Sistrurus miliar_080712_5_L Woodruff NWR

Learning snakes

August 20, 2016

As naturalists, what we observe and learn is directly connected to how we look.  I spent more than a decade involved in field and laboratory studies of dusky pigmy rattlesnakes (Sistrurus miliarius barbouri), during which time I had the great fortune to observe thousands of these charming little pit vipers in both natural and captive environments.   Still, during all that time studying pigmies, I never witnessed a behavior I was able to watch yesterday morning while road-cruising the forest roads of Ocala National Forest.

Early morning in the scrub with the birds, later with the snakes. Life is good.

An early morning in the scrub of Ocala National Forest, first spending time with the birds, and later with the snakes. Life is good.

Most of my field observations of pigmies in years past took place during systematic group censuses of our primary study population.   A group of dedicated snake searchers moved slowly through the hammock habitat, looking for the sometimes abundant pigmies, most of which were individually marked as part of a long-term mark-recapture study.  The premium was on finding as many snakes as possible during the census, and measuring characteristics of the found snakes, such as location, substrate, length, weight, and so on.  The upside of this approach is you get to see a lot of snakes.   The downside is that you don’t get to watch individual snakes very long before you’re on to the next one.

This adult dusky pigmy rattlesnake is in a typical foraging coil.

This adult dusky pigmy rattlesnake is in a typical foraging coil.

Not that watching individual snakes is a very productive use of time, in general.   Pigmy rattlesnakes normally don’t do much most of the time.  They are classic ambush predators, and will sometimes remain in a foraging coil without moving for days at a time.   The majority of snakes found are coiled and waiting for some unsuspecting frog or lizard to foolishly venture within striking range.    The frequency of pigmy rattlesnake movement varies seasonally; in winter and summer months, only 5-10% of snakes found are moving (May et al., 1996).   The remaining 90-95% are in foraging coils.  The proportion of moving snakes rises to as high as 15% in spring and fall, but at any time of year, most of the snakes that are out and about (as opposed to sheltering under cover) are immobile.    So watching a foraging pigmy rattlesnake is, for the most part, a lot like watching paint dry.   Observing the snakes that were moving when first seen isn’t much more productive; they are nearly always aware of the human observer’s presence, and when they resume movement, their goal is mostly to get to cover and out of sight.

Pigmy rattlesnakes move relatively infrequently most of the time.

Pigmy rattlesnakes move relatively infrequently most of the time.

Yesterday morning began not long after sunrise, as I started the first day of data collection for my sabbatical research.  The focus of this study is bird behavior, and in particular the effectiveness of different auditory cues in eliciting mobbing responses of passerine birds.   Snakes were not the furthest thing from my mind (they rarely are), but I wasn’t thinking as much about snakes as I was about birds.  A couple of hours of playback trials occupied me for the early part of the morning, and produced a few cool birds – lots of northern parulas, several prairie and yellow-throated warblers, a couple of FOS ovenbirds, and at least a half-dozen summer tanagers.  In addition to the neotropical migrants, year-round residents were in evidence everywhere – lots of Florida scrub jays, including many scruffy gray-headed youngsters, tons of towhees, and frequently heard, infrequently seen white-eyed vireos.  By 9:45 or so it was hot enough that bird activity was on the wane, so I gave up the structured protocol of research and switched to random road-cruising fun.

Yellow-throated vireo and yellow-throated warbler, traveling together in the scrub. Mixed-species flocks consisting of up to a dozen species are the basic functional unit of mobbing behavior.

Yellow-throated vireo and yellow-throated warbler, traveling together in the scrub. Mixed-species flocks consisting of up to a dozen species are the basic functional unit of mobbing behavior.

A couple of distant, rapidly moving black racers were the only snakes I found crossing Forest Road 33; at about 10:30 I headed east on FR 46 towards its intersection with SR19, and then home.  It was warm enough I didn’t expect to see much bird or other wildlife activity, but I was ready to be pleasantly surprised.  I saw a bear on this road around mid-day last fall, so anything is possible.

A scrub lizard, Sceloporus woodi, led me to the baby pigmy, much like the African honeyguide leads people to beehives.

A scrub lizard, Sceloporus woodi, led me to the baby pigmy, much like the African honeyguide leads people to beehives.

I slowed a bit at the Pat’s Island Trailhead parking lot, and when I did so, I saw a lizard dart from the soft sand at the road’s edge towards cover.  He stopped briefly in the open, and I maneuvered my big lens into position to scan the ground for the saurian.  I found him, briefly, before he retreated fully into cover and out of sight.  It was a male scrub lizard (Sceloporus woodi), a Florida endemic that, though locally abundant, always gets me a little hyped when I get the chance to photograph one.   Which this guy refused to give me.   But while scanning the ground for the cryptic scelop, I saw something else I would have completely missed with a naked eye view – a neonate pigmy rattlesnake stretched out on the sand and debris.  The small size and bright yellow tail identified it as a YOY – a young-of-the-year snake that was almost certainly less than a month old, perhaps no more than a few days old.  It still had only the original button that rattlesnakes are born with, meaning it had shed its skin only once (the post-natal shed, which comes 2-4 days after birth and leaves the snake with a single rattle segment).  His second shed would add the first interlocking rattle segment below the button, and and would allow this snake to actually rattle, sort of, if it chose to.  Which they rarely do.   Pigmy rattlesnakes are kind of an embarrassment to the whole notion of rattling.

My first view of the baby pig.

My first view of the baby pig.

The "rattle" of my baby rattler. No moving parts - he couldn't rattle if he wanted to. Which he didn't.

The “rattle” of my baby rattler. No moving parts – he couldn’t rattle if he wanted to. Which he didn’t.

As is typical of pigmies that are detected by a big stinking primate while they are moving, this one had frozen into complete immobility.   Such snakes are acutely aware of the sweaty mammal, and usually will remain static and somewhat cryptic for a minute or three; at some point, they apparently decide (?) that the threat is diminished and gone, and they slowly crawl to cover.   But this one didn’t do that.

