insect world, to me.  Generally slow, lumbering, inoffensive and unaggressive – all fine qualities for an animal, but not as likely to arouse my intense awe as those of rapid and wary predators.  But orthops are charming, colorful and diverse beasts that frequent weedy roadsides, so how could I pass them up?

Atlantic grasshoppers, Paroxya clavuliger, procreating.

Atlantic grasshoppers, Paroxya atlantica, procreating.

The pursuit of odes provides me a whole new treasure trove of lifer organisms to see and photograph, like this Amanda's pennant (Cellithemis amanda) I saw for the first time a week ago

The pursuit of odes provides me a whole new treasure trove of lifer organisms to see and photograph, like this Amanda’s pennant (Cellithemis amanda) I saw for the first time a week ago

And every now and then, I see other cool critters, like spiders, and owlflies.  I may be more taken with the spiders than I am with the odes these days.   But that’s another post.

Ululodes florida_09162014-07_Tiger Bay RR

The Florida owlfly, Ululodes floridanus

One of the unanticipated benefits of immersing myself into new taxa to explore and photograph is that it delivers a big dose of humility.  It doesn’t take long to realize how little I actually knew about them before, and how much there is in front of me to learn.  And that’s cool.

Blue dasher obelisking.  In obelisking behavior, the ode points its abdomen directly at the sun to prevent overheating

Blue dasher obelisking. In obelisking behavior, the ode points its abdomen directly at the sun to prevent overheating

Katydid on Centrosema

Katydid on Centrosema

 

Things didn't work out so well for this skimmer.  That's a green lynx spider (Peucetia viridans) that has ambushed this ode from an inflorescence of ten-angled pipewort, Eriocaulon decangulare

Things didn’t work out so well for this skimmer. That’s a green lynx spider (Peucetia viridans) that has ambushed this ode from an inflorescence of ten-angled pipewort, Eriocaulon decangulare

Schistocerca grasshopper nymph kicking off his old skin

Schistocerca grasshopper nymph kicking off his old skin

Common and stunningly beautiful - golden-winged skimmer, Libellula auripennis

Common and stunningly beautiful – golden-winged skimmer, Libellula auripennis

 

Sceliphron caeme_08032014-49_620 COC

Looking for a miracle

 August 4, 2014

Watching this Sceliphron mud dauber provision and seal off her sixth cell inspired me to document her building of Cell 7.

Watching this Sceliphron mud dauber provision and seal off her sixth cell inspired me to document her building of Cell 7.

I’m one of those paganistic sorts whose main source of spiritual enrichment is my observation of and interaction with the natural world. Forget about talking snakes and burning bushes – I witness the miraculous every time I’m in the field. In the last day, I’ve watched a miracle unfolding without even leaving my house.

A couple of weeks ago a female black-and-yellow mud dauber, Sceliphron caementarium, began building a nest in the frame of my sliding glass door. To get there, she had to come into my glassed lanai while the glass panels were open. Once I noticed her building her first cell, I began leaving the glass room open as much as possible to allow her to continue her work. I think mud daubers are one of the first insects I learned to identify as a kid, before I had any real organized knowledge of nature. They are that common. Everyone knows them. I’ve always thought that the common Sceliphron in Florida, S. caementarium, is a particularly elegant looking wasp, and I knew the basics of their reproductive biology, but I’d never had the opportunity to watch one build at length.

Sceliphron caementarium, the black-and-yellow mud dauber.

Sceliphron caementarium, the black-and-yellow mud dauber.

For the next couple of weeks, my patio female added several more cells, and I frequently saw her flying in and out of the patio carrying mud balls. Yesterday, as she completed the sixth cell, I watched through binoculars from my living room couch as she provisioned the completed cell with a big green spider, and then a few minutes later capped it off with more mud. It was so amazing to watch I decided to set up on her and photograph her as she built, provisioned, and sealed her next cell. It took her between about 5:30 on Sunday evening and noon Monday to complete the task. It was a miracle.