Instead, it began poking its head around the palm frond debris nearby, tongue-flicking occasionally.  After a couple of minutes of exploratory behavior, he slowly formed his body into a foraging coil.  This process took several minutes, and was completed as the little snake rocked his body back and forth a few times to settle down into the sand.  It was of interest to me that when the coil was complete, the yellow-tipped tail wasn’t particularly prominent.   Young pigmy rattlesnakes sometimes use their brightly colored tail tip to mimic a small caterpillar or insect larva, wiggling it when frogs or lizards are nearby to entice them into taking a bite.  If all works according to plan, the pigmy then takes his bite.  The behavior is called caudal luring; the baby pigmy I was watching wasn’t doing it.

Exploratory behavior.

Exploratory behavior.

Beginning the coil.

Beginning the coil.

Tighten up.

Tighten up.

A rocking little snake.

A rocking little snake.

The final result. Notice that the yellow tail is barely visible from the direction the snake is facing.

The final result. Notice that the yellow tail is barely visible from the direction the snake is facing.

A neonate pigmy rattlesnake from Lake Woodruff NWR in a foraging coil, showing a bit of the yellow tail.

A neonate pigmy rattlesnake from Lake Woodruff NWR in a foraging coil, showing a bit of the yellow tail.

So at this point I figured the excitement (!) was over.  The baby pig was settled into its foraging coil, and might not move for hours or days.  Still I hung around and watched.  I was hoping the scrub lizard might make a reappearance, but didn’t really expect any other action from the pigmy.  Still, I was pretty happy with what I’d seen so far.  In all the years of watching pigmy rattlesnakes in the field, I had never observed one actually form a foraging coil while I watched.   The tongue-flicking prior to coiling suggest that chemical cues may be an important part of site selection.  Eric Roth showed over a decade ago while working on the pigmy research project that pigmies are more likely to coil and hunt in areas that have been sprayed with frog scent than in nearby similar areas lacking frog odors (Roth et al., 1999).

Pigmy rattlesnakes in some habitats eat a lot of frogs, including both semi-aquatic frogs (leopard frogs, especially) and tree frogs. This a pinewoods tree frog, Hyla femoralis.

Pigmy rattlesnakes in some habitats eat a lot of frogs, including both semi-aquatic frogs (leopard frogs, especially) and tree frogs. This a pinewoods tree frog, Hyla femoralis.

I was quite surprised when the little viper began moving his head back and forth a bit, and tongue-flicking.  He had been in his coil for less than 5 minutes.  When he initially coiled, the spot was in shade, but a moving sun fleck was beginning to encroach on his foraging site.   That particular foraging spot would be completely untenable if exposed to full mid-morning sun; the little pigmy would be overheated within minutes.

Moving to a new foraging site. Check out the stick. Good call.

Moving to a new foraging site. Check out the stick. Good call.

So the little dude did a very reasonable thing – he switched spots.  But not very far.  He slowly crawled to a still shaded spot less than a foot away, and repeated the behavior.  He began nosing at and tongue-flicking around a small twig, and soon settled into a foraging coil situated partially under the stick.  The process of forming a coil was much quicker this time.  Time stamps from the series of photographs I took reveal that it took him several minutes to form the first coil, but only a little over a minute for the latter.He was still in his second coil when I drove away, but I doubt he stayed there long either. The entire area was soon to be exposed to direct full sun, which would surely require that he relocate again.

Scoping out the new neighborhood.

Scoping out the new neighborhood.

Beginning to coil.

Beginning to coil.

The second bout of coiling happened much faster than the first.

The second bout of coiling happened much faster than the first.

Coil nearly complete, but the tail is still exposed.

Coil nearly complete, but the tail is still exposed.

Coil complete, tail hidden. This is how I left him.

Coil complete, tail hidden. This is how I left him.

Was this baby snake learning how to choose a foraging site?   Snakes as a group have never been considered by most biologists to be particularly “intelligent”, whatever that term means.   The general view of comparative intelligence among the vertebrates has long been that while birds and mammals are highly intelligent and capable of complex cognitive feats (“learning animals”), the ectothermic vertebrates (fish, amphibians, reptiles) are primarily “reflex animals”, relying mostly on hard-wired, fixed behaviors to respond to environmental challenges.  My personal view is that we probably underestimate the cognitive capabilities of most animals.   There’s shit going on there we have very limited means of studying and understanding.

Are older pigmy rattlesnakes smarter than younger ones? What is animal intelligence?

Are older pigmy rattlesnakes smarter than younger ones? What is animal intelligence?

From a purely practical standpoint, it seems reasonable that young pigmy rattlesnakes should learn how to choose better foraging sites as they get older.  A successful foraging site, particularly one that results in capture and consumption of a prey item, should provide positive reinforcement regarding the characteristics of that foraging site, and the site-selection behavior of that individual should be modified.   Actually demonstrating learning by individual animals is a tough nut, though, especially in the field.  For learning to have occurred, the snake would have to modify some aspect of its site selection behavior as a result of earlier experiences.

Snakes in the genus Thamnophis (garter and ribbon snakes) have been shown in laboratory studies to learn how to better track prey. This is a peninsula ribbon snake (Thamnophis sauritus sackeni) trying to hang on to an uncooperative leopard frog. Scanned from a transparency.

Snakes in the genus Thamnophis (garter and ribbon snakes) have been shown in laboratory studies to learn how to better track prey. This is a peninsula ribbon snake (Thamnophis sauritus sackeni) trying to hang on to an uncooperative leopard frog. Scanned from a transparency.

Demonstrating learning in non-human animals requires controlled conditions and laboratory studies.   A quick and dirty Google Scholar search for primary literature on learning in snakes turns up only a handful of citations, some of which show limited modification of behavior based on experience, and others that don’t.  Garter snake babies become better at following worm trails with experience, but Richard Shine and his colleagues have shown that Australian black snakes (Pseudechis porphyriacus) don’t learn to avoid toxic cane toads (a novel, non-native prey for these snakes) after encountering them.  However, populations exposed to the toads rapidly evolved behavioral avoidance of cane toads, compared to populations with no previous exposure to the toads (Phillips and Shine, 2006).  The naïve snakes readily consumed the toads, much to their detriment. This result suggests that toad avoidance in these snakes is an evolved, genetically based behavior.

It would be an extremely premature and foolhardy conclusion to state with any confidence that I had observed a snake learning. None the less, I’m pretty sure that’s what I did.

 

 

References

May, P.G., Farrell, T.M., Heulett, S.T., Pilgrim, M.A., Bishop, L.A., Spence, D.J., Rabatsky, A.M., Campbell, M.G., Aycrigg, A.D. and Richardson, W.E., (1996). Seasonal abundance and activity of a rattlesnake (Sistrurus miliarius barbouri) in central Florida. Copeia, pp.389-401.
Roth, E., May, P., & Farrell, T. (1999). Pigmy Rattlesnakes Use Frog-Derived Chemical Cues to Select Foraging Sites. Copeia, 1999(3), 772-774.
Phillips, B. L., & Shine, R. (2006). An invasive species induces rapid adaptive change in a native predator: cane toads and black snakes in Australia.Proceedings of the Royal Society of London B: Biological Sciences,273(1593), 1545-1550.

 

 

GCFL_06162015-26_Camp Winona Rd

Daddy duties

Great crested flycatchers are monogamous, and strongly bonded. I nearly always see them traveling in pairs. That doesn't mean this male is going to share his cicada with the mate, though.

Great crested flycatchers are monogamous, and strongly bonded. I nearly always see them traveling in pairs. That doesn’t mean this male is going to share his cicada with the mate, though.

June 1, 2016

Birds are good parents.  Few other comparable taxa of animals, vertebrate or invertebrate, routinely provide a similar level of parental investment and care.   Mammals rival them; nearly all mammals retain developing embryos until birth, and provide lots of nurture and resources to the young once born (or hatched in the case of the monotremes).  Lactation is a physiologically demanding adaptation, but the costs are borne solely by mothers, except for a couple of bizarre cases in which male mammals lactate.  In mammals as a group, less than 5% of species show any male parental care.  To be sure, there is huge variation in the degree of male parental involvement in birds, ranging from none in promiscuous, lekking species like sage grouse and manakins, to complete male care in polyandrous birds like phalaropes, where female involvement in reproduction ends with the laying of eggs.   Still, on the whole, male birds are far more involved in providing parental care than in mammals.

Great crested flycatcher from Manassas National Battlefield Park. This species is monomorphic; the only way to differentiate males and females is by behavior.

Great crested flycatcher from Manassas National Battlefield Park. This species is monomorphic; the only way to differentiate males and females is by behavior.

I got a fascinating glimpse into the allocation of parental duties in great crested flycatchers while birding in northern Virginia last week.   These observations raise a number of questions about the significance of the male’s apparent participation in nest-building – is he really helping the female, which would constitute true parental investment, or is he simply acting in self-interest to protect his own fitness by preventing access by other males to his mate?   I’ll return to those questions in a moment.

Quite likely I wouldn’t have seen these neat behaviors in Florida, though they certainly occur here as well.  There is a huge difference between my birding tactics in Florida and Virginia.

Typical birding/photography setup for me - camera on the beanbag, waiting.

Typical birding/photography setup for me – camera on the beanbag, waiting.

I’m not a particularly patient birder or photographer.   I do much of my birding and photography from the car, for reasons that are obvious to anyone who knows me.  Run and gun is my preferred style.  If something isn’t happening at a particular site within 5 minutes or so, I tend to move on.  In the places I bird around DeLand, like Tiger Bay State Forest or Ocala National Forest, there is lots of habitat, good drivable roads, and few people.   There is no cost to changing locations.

Northern Virginia is a different beast entirely.  I return to Manassas, where I mostly grew up, once a year, usually soon after the spring semester has ended, to see my Dad and experience one of the most awesome wildlife spectacles on the planet – the explosion of breeding birds in temperate habitats.  At this time of year, evidence of breeding birds is everywhere, in nearly every available habitat.   It’s hard to find a location where you can’t hear males of at least a half-dozen species singing, particularly early in the morning.  In many habitats, the diversity is far higher.  Males are proclaiming and defending territory, and females are finding nest sites and building nests, sometimes with the assistance of their male partners, sometimes without.   At this time of year, everything birds are doing is related somehow to reproduction.

Northern Virginia in the spring - breeding birds are everywhere.

Northern Virginia in the spring – breeding birds are everywhere.

Access to good birding habitats in northern Virginia is a bit more problematic.  The entire northern Virginia/Washington D.C./southern Maryland area is one gigantic megalopolis, and remaining natural habitats are becoming more and more fragmented and isolated as development proceeds unabated.  For me, birding in northern Virginia requires an additional element of planning – travel between one site and another.  It can be horrendous.   Birding trips involving multiple locations require careful thought about when and how to move from one site to another to minimize the soul-numbing experience that is northern Virginia traffic.

Manassas National Battlefield Park is 5000+ acres of birding heaven, surrounded by the metastasizing growth of new development hell.  Two major commuter arteries, Routes 234 and 29-211, bisect the park.  The intersection of 234 and 29-211 is at the center of the park, and marks the location of Stone House, one of the most iconic landmarks of the park.   On weekday mornings, between about 6 and 10 a.m., this intersection becomes a huge parking lot, as backups a mile or more long build up.   Driving between one site and another within the park can become a nightmare.   So my tactics shift.  In the parlance of foraging ecology, I switch from a widely-ranging forager to a sit-and-wait predator.  My birding consists mostly of staying at one spot for much longer periods of time to avoid driving.   This approach probably leads me to see things I wouldn’t have seen using the run-and-gun approach.

The parking area at Battery Heights. The female great crested flycatcher was collecting nesting material from the area around the gate.

The parking area at Battery Heights. The female great crested flycatcher was collecting nesting material from the area around the gate.

Battery Heights is one of my favorite spots in the park.  This was an important Union artillery placement during the Battle of Second Manassas.  Today, a small, peripheral parking lot allows access to a grove of black walnuts, a couple of 12-pound Napoleon artillery pieces, and some signage, all surrounded by beautiful meadows and woodlands.  Infrequently visited by all but the most die-hard of battlefield enthusiasts, I can sit here for a half-hour or more (an eternity for me to stay in one spot) and just wait for cool shit to happen.  The walnut grove has turned up orchard and Baltimore orioles in the past; eastern bluebirds nest in the bores of the cannons, and chipping sparrows are nearly always singing nearby.  Robins nest in the area.   Eastern meadowlarks nest in the pasture.   The nearby woodlands are home to typical forest species – I occasionally hear scarlet tanagers and wood thrushes singing from those nearby woodlands.   In short, it’s a happening place for birds in spring.  Curiously, if I’m to visit this spot in the morning, I have to skirt the periphery of the park and approach it on 29-211 from the west.  Battery Heights is about 2 miles west of the aforementioned intersection of 234 and 29-211, which is one of the focal points of traffic hell during the morning drive.  If I were to drive directly through the park to reach Battery Heights from the east, I’d have to contend with a drive time of an hour or more.  To travel a couple of miles.