The engineering and architectural feats of hymenopterans, the ants, bees, and wasps, are well known and all are worthy of marvel and awe. The fungus gardens of leafcutter ants, paper wasp and hornet nests, the hives of honeybees – all employ sophisticated design principles to achieve their ultimate goal, production and nurture of the next generation. But these are the works of colonial species, contributed to by dozens-millions of individual organisms. Solitary wasps like Sceliphron are perhaps even more awe-worthy simply because each female is on her own. She builds a stone castle for her children entirely by herself.

Larra bicolor, a deliberately introduced species of wasps that preys on mole crickets.

Larra bicolor, a deliberately introduced species of wasps that preys on mole crickets.

There is a huge diversity of solitary wasps, many of which share a common lifestyle – they build or dig some kind of nursery chamber in which to lay eggs, and then they provision the eggs with paralyzed insects of some sort that will be the larval food source. Cicada killers are one of the more obvious examples, but other provisioning wasps specialize on a variety of prey. Some specialize on caterpillars, others on crickets. Just a couple of weeks ago I found and photographed a beautiful crabronid (in the family Crabronidae) wasp that I had never seen before called Larra bicolor. This metallic black-and-red wasp was imported from South America in the 80’s and 90’s to control populations of non-native mole crickets. That’s how specific they are in provisioning their offspring – they hunt only mole crickets, which they temporarily paralyze with their sting. They lay an egg on the cricket, and when it recovers, it goes on its merry mole cricket way, now carrying a parasitoid wasp larva that will eat it from the inside out as it develops. Larra bicolor is so specialized in host choice that they attack non-native mole crickets almost exclusively; they ignore the native species of mole cricket, which as it turns out are attacked by a different, native species of Larra.

Liris wasp with paralyzed Gryllus cricket.

Liris wasp with paralyzed Gryllus cricket.

Last week, I saw another cricket specialist wasp in the genus Liris dragging a paralyzed cricket across the hammock floor at Beresford Park. Liris wasps attack only crickets in the genus Gryllus.

Leucage venusta, a common orb-weaver (Family Araneidae) in Florida.  Sceliphron wasps prey on a number of orb-weavers.

Leucage venusta, a common orb-weaver (Family Araneidae) in Florida. Sceliphron wasps prey on a number of orb-weavers.

Lovely Sceliphron is a spider specialist. They provision their nest chambers, or cells, with a mess of paralyzed spiders, which will feed the single larva that hatches in each cell. They exploit a variety of spider species, including both web-building and non-web spiders. But before they can do that, they have to build the chamber. They do this one cell at a time, which is provisioned, oviposited in, and sealed off before the next cell begins. That means that at numerous points some behavioral switch is engaged, and the female abruptly shifts her focus.

Bringing in mud for one of the lower courses.

Bringing in mud for one of the lower courses.

First they must locate a suitable site; the one inside my patio was much lower than most I’ve seen, making it convenient for watching. Once a site is procured, the first switch is thrown, and they begin collecting mud. It seems to be a very consistent form and composition of mud, as the nests are incredibly uniform looking once completed. My female began building Cell 7 a little before 5:30 on Sunday evening, and completed it at about 7:45. During that time, she delivered and installed a new mud ball every 5 minutes or so. She was so regular during most of this time that I actually set my microwave timer for 4 minutes each time she left, and during that time futzed around the house, rushing back to the tripod-mounted camera when the alarm went off. Usually, she would reappear like clockwork within 15-30 seconds after I positioned myself. So to complete one cell she made somewhere between 25-30 mud-gathering trips.

Building the cell wall.

Building the cell wall.

Shaping the clay.

Shaping the clay.

Behavioral switch 2, from mud-gathering to building. The building process is remarkably delicate and precise. She deposits each mud ball on one side of the growing tube, and then manipulates it with her mandibles into a thin ribbon that adds to the length of the cell. The dexterity with which she accomplishes this task is impressive. It takes her less than a minute to form each mud deposit, and then she’s off for more. But interestingly enough, she never leaves immediately after finishing the latest course – she always entered the growing cell first, perhaps touching up the inside seams, and then emerged, usually to wander around the nest for a few seconds before launching into space to gather another mud ball.