She was a bit suspicious of me, but she got over it. I talked it out with her.

She was a bit suspicious of me, but she got over it. I talked it out with her.

So there I was at Battery Heights on Saturday morning, chilling and grooving on the birds.  An orchard oriole was singing nearby.  I was concentrating on that bird, hoping for a photo op, when I noticed a great crested flycatcher swoop into the corner of the parking lot.  She perched briefly on a fence gate, and then dropped to the ground.  The area around the gate had been mowed recently, and there was an abundance of fine grass debris from the mowing.   She was collecting nesting material.   She snatched several bundles of fine grass until her beak was stuffed, then flew away.   Nothing that unusual or noteworthy there, though I don’t often see great crested flycatchers come down to the ground.  A few moments after the female flew in, though, I saw another flycatcher fly in behind her and land in the walnut tree above the spot where she was gathering nest material.  When she flew away, he followed.

This female digs her grass. Me too.

This female digs her grass. Me too.

Off she goes.

Off she goes.

She flew a couple hundred meters across the meadow towards the deciduous forest to the west, where the pair was nesting.  That seems like a long way to travel to gather some plant materials, but apparently her specific needs for nest-lining material were quite stringent.   Think about that for a moment – amidst all the different types of plant fibers and materials that are present in an eastern deciduous forest, she still made the decision to travel hundreds of meters across an open pasture, where she is certainly more vulnerable to predation by raptors like Cooper’s hawks.  That’s a bird with a very specific need to fulfill.

The pair flew several hundred meters across this meadow just to collect grass clippings.

The pair flew several hundred meters across this meadow just to collect grass clippings.

One of the comforting regularities of bird behavior is its regularity.  I kind of figured that she, and her mate, might return for more material, so I edged a little closer to the corner of the parking lot after the pair left.  Sure enough, a few minutes later, I saw her approaching across the pasture.  She swooped down to the gate again, eying me a bit longer than before.   The male followed a few seconds behind, and once again perched above her in the walnut.   I stayed in that spot for a half-hour or so, during which time the pair returned 5 more times to gather nesting material.   Like clockwork.  Nesting birds are fixated on their goal.   Never did the male come down to the ground or do anything tangible to aid the female in her work.  He just followed her around.  But why?

She always perched on the gate first to check me out before dropping to the ground.

She always perched on the gate first to check me out before dropping to the ground.

During the last couple of trips, she perched lower down on the gate on first approach.

During the last couple of trips, she perched lower down on the gate on first approach.

The twig is just the beginning.

The twig is just the beginning.

The entire load, twig and all.

The entire load, twig and all.

In retrospect, it isn’t so surprising that the female flycatcher was highly fixated on a specific type of nesting material.   One of the better-known peculiarities of great crested flycatcher nesting behavior is their compulsion to include a shed snake skin in the lining of their nest, which they build inside a tree cavity.   Decades ago, when I kept way too many rat snakes as pets, I placed a shed skin of a yellow rat snake in my front yard, draped over one of the dead snags near my bird feeder.   No more than an hour passed before I heard a pair of great crested flycatchers making a ruckus in the front yard.   As I watched from my living room, the female flew to the snag, surveyed the skin for a moment, fussed with it for a minute or two, then unwrapped it and flew away with it.  I was able to snag a couple of low-light photos through an open window.  More importantly, I thought, I had discovered a way to get phenomenal close-ups of great crested flycatchers during breeding season.  Simply bait them with a snake skin, yeah?   I’ve never observed that response to a snake skin again, though I’ve tried it numerous times.

The female flycatcher from my DeLand front yard claiming her snake skin. Scanned from a transparency.

The female flycatcher from my DeLand front yard claiming her snake skin. Scanned from a transparency.

Why a snake skin?   Some experimental evidence suggests that the presence of a snake skin deters visitation by flying squirrels, which can prey on the eggs and nestlings of the flycatchers.

So back to the question of the male’s role in all of these behaviors.  Basically, he does nothing other than accompany the female.  According to Cornell’s Birds of North America Online account of great crested flycatcher nesting behavior, males always follow the female around while she is building the nest, but never contribute directly to collecting materials or nest-building.  So what is he doing?

Feeding of offspring by parents constitutes both parental investment and parental care.

Feeding of offspring by parents constitutes both parental investment and parental care.

Reproductive biologists make a distinction between the forms of time/resource/energy inputs into reproduction, labeled as parental investment vs. parental care.  Parental investment refers to energy or resource expenditures by either parent that increase the chance of successfully reproducing, from the very beginning of the reproductive process (including formation of eggs and sperm) until the young have achieved complete independence.   Parental care is a particular form of parental investment, and refers to time/energy/resources expended after eggs are laid or offspring are born.  So the behaviors of both male and female in collecting nest material may be parental investment, but not parental care, since no eggs or hatchlings are yet present.  The female’s nest-building behaviors contribute directly to offspring success, so there’s no question that her behavior constitutes parental investment. Females provide more parental investment and parental care than males in most bird species.

Male great crested flycatchers - what are they good for?

Male great crested flycatchers – what are they good for?

Here’s the question that’s bugging me – is the male flycatcher’s behavior during collection of nesting material really parental investment?  The female’s behavior surely is, but do the male’s behaviors in any way contribute to nest building or the subsequent success of the offspring?

Eastern bluebirds are poster children for monogamy in birds, yet between 25-50% of nests have offspring sired by more than one male.

Eastern bluebirds are poster children for monogamy in birds, yet between 25-50% of nests have offspring sired by more than one male.

The alternative explanation is that the male is simply being selfish, protecting his own fitness.  One of the remarkable findings of avian reproductive biology over the last several decades is the ubiquity and surprisingly high frequency of infidelity between what we have traditionally called monogamous birds. Although their basic social unit during the breeding season is the pair, in many or most songbirds, both males and females regularly cheat on their mates.  In some species, up to 25% of the young in the population have been fathered by a male other than the bonded mate of their mother.   Apparently there are no data on the frequency of extra-pair copulations or extra-pair young in great crested flycatchers.

So male birds are generally very attentive towards their mates during the period up until the eggs are laid.  It takes only a minute or less for a female to pop a quickie with a neighboring male, so the bonded male must be constantly vigilant during this time.  So is that the only reason he’s following her around?  Stalking her, really.  A rather different interpretation than the idea that he is somehow helping and protecting her during her nest-building phase.  If the only purpose of his attendance is to prevent being cuckolded by his mate, then his activities aren’t really contributing to the success of the offspring at all.  And what he is doing doesn’t constitute parental investment.

Loving, protective mate or jealous stalker?  You be the judge.

CEWA_02212016-07_620 COC

The nomads return

CEWA_20120215-135_Stetson

February 28, 2016

The idea of a nomadic lifestyle has great appeal to me, which is especially surprising considering what a homebody I am.  On the infrequent occasions I take trips requiring more than a day, they are fully planned and orchestrated with all the precision an anal-retentive like me can muster.   Still, the idea of packing a minimum of gear into a beat-up car and taking off on a whim across the country has long been a fantasy, albeit one I’m sure I’ll never attempt to fulfill.

Yellow-rumped warblers are able to winter further north than most warblers, in part due to their ability to feed on the fruits of waxmyrtle and digest the waxy coating as well as the pulp.

Yellow-rumped warblers are able to winter further north than most warblers, in part due to their ability to feed on the fruits of waxmyrtle and digest the waxy coating as well as the pulp.

Among North American birds, perhaps the ultimate nomadic species is the cedar waxwing.  So many aspects of the lifestyle and habits of these thoroughly charming birds are unique, and most are directly or indirectly related to the fact that it is one of the relatively few bird species on the continent that can truly be called a frugivore.  Sure, lots of wannabes will take fruit opportunistically at times, sometimes relying heavily on it for their caloric needs for short to moderate lengths of time.  The ability of tree swallows and yellow-rumped warblers to winter in great numbers farther north than other members of their clans, which mostly depend on insects for the greatest portion of their provender, has been attributed in part to their ability to subsist largely on the fruits of winter-fruiting shrubs such as bayberry.  Both species have the unusual ability to digest the waxy coating of bayberry and waxmyrtle fruits, allowing them to survive periods when insects are hard to find.

Cedar waxwings in the pine flatwoods of Heart Island, feeding on the fruits of Ilex glabra, or inkberry.

Cedar waxwings in the pine flatwoods of Heart Island, feeding on the fruits of Ilex glabra, or inkberry.

Cedar waxwings, and the other two species of waxwing (Bohemian and Japanese) which collectively make up the entire family Bombycillidae, are true frugivores, depending almost entirely on fruit for most of the year.  They do switch to a partial reliance on other foods in the spring and summer; in May, they rely heavily on flower buds, of all things, and later in the summer when they begin feeding nestlings they take a greater proportion of insects, necessary to provide the proteins lacking in most fruits.

The quest for fruits has led cedar waxwings to evolve a peripatetic lifestyle for all but those few months of the year when they must drop anchor to nest.   Consequently, for bird photographers, and birders in general, they are a challenge to find at will, and a delight to see and photograph when found.   As winter visitors to Florida, they are guaranteed to show up at some time or another between about October and May, but exactly when and where that will be is subject to a great deal of whimsy.   For a bird photographer to state with any sense of confidence that I’m going to photograph waxwings today is a proclamation as foolish as planning to win a Powerball drawing.  Unless he or she happens to be looking at them at that very moment.   Here today, gone an hour later.

Waxwings in northern Virginia, on their breeding ground, feeding on mulberry, Morus rubra.

Waxwings in northern Virginia, on their breeding ground, feeding on mulberry, Morus rubra.

Ornithologists concerned with classifying patterns of bird movement express hesitation at calling waxwings migrant, though they do show regular patterns of southward and northward movement at a broad scale, at the appropriate times of year.   Those movements, though, do not begin to approach the level of regularity and predictability of most true migrants.   They show relatively low levels of philopatry in the breeding season; in other words, unlike many birds, they don’t tend to return to the same breeding areas year after year, and during the winter their movements seem to be completely irregular and unpredictable.   Both of these characteristics are related to their reliance on fruit, which is itself somewhat unpredictable in time and space, and once found, subject to rapid depletion once big flocks of frugivorous birds discover it.

A cedar waxwing pair passing a piece of fruit back and forth, part of their courtship and pair-bonding ritual.

A cedar waxwing pair passing a piece of fruit back and forth, part of their courtship and pair-bonding ritual.

The ability of big flocks to rapidly consume most or all of the fruit in an area is one of the most appealing aspects of their behavior.  Watching a writhing, swirling mass of lovely pastel-colored birds attack a mass-fruiting holly or cherry tree and pick it clean within a few minutes is an amazing sight.  Part of the appeal of that behavior is the furious and fanatical way they conduct their feeding frenzies; birds are constantly moving into and out of the fruiting tree, plucking a few fruits and quickly departing to perch nearby before the next foray.   The result is often a maelstrom of activity that can be over and done with in the blink of an eye.   Followed by the departure of the flock to parts unknown, seeking their next meal.

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Trees full of large flocks of waxwings are one of the most welcome sights of winter.

Waxwings have been less abundant this season than my notoriously untrustworthy memory suggests they usually are.  Some winters between January and February, they descend on DeLand in huge numbers, with flocks numbering in the thousands.  For the few days or weeks they are around, it’s hard to miss the big roving groups bopping around town devouring every fruit in sight.  One morning they might be devouring the fruits of sabal palms in the parking lot of the Publix where I shop, the next at a yaupon hedgerow near a strip mall.   A few years ago, huge flocks were on the Stetson campus for several days in a row; one morning on my way to my office, a flock of hundreds was feeding and drinking around the Gillespie museum, and I spent a delirious hour or so photographing them.    Students in my Intro Biology II class were subjected to 15 minutes of my rantings about and photographs of the waxwings that morning, exhorting them to be on the lookout for these wonderful wanderers over the next few days.  I have no idea whether that rant led anyone in that class to give even a second thought about waxwings afterwards; probably to them the most salient fact about my waxwing rhapsody was that it wouldn’t be covered on the next test.   Another morning, as I was driving through the new development next to the one I had just moved into, I photographed a small flock of waxwings beefing with a group of robins over a few drops of water beaded atop an electrical junction box.   To photograph waxwings requires eternal vigilance.