She entered the cell after each course was finished before flying away.

She entered the cell after each course was finished before flying away.

Behavioral switch 3. She cycled between mud-collecting and building for the next couple of hours. The last I saw of her on Sunday evening was around 7:45. The females sleep away from the nest; my plan was to be back on the nest at first light so as not to miss the next stage, provisioning. I didn’t know what time that might be. I was an earlier riser than she. I first saw her around 8:15, and then apparently only for a final inspection of the now hardened cell. She spent a minute or so walking around her castle, and then took off.

The cell grows.

The cell grows.

Grooming after completing the lip of the cell.  She often groomed for a few seconds after finishing a course.

Grooming after completing the lip of the cell. She often groomed for a few seconds after finishing a course.

Inspecting the newly-hardened cell at 8:15 in the morning.

Inspecting the newly-hardened cell at 8:15 in the morning.

Behavioral switch 4. She was in hunting mode. Which apparently is not as regular and predictable as mud-gathering. I was hoping she would bring a spider in every five minutes or so, but it wasn’t until after 11 that I first saw her again. She was carrying a rather large green lynx spider, with its legs bent upwards over its back and almost parallel to each other. The wasp somehow did that, apparently, to make transport easier.

She delivers with a big juicy lynx spider.

She delivers with a big juicy lynx spider.

Green lynx spider enjoying happier times.

Green lynx spider enjoying happier times.

Preparing for insertion.

Preparing for insertion.

Behavioral switch 5. Insertion. It took her a minute or so to position the spider and drag it backwards into the cell. Somehow she was able to get it in, legs last, position it inside and then exit herself from the hole. That was the only spider I saw her bring to that cell, though it’s possible I missed other deliveries because of her somewhat rude and inconveniencing loss of regularity. I did see her come back a couple of times and spend several minutes trying to tuck the ends of the protruding spider legs completely into the cell. So as far as I know, that larval wasp has only one spider to feed on, though in some cells there may be several spiders. In the Sceliphron species whose provisioning behaviors have been well-studied, the amount of food supplied for each cell is quite consistent, and based on total mass of the spiders delivered, not volume of the cell or number of individual spiders. So while the wasp is in provisioning mode, she is also keeping track, somehow, of the total weight of spiders she has delivered to that cell. Miraculous.

Come into my parlor, said the wasp to the spider.

Come into my parlor, said the wasp to the spider.

Not as easy as it looks.

Not as easy as it looks.

Dealing with those pesky legs.

Dealing with those pesky legs.

She seemed somewhat befuddled about how to deal with the protruding legs.  So she groomed.

She seemed somewhat befuddled about how to deal with the protruding legs. So she groomed.

Finally, behavioral switch 6. Capping. She seals off the cell by resuming the mud-gathering/buildingcycle. Watching her build the tube course by course was impressive, but seeing her turn that round ball of mud almost instantaneously into a cap of even thickness was even more so. She delivered five separate mud balls to complete the seal, thickening it with each new load, and in the last couple buttressing it to the surrounding cells. And then she looked upon her work and saw it was good. Seriously. After the last buttressing load, she spent what seemed like a longer period of time than usual wandering around her castle inspecting it. I actually thought while she was doing it that she had completed that cell. And she had. It was a bit after noon.

First mud ball forming the cap.

First mud ball forming the cap.

Smoothing the cap.

Smoothing the cap.

Off for more mud.

Off for more mud.

Mud load # 27.

Mud load # 27.

Thickening the cap.

Thickening the cap.

Buttressing the cell.

Buttressing the cell.

She began working on Cell 8 at about 1:30, and is still building the tube as I write this. Which involved another behavioral switch, returning to site-selection mode. I suspect the last inspection period was part of the decision-making process regarding where in the structure the next cell should go.