Waxwings and robins competing for space and a few droplets of water atop an electrical junction box.

Waxwings and robins competing for space and a few droplets of water atop an electrical junction box.

Congregation of waxwings at a sidewalk puddle on the Stetson campus.

Congregation of waxwings at a sidewalk puddle on the Stetson campus.

Last Sunday afternoon I was drifting in and out of a mid-afternoon stupor when I was awakened by the wick calls of a couple of robins in the backyard.  Robins shifted into their urban phase several weeks ago, and have been fairly common in the neighborhood and around DeLand.  The presence of flocks of robins indicates the possibility of waxwings in the area – the two often travel together, and feed together at mass-fruiting plants.  I had only seen waxwings in my neighborhood a couple of times so far, though, and none had been feeding.  I have several large wild cherry trees with large fruit crops I had been keeping my eye on, and though I had seen robins feeding at them several times, they were never accompanied by waxwings.   Soon after I heard the robin calls, one of them flew down to the birdbath, soon to be joined by another.  And then I heard the high, quavering seeee calls of a couple of waxwings, and I was instantly wide awake.  I happened to have my camera with big bird lens on the couch beside me, and was ecstatic when a pair of waxwings joined the robins at the birdbath.  I fired off a couple of record shots, and then the birds spooked and took off.   Soon they were back, accompanied by a half-dozen or more additional waxwings, and they and the robins spent the next three or four minutes bathing and occasionally sparring for position.  I eased out the back door onto the enclosed patio, and was shooting nearly non-stop the entire time they were there.   Hoping like hell that all the settings were right, because I had no time to stop and chimp my shots to ensure I wasn’t making some major bonehead mistake.

The robin at the birdbath alerted me to the possibility of waxwings.

The robin at the birdbath alerted me to the possibility of waxwings.

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Though they have their occasional spats, peaceful coexistence between the robins and waxwings is possible.

Though they have their occasional spats, peaceful coexistence between the robins and waxwings is possible.

Soon, though, something signaled the waxwings it was time to move on, and they departed en masse, trilling as they winged away.  I haven’t seen them in the neighborhood since, and may not again this winter.  And that’s okay.  They graced me with their presence and gave me reasonable photo opportunities for a few minutes, and for that I’m thankful.  See you next year, my friends.  I hope.

Nemesis no more

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June 15, 2015

Every serious bird photographer who has been at it for a while has a nemesis bird or three. There’s a progression for the obsessed bird photographer – first you knock out all the easy stuff. You know, feeder birds, extremely common and cooperative stuff like yellow-rumped warblers, turkey vultures, ring-billed gulls, and so on. At some point, for many of us, then the compulsion turns into a quest to photograph all the birds of the region you spend most of your time in. An unattainable goal for most, but a tangible target nonetheless. Gradually the library of images grows, until you have acceptable images of most of the typical species. It’s a moving target, though; one problem is that the definition of acceptable is constantly changing as your proficiency increases (hopefully). So while your biggest pleasure is photographing a species that you have no images of, you’re constantly trying to upgrade the quality of the images of those species already photographed. And so it goes. You accept that the very rare or elusive species are distant dreams at best, but every now and again that improbable event occurs and you actually add one or two of those to your collection of bird images. Why do we do it? That’s a whole other question I’m not about to try and tackle; I really don’t understand it myself. It does take on aspects of mental illness after a while, though. How many hundreds of images of northern parulas and great blue herons do you really need? The only answer I’ve ever arrived at is more.

As beautiful as they are, some birds, like northern parulas, are just too easy to photograph to be a real challenge.

As beautiful as they are, some birds, like northern parulas, are just too easy to photograph to be a real challenge.

More vexing than the rare species though are the nemesis birds. Those are the species that aren’t particularly uncommon or hard to find, and of which you can find thousands of high-quality images on-line, yet they somehow elude your best efforts to add them to your list. The degree of consternation inflicted by these recalcitrant bastards is directly related to how long you have pursued them. In some cases it may be decades.

I have dozens of images  of the larger American bittern that I'm pretty happy with;  least bitterns are a different story.

I have dozens of images of the larger American bittern that I’m pretty happy with; least bitterns are a different story.

For me, one of the nemesis birds that has been at the top of my list for the decades I’ve lived in Florida is the least bittern. These elegant little birds, the smallest of the North American herons, are widespread as breeding birds in the ubiquitous wetlands of Florida. They occur as far north as Virginia, where I cut my birding and bird photography teeth, but I never saw them there. But in Florida, they are not difficult at all to find, or uncommon. Breeding densities as high as 15 pairs per hectare have been recorded. They do tend towards the skulky end of the behavioral continuum, though, which combined with their small size (12-14”, not much larger than a blue jay), can make them a bit of a challenge to photograph. But seeing them – hell, I see them all the time during the breeding season in the appropriate habitat. During the 7 years I did weekly bird censuses at Emeralda Marsh Conservation Area in Eustis, which contains lots of good breeding habitat, I saw them regularly between mid-March, when most return from their winter home, and mid-October, when most of them have departed. During mid-summer, I would often see or hear 5 or more of these charming little waders on each census. Their departure each year, in which I once again failed to obtain a decent photo, always brought a bit of anguish, and a bit of hope that next year would be the one. An occasional oddball individual will overwinter in central Florida, but for the most part they are the typical birds of summer. By which I mean Florida summer, which runs from about March to October.So I never really entertained any illusions of photographing one outside of the breeding season.

Seasonal abundance of least bitterns at Emeralda Marsh Conservation Area, near Eustis FL.

Seasonal abundance of least bitterns at Emeralda Marsh Conservation Area, near Eustis FL.

This is no great blue heron, posing in every roadside ditch for any yokel with a point-and-shoot. (No offense to the yokels with point-and-shoots out there.) You have to go looking for them, and then you have to find one close enough (which is pretty damned close for a bird that small) and exposed enough for a decent photo. Needless to say, that particular set of conditions eluded me for so long. Oh, sure, I got photo ops on occasion. I have several dozen transparencies (also called slides, for those digital natives unfamiliar with the concept of film) with recognizable least bitterns on them. But in all, they are small in the frame, and none of them captured the essence of least bittern.

Seriously, any twit with a pinhole camera can get stunning closeups of great blue herons in Florida.  Which is not to say that I don't still photograph them on occasion.

Seriously, any twit with a pinhole camera can get stunning closeups of great blue herons in Florida. Which is not to say that I don’t still photograph them on occasion. What can I say – I’m a high-tech twit.

These are amazing little birds to watch, if one is fortunate enough to see one foraging for any period of time. On the continuum of foraging strategies of herons and egrets, ranging from the nearly immobile ambush foragers like great blues to the maniacal pursuit foragers like reddish egrets, least bitterns are somewhere in the middle. They can be frozen for extended periods, intensely peering at a couple of square inches of habitat until a prey item comes into range, but they can also be relatively active, changing perches every minute or two until they find the right spot. Acrobatic little fuckers they are as well, hanging upside down from a narrow perch above the water, extending their telescoping necks in an instant to snag the dullard mosquitofish that fails to notice this pendulous beauty.

That's some neck serious neck extension.

That’s some neck serious neck extension.

So yeah, I have a handful of old, mediocre images of least bitterns, a couple of which I thought were pretty decent at the time I took them. The advent of the interwebs totally recalibrated my concept of what constitutes a decent image, though. Once I began seeing the high-quality images so many other photogs were able to obtain of this handsome little heron, my evaluation of my own images plummeted. One of my favorite images, at the time, was of a recently fledged youngster sitting on his haunches in the middle of Airstrip Road, surrounded by shellrock, with a few wispy tufts of down feathers still remaining on his adorable little noggin. But this slide, like all my others, failed to meet one of my prime criteria for a good bird shot – you need a level of resolution allowing discrimination of barbs of individual feathers. My old slides all failed that test.

One of the best of my least bittern shots from the film era.  Lacking in so many ways.

One of the best of my least bittern shots from the film era. Lacking in so many ways.

My favorite film image of a least bittern - a slightly out-of-place, befuddled looking youngun.

My favorite film image of a least bittern – a slightly out-of-place, befuddled looking youngun.

Even after I went digital, which makes bird photography an order of magnitude (at least) easier than the primitive film technology, good least bittern images still eluded me. I made a couple of trips during the breeding season to the celebrated Viera Wetlands in Brevard County, a site from which I had seen dozens of superb least bittern photographs posted on-line. I saw them there, but never got anything approaching the type of image I had in my mind.

I was moderately satisfied with this "in-habitat" shot of a least bittern from Viera Wetlands, but it wasn't really what I was hoping for.

I was moderately satisfied with this “in-habitat” shot of a least bittern from Viera Wetlands, but it wasn’t really what I was hoping for.

The closest I had come to a satisfactory close-up of a least bittern prior to yesterday's outing.

The closest I had come to a satisfactory close-up of a least bittern prior to yesterday’s outing, also from Viera Wetlands.

So I’m pleased as punch, as the happy warrior Hubert H. used to say, to report that my quest for decent least bittern photos has turned the corner. I’m also happy to report that this happened at my new favorite bird photography site, the Lake Apopka Restoration Area wildlife drive. On my first visit a few weeks ago, I thought this magnificent site should be full of least bitterns, but didn’t actually see or hear any until my second or third visit. A couple of weeks ago I actually got some marginally acceptable ops with a least bittern perched in a willow tree. The photos were by far better than anything I had previously, but the light was less than optimal (a totally overcast morning, the bird strongly backlit by a featureless white sky), and it was a bit too distant to reveal the kind of plumage details I consider requisite for a good bird photo.

Least bittern in a willow, from Lake Apopka Restoration Area.

Least bittern in a willow, from Lake Apopka Restoration Area.

Show me what you can do with that neck.

Show me what you can do with that neck.

Yesterday, my chakras aligned. The bird gods smiled. I got lucky. Interpret it as you see fit. It was a sunny morning, bird activity was everywhere along the wildlife drive, and around 8:00 a.m. while the morning light was still sweet and rich, I spotted a least bittern feeding from some dead stems of some emergent woody plant in a shallow impoundment. And it was relatively close to the road. Somewhat incredulously, I slow-rolled towards the little dude, expecting it to bolt into deep cover long before I was in photo range. But he didn’t. I slowly pulled up to where he was feeding, with the light coming from directly behind me (point your shadow at the bird, says the bird photog guru Artie Morris), and he cared not a whit. Heart pounding, adrenaline pumping, I feverishly began photographing. After a minute or two, the least beast decided to move, flying to a new perch 30 or so yards behind me. But still close to the road. I backed up slowly, and once again he stayed for a few moments, allowing a few more shots as he moved from perch to perch before finally disappearing into dense cover.

The first excellent photo op of the morning.

The first excellent photo op of the morning.

I particularly liked all the carnivorous bladderwort plants in flower below this leastie.

I particularly liked all the carnivorous bladderwort plants in flower below this leastie.

Full neck extension.

Full neck extension.

One parting over-the-shoulder look before he disappeared into the veg.

One parting over-the-shoulder look before he disappeared into the veg.

I was totally juiced. It’s fair to say that if I hadn’t taken another photo or seen another bird that morning, I would have considered it a morning very well-spent. As I drove on along the wildlife drive, I was savoring the moment when I could look at those images on the big screen and begin editing them. There’s something incredibly rewarding about capturing even one series of decent images relatively early in the morning; it doesn’t really matter what the rest of the day brings. You know you already have some images you’re going to be pleased with. Of course there’s always that bit of the neurotic in me that begins the second-guessing game – what if I did something wrong, or missed critical focus? Even after chimping the images like a demented fool my fears are never completely allayed. You can only judge image quality so far by viewing them on the LCD screen of the camera. You have to download them and view them large to really make an accurate assessment.

Cooperative least bittern number two.  Even closer than the first.

Cooperative least bittern number two, perched on one leg, with the other tucked up into his belly feathers. Even closer than the first.