Sceliphron caeme_08042014-20_620 COC

Sceliphron exhibits a remarkably sophisticated and precise chain of behaviors, most of which must be innate. Once she has completed all of her cells (which can range from less than 10 to over 40), she leaves her castle and offspring on their own. If her babies successfully navigate larvahood, they will emerge from their cells knowing exactly how to do everything their mother did. If they are females, that is. If they are males, on the other hand, all they have to know is how to hang around on the corner like a hoodlum and try to entice a female to accept a load of sperm. The disparity should be troubling and revolting to all decent folk.

Sceliphron caeme_08042014-02_620 COC

Regardless of sex, though, nearly all of the operating instructions for these complex little beauties are encoded in the genes. Which is not to say that they are incapable of learning, and increasing their skill and dexterity with experience –  learning must be involved in some aspects of their behavior. They must find a suitable nest site, and remember where it is and how to return to it from each collecting/provisioning trip. Still, a stunning amount of information must somehow be stored in the form of DNA, the primary function of which is to encode information allowing cells to build specific proteins. So, all of those complex and sophisticated behaviors are ultimately the result of the activities of specific proteins that constitute the major building blocks and functional components of all cells and tissues. And that is truly a miracle.

 

NOCA sunning_071611_4_620 COC

Hot birds

NOCA sunning_07112014-08_620 COC

July 11, 2014

A young northern cardinal visits a feeding tray exposed to full sun, around mid-day.  She begins to pick through the variety of seeds, but after a few moments of feeding, her behavior changes as if someone threw a switch.  She stops sorting seeds, leans strongly to one side, cocks her head at an angle so that she appears to be looking directly at the sun with one eye, and she fans out her wings and tail while fluffing out most of her body plumage.   She holds this posture for a half-minute or two, and then resumes normal feeding.  Over the next several minutes, she adopts this stereotyped posture several more times, sometimes lying flat on her abdomen and extending both wings to the side.  Each time she switches from feeding to posturing, the transition is almost immediate.  It’s very amusing to watch. 

Cardinals frequently switch between feeding and sunning when at the feeder. Mourning doves seem to restrict their sunning behavior to the ground.

Cardinals frequently switch between feeding and sunning when at the feeder. Mourning doves seem to restrict their sunning behavior to the ground.

This hen cardinal is engaging in sunning, a widespread yet poorly understood behavior.  Sunning postures of various sorts have been reported in over 50 families of birds.  Way back in 1957, Doris Hauser published a paper reporting her observations of sunning behavior in 33 species of birds from Florida and North Carolina.   In the last several decades there has been a lot of research on thermoregulation in birds and the importance of basking behaviors in regulating body temperature, yet there has been very little peer-reviewed research on the types of sunning behavior Doris Hauser documented.  It’s still not clear why they do it.

Anhingas bask to dry their wings and to supplement their low metabolic rates.

Anhingas bask to dry their wings and to supplement their low metabolic rates.

The most obvious explanation is simply regulation of core body temperature; birds are mostly endothermic (“warm-blooded”), using metabolic heat to maintain a high body temperature.  However, many birds use ectothermy (use of external sources of heat to regulate body temperature) occasionally to supplement their metabolically-derived heat, and lower their energy needs by doing so.   Both turkey and black vultures are frequently seen basking in the morning before they leave the roost.  Roadrunners have a characteristic body posture they use to bask early in the morning; basking birds reduce their metabolic rate by up to 40% compared with other roadrunners in the same conditions that aren’t basking.   Anhingas and cormorants both use stereotyped, spread-wing basking postures to aid in drying their wings after diving. 

Black vulture basking

Black vulture basking

Turkey vulture basking

Turkey vulture basking

But that’s not what the hen cardinal was doing, or the other species in Hauser’s study.  In all of these birds, sunning is most frequent when air temperatures are high, and the bird is in strong, direct sunlight.  Using external heat to maintain their body temperature isn’t needed in these conditions – the bigger problem for birds sunning at mid-day is keeping their body temperature from rising too high.  Many species engage in gular flutter or panting while they are sunning; these behaviors increase the flow of air over their mouth and throat, evaporating water and cooling the bird off in the process.   So these birds are adopting postures that expose as much body or feather surface as possible to direct sunlight, and in the process are absorbing so much heat that they have to use evaporative cooling to prevent overheating.   It doesn’t sound like body temperature regulation is the main adaptive function for my cardinal hen.  I see this same behavior, with the same general pattern of occurrence, in red-bellied woodpeckers, mourning and ground doves, blue jays, northern mockingbirds, Carolina wrens, tufted titmice, and cardinals. 

Many birds pant and perform gular flutter while sunning, an indication that their core body temperature is in danger of rising dangerously high.

Many birds pant and perform gular flutter while sunning, an indication that their core body temperature is at risk of rising dangerously high.

NOCA sunning_072111_1_620 COC

Northern cardinals will sun on the ground.

Northern cardinals will sun on the ground.

The transition between other behaviors and sunning can be so abrupt that it seems to occur almost as an involuntary reflex in response to a specific set of environmental conditions, including ambient temperature and strength of insolation.  Hauser suggested that there are actually two behaviors involved – voluntary and compulsive sunning.   I’m not sure if many bird physiologists or behaviorists buy the latter, but it’s easy to see how she came to this conclusion; initiation of sunning behavior often appears as if it is beyond the bird’s conscious control, as if some internal switch were thrown and they are compelled to obey the urge.

Blue jays get into sunning in a big way.

Blue jays get into sunning in a big way.

Sunning postures can be partial or complete. This Carolina wren has cocked his head to increase insolation, but hasn't done the complete prostrate collapse yet.

Sunning postures can be partial or complete. This Carolina wren has cocked his head to increase insolation, but hasn’t done the complete prostrate collapse yet.

Other benefits of sunning have been suggested.   Components of preen oil have been shown to convert to Vitamin D when exposed to sunlight, which may then be ingested when the bird preens; direct insolation of exposed skin almost certainly increases Vitamin D production by the cells of the epidermis, as it does in most vertebrates.  

Juvenile mockingbird in partial sunning posture.

Juvenile mockingbird in partial sunning posture.

The explanation that makes most sense to me is that sunning is a way of controlling ectoparasites, like feather lice, mites, fleas, and ticks.   The idea is that what the birds are doing is heating their skin and feather surfaces to high temperatures that the bird can endure for short periods of time, but the parasites can’t.  High skin/feather temperatures may kill some ectoparasites directly, or it may cause them to move around more trying to avoid the heat, allowing the preening bird to pick them off more easily.  Sunning behavior is often combined with bouts of preening. 

Many birds preen or scratch immediately after sunning, perhaps because ectoparasites are moving around on their skin in response to the heat.

Many birds preen or scratch immediately after sunning, perhaps because ectoparasites are moving around on their skin in response to the heat.

Mourning dove peek-a-boo sunning posture

Mourning dove peek-a-boo sunning posture

MODO sunning_012912_0_620 COC

The only experimental study I’m aware of testing this idea used artificial wings made from feathers of black noddies (a widespread oceanic tern), that were exposed to two conditions – sun vs. shade.  The researchers placed feather lice collected from wild noddies on the wing feathers, and recorded their fate.  Wings “basking” in the sun reached temperatures high enough to kill about half of the lice, while lice on wings in the shade all survived.   It’s not surprising that black noddies spend a lot of time in their stereotyped sunning postures. 

The ectoparasite hypothesis and the Vitamin D hypothesis are not mutually exclusive; it’s entirely possible that birds involved in sunning are increasing their fitness in multiple ways.

The delta-wing or droop-wing sunning posture in a great blue heron

The delta-wing or droop-wing sunning posture in a great blue heron

An open-beak posture is often a sign that the bird is overheated, and using evaporative cooling from the respiratory surfaces to cool down.

An open-beak posture is often a sign that the bird is overheated, and using evaporative cooling from the respiratory surfaces to cool down.