So I was a pretty contented dude at that point. But that wasn’t to be my only bittern buzz of the day. Not more than 15 minutes later, I spotted another, sitting completely exposed on a dead branch, in perfect front light. Even closer than the first. And once again, I was amazed as I slowly rolled up on him and he sat perfectly still. I shot this guy for 4-5 minutes as he mostly did nothing other than check me out occasionally. At one point he dropped the foot that he had tucked into his belly feathers, turned around, hunched forward, and expanded his throat and chest as he began calling with the sweet cuckoo-like call that is the easiest way to detect the presence of these tiny ardeids. I was in a state of absolute euphoria as I filled a memory card. Hundreds of images varying only in the slightest degree, the vast majority of which would never be seen by anyone like me. But what did I care? A nemesis bird had been forever removed from the list.

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A vertical shot, still on one leg. When you’ve got a bird posing for you like this, it’s hard not to go batshit crazy.

 

Eyeballing me under the chin, a charming behavior of the least bittern.

Eyeballing me under the chin, a charming behavior of the least bittern.

Turned around, throat puffed out and calling.  One of the last shots in the series.

Turned around, throat puffed out and calling. One of the last shots in the series.

Can the crested caracara be far behind?

Image Gallery: Return to Lake Apopka Restoration Area

 

The yellow flowers blanketing this pool are bladderworts, Utricularia sp., a carnivorous plant.  I've never seen a concentration of bladderwort like this.

The yellow flowers blanketing this pool are bladderworts, Utricularia sp., a carnivorous plant. I’ve never seen a concentration of bladderwort like this.

May 18, 2015

All images are linked to larger versions.

I couldn’t help myself.  I visited the new wildlife drive at Lake Apopka Restoration Area again yesterday, and though the light was miserable for photography for the first couple of hours, the wildlife was there.  Here are some of my favorite shots from the morning.

Recently fledged great blue heron.

Recently fledged great blue heron.

Bullfrog feeding a mosquito.

Bullfrog feeding a mosquito.  Look closely under his right eye.

Common moorhens and their broods were once again one of the most entertaining sights.

Common gallinules and their broods were once again one of the most entertaining sights.

Sorry, bro, you cannot pass.

Sorry, bro, you cannot pass.

This osprey was sitting atop a leaning pole trying to eat his fish.

This osprey was sitting atop a leaning pole trying to eat her fish.

She was repeatedly harangued by this boat-tailed grackle, who bum rushed her several times.

She was repeatedly harangued by this boat-tailed grackle, who bum rushed her several times.

Why?  Eventually the osprey moved on, and the grackle took top spot and cleaned up on the fish scraps.

Why? Eventually the osprey moved on, and the grackle took top spot and cleaned up on the fish scraps.

 

Least bittern in the willows.  You don't appreciate how long their neck is until they stick it out.

Least bittern in the willows. You don’t appreciate how long their neck is until they stick it out.

A more typical view of a least bittern.

A more typical view of a least bittern.

Green herons were abundant, but very shy.  This one allowed me one shot before taking off.

Green herons were abundant, but very shy. This one allowed me one shot before taking off.

A juvenile little blue heron showing high breeding colors in the cere and base of the bill.  Yearling birds in juvenile plumage will sometimes breed in this species.

A juvenile little blue heron showing high breeding colors in the cere and base of the bill. Yearling birds in juvenile plumage will sometimes breed in this species.

Not a bad day for herps.  This Florida green watersnake (Nerodia floridana) was basking in the dead cattails as the sun struggled to make an appearance.

Not a bad day for herps. This Florida green watersnake (Nerodia floridana) was basking in the dead cattails as the sun struggled to make an appearance.

That's one chilled out baby gator.

That’s one chilled out baby gator.

A big female soft-shelled turtle (Apalone ferox) mucking around in the shallows.

A big female soft-shelled turtle (Apalone ferox) mucking around in the shallows.

Pig frog (Lithobates grylio) surrounded by several floating aquatic plants, including Lemna sp., (duckweed),   Salvinia minima (water spangles), and Azolla filiculoides (American waterfern; not a fern).

Pig frog (Lithobates grylio) surrounded by several floating aquatic plants, including Lemna sp., (duckweed), Salvinia minima (water spangles), and Azolla filiculoides (American waterfern; not a fern).

Eastern kingbird.  I don't see this species often in central Florida except as a migrant in passage.  This bird is probably a breeder.

Eastern kingbird. I don’t see this species often in central Florida except as a migrant in passage. This bird is probably a breeder.

I saw a half-dozen or so limpkins.

I saw a half-dozen or so limpkins.

These two great blue herons were arguing over territorial rights, using the  head up-wing droop posture that says get the hell out of my space.

These two great blue herons were arguing over territorial rights, using the head up-wing droop posture that says get the hell out of my space.

By mid-day, it was getting quite toasty.  Barn swallows were basking on the hot shell rock roads, overheating to the point that they were panting to cool down.  Why?  Probably to kill ectoparasites with the heat load.

By mid-day, it was getting quite toasty. Barn swallows were basking on the hot shell rock roads, overheating to the point that they were panting to cool down. Why? Probably to kill ectoparasites with the heat load.

Anhinga performing gular flutter, a heat-dissipating behavior.

Anhinga performing gular flutter, a heat-dissipating behavior.

 

A splendid morning in the wetlands

Black-necked stilt snags a mosquitofish

Black-necked stilt snags a mosquitofish

Click on any image to see a larger version.

May 10, 2015

On Friday I visited the Lake Apopka Restoration Area’s newly opened 11-mile North Shore wildlife drive for the first time. To say that I was impressed with the wildlife viewing opportunities there would be a massive understatement. This area will surely become one of my regular destinations for natural historizing and photography in coming years.

When I was a graduate student at the University of Florida in the 80’s, I remember hearing of the incredible birding opportunities in late summer at the Zellwood muck farms. I never made the drive to check the area out. I should have. My first visit to the north shore area of Lake Apopka came in the fall of 1998, when I was checking out potential field trip sites for the Ornithology class I was teaching that fall at Stetson. From DeLand, it’s less than an hour’s drive, mostly through bucolic mixed agricultural habitat in Seminole County. I distinctly remember driving down one of the shell rock roads, surrounded on both sides by browned, fallow vegetation with little evidence of the legendary concentrations of migratory birds I had come to see. A couple of times I saw small groups of aquatic birds, including some waders and terns, flying past me towards the west. Encouraging. Then I topped a small rise that allowed an overview