The taxonomic range of birds that use some form of sunning posture, presumably to control parasites, is broad.  For many years I puzzled over the basking behavior I sometimes see in great blue herons, in which the bird faces the sun and droops its wings to the side to form a sort of parabolic dish with which to collect sunlight.  I nearly always see this behavior in hot weather, rarely in cold.   The herons are nearly always engaged in gular flutter, bills agape to dissipate excess heat.    The apparent paradox of birds basking to the point of hyperthermia had me scratching my head for a long time.  I still scratch my head a lot, but for new and improved reasons.

References

Clayton, D. H., Koop, J. A., Harbison, C. W., Moyer, B. R., & Bush, S. E. 2010. How birds combat ectoparasites. Open Ornithology Journal: 3, 41-71.

Hauser, D. C. 1957. Some observations on sun-bathing in birds. The Wilson Bulletin, 78-90.

Moyer, B. R., & Wagenbach, G. E. 1995. Sunning by Black Noddies (Anous minutus) may kill chewing lice (Quadraceps hopkinsi). The Auk, 1073-1077. 

CEWA feed ritual_05262014-23_Silver Lake CP

Old birds, new behaviors

 

May 31, 2014

I do most of my birding and natural historizing locally, only occasionally traveling more than 30 miles to a birding destination.   Once a year, though, I drive to northern Virginia sometime in May to hang out with my father for a week or so and experience the explosion of breeding bird activity in that part of the country.   One of the rewards of making this pilgrimage is the opportunity to experience new behaviors of species that winter, but don’t breed, in Florida.   There are a lot of those.  Although I mostly grew up in northern Virginia, and discovered my obsession with birds there, I’m still surprised on most visits by finding species or seeing behaviors that I somehow missed while I was living there.  Cedar waxwing breeding behavior is a case in point.

Silver Lake, in Haymarket, VA

Silver Lake, in Haymarket, VA

In the last couple of years, I’ve started visiting a new site while in Virginia – a county park that was only recently opened to the public.  Silver Lake Regional Park, in Haymarket, Virginia, opened in 2009, and has become one of my favorite birding spots when I’m in the area.  At 230 acres, it’s a postage stamp of a park.  Silver Lake is a 23-acre impoundment fed by Little Bull Run, and the surrounding piedmont is a mosaic of mostly disturbed and successional habitats.   Breeding bird communities of so-called old field habitats in the mid-Atlantic region contain a number of charming birds, and the diversity and density are high enough that during May there is nearly always something happening worthy of watching.  At Silver Lake, there is a large parking area that is designated for horse trailer parking, which abuts a lovely tract of perhaps 20-30 acres of prime old field habitat in the shrub-sapling stage of succession.   I rarely see anyone else at this end of the park; most park visitors cluster around lovely Silver Lake to fish.  So I have this beautiful shrubby old field all to myself.

Cemetery Cedar C_05192012_08_Aden VA

When agricultural land is abandoned and allowed to revert to a natural state, it undergoes a predictable sequence of changes in plant composition, vegetative structure, and characteristic breeding bird communities, called secondary succession.  The first few years of succession are characterized by low stature vegetation consisting entirely of herbaceous grasses and forbs; because of the simple, monolayer structure, the breeding bird community is low in diversity, often consisting of only a few species (grasshopper sparrows and eastern meadowlarks, for example) at relatively low densities.  Within 5-10 years, woody plants begin to invade and become a prominent component of the vegetative structure; these invaders include species such as red cedar, wild cherry, and persimmon, among others.  The increase in vegetative complexity, and concomitant increase in the amount and variety of food resources for birds, results in a big jump in breeding bird diversity, as species like indigo buntings, blue grosbeaks, song and field sparrows, brown thrashers, common yellowthroats, and yellow-breasted chats establish breeding populations.  The density of breeding pairs also increases nearly three-fold between the grass/forb stage of succession and the shrub-sapling stage.  All of the various stages of succession from abandoned field to mature deciduous forest have their own characteristic bird communities; diversity and density of breeding birds is greatest in late successional habitats, which in northern Virginia means various incarnations of eastern deciduous forest.

The average number of species breeding in four stages of secondary succession in the eastern U.S. (from May, 1982)

The average number of species breeding in four stages of secondary succession in the eastern U.S. (from May, 1982)

Grasshopper sparrows are characteristic breeders of very early successional habitats

Grasshopper sparrows are characteristic breeders of very early successional habitats

FISP_05262014-27_Catharpin VA

Field sparrows don’t begin breeding in old field habitats until woody plants have begun to invade.

Where you find breeding field sparrows, you usually find prairie warblers as well

Where you find breeding field sparrows, you usually find prairie warblers as well

The density (number of territorial males/40 hectares, or about 100 acres) at four stages of secondary succession.

The density (number of territorial males/40 hectares, or about 100 acres) at four stages of secondary succession.

Density and diversity of breeding birds generally increase in a predictable pattern with successional age of the habitat, with the greatest abundance and diversity occurring in the so called “climax stage”, which remains relatively stable in plant composition unless it is disturbed by either natural events (fire, blowdowns, etc.) or anthropogenic causes (deforestation).   In the mid-Atlantic region, the climax plant community in many parts of the landscape is some form of eastern deciduous forest. (The concept of a climax community that is stable and unchanging over long time periods is eschewed by many ecologists; it’s a pretty simplistic idea.)  So even though it’s not the most diverse habitat type in the successional continuum, the shrubby stage of old-field succession is hard to beat for superb birding.  Not only are many of the birds breeding there interesting and beautiful, the relatively low stature of the vegetation and open architecture of the habitat make observation of bird activity far easier than in the more diverse mature forests.

Oak-hickory-beech forest is the terminal or "climax" stage of succession in parts of northern Virginia.

Oak-hickory-beech forest is the terminal or “climax” stage of succession in parts of northern Virginia.

So on two of the five mornings I was in Virginia, I found myself at Silver Lake Regional Park, ensconced in my car (a blind of sorts) to just sit and soak in the stunning beauty of spring in Virginia.   The primary object of my attention was the yellow-breasted chats that breed in this patch of habitat; I see chats only rarely in Florida, and then typically very briefly.  There are few bird species skulkier than a yellow-breasted chat.   That doesn’t change all that much when they are breeding, but they are such vocal birds that even if you can’t see them much of the time, you can keep track of their movement and activities by the nearly constant outpouring of croaks, grunts, whistles and other varied mechanical sounds these oversized warblers produce.  They do a killer imitation of a distant crow cawing; on several occasions, they momentarily fooled me with this call even though I knew I was listening to a chat.  They’re that convincing.  On my first visit to Silver Lake, I had a remarkable half-hour or so watching and listening to yellow-breasted chats that on occasion abandoned their skulkitude and FULLY EXPOSED THEMSELVES.  Amazing.

Yellow-breasted chat in mild skulk mode.

Yellow-breasted chat in mild skulk mode.

Yellow-breasted chat IN THE OPEN!!

Yellow-breasted chat IN THE OPEN!!

So it shouldn’t be hard to understand how I can easily pass an hour or two sitting by this patch of old field habitat, watching and listening to the comings and goings of the breeding birds. It was while I was doing just that on my second visit, parked next to a small copse of some fruit-bearing sapling, that I saw a pair of cedar waxwings fly into the dense cover at the back of the grove, nearly hidden from sight.  Cedar waxwings are a species that I saw fairly regularly when I lived in Virginia, but always as nomadic flocks of fruit-scouring pirates during the non-breeding season.   At Silver Lake, though, they seem to be common breeders.  I had discovered a nesting pair of waxwings frequenting a dense clump of vine-tangled cedars on my first visit to Silver Lake, but those birds were in such dense cover that they were nearly impossible to observe when they were on or near the nest.

The male waxwing with his gift.

The male waxwing with his gift.

By contrast, this pair of waxwings in the little grove by the parking lot put on a show for me.  One of the birds, presumably the male, flew out of the back of the clump towards me, and snagged a pair of small, green fruits.  He was soon joined by his mate, and they began a ritualized behavior that was entirely new to me.   The male presented the unripe fruits to the female, which I interpreted as courtship feeding.  Cool to see, but not particularly unusual.   Many passerines and non-passerines perform similar ritualized feeding during courtship and pair-bond maintenance.  I see it every summer between the cardinals that breed in my neighborhood.   But the female didn’t eat the fruits – she moved away from the male a few inches and held it, then moved back to the male and passed it back to him.   He held them for a few seconds, then returned them to the female.   She followed suit.  For the next minute or two, they repeated this behavior at least 5 times.  Eventually one of the waxwings flew away; I don’t know if it was the male or the female that left first, or if he or she even ate the fruits.  It was a trip to see.

CEWA feed ritual_05262014-19a_Silver Lake CP

Waxwings show a number of distinctive aspects of their breeding behavior.   Anyone who has marveled at the antics of big flocks of waxwings wintering in Florida as they decimate the fruit crop on a chosen tree knows they are extremely social birds, and this extends to the breeding season.  They aren’t territorial when breeding, and sometimes nest in loose colonies of 10 or more breeding pairs.   Compared to most other passerines, they are among the latest to begin breeding activity.  Eggs aren’t usually laid until late May or early June, which seems to be an adaptation for synchronizing the appearance of the greedy youngsters to the availability of ripening fruit.  Waxwings are one of the few primarily frugivorous birds in North America; while many species feed on fruit opportunistically, none are as specialized to a fruit-eating diet as waxwings are.   They do incorporate more animal prey into their diet during the breeding season, probably for the protein content, but still fruit makes up a substantial portion of the diet of nestling birds.

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So this pair of birds engaging in repeated acts of fruit passing were likely still in the courtship/pair bonding stage of the nesting cycle.   The entry for cedar waxwings at Cornell’s Birds of North America Online site gives this account of the behavior I observed:

Typical courtship display in which mates alternately approach one another on a perch with hopping movements, sometimes touching bills. Usually initiated by male; successful when female reciprocates (Putnam 1949). This display is termed the Courtship Dance or Courtship-Hopping (Silloway 1904Crouch 1936Lea 1942). Courtship-Hopping begins in migrant flocks, and has been noted as early as Apr in California (Feltes 1936) and in Ohio (Putnam 1949). Courtship-Hopping often includes passing a small item (usually food item such as a fruit, insect, or flower petal, but sometimes inedible items, and occasionally object-passing may be merely simulated, with no object actually passed; Fig. 3) between male and female, interspersed with short hops away from and back toward mate. Display usually initiated by male, who obtains a food item and joins female at a perch (Putnam 1949). Male approaches female by hopping sideways and passes item to female with turn of head (usually both birds face same direction). Female typically hops away from male, then hops back and returns item to male. Male then responds by hopping away, often performing bowing movements between hops, before hopping back and repeating the sequence. The display may be repeated a dozen times or more (Tyler 1950) and is usually terminated when the female eats the food item (Putnam 1949). Bouts of courtship-feeding may be interspersed with fast circular flights around nest area. Crouch (1936) observed an apparent extension of passing behavior in which female would pass last food item back to male after he had delivered food to her, either at or away from nest. Then the mates would allopreen and bill. Copulation is usually preceded by Courtship-Hopping (Putnam 1949).”

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Though I saw no allopreening, circular flights, or copulation, I was ecstatic about observing this fascinating behavior.  One of the great joys of natural history study is knowing that even after observing a species, sometimes extensively, for years or even decades, there is always the potential for learning something new about them.

 References:

May, P.G.  1982.  Secondary succession and breeding bird community structure: Patterns of resource utilization.  Oecologia 55(2): 208-216.
Witmer, M. C., D. J. Mountjoy and L. Elliot. 1997. Cedar Waxwing (Bombycilla cedrorum), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online:  http://bna.birds.cornell.edu/bna/species/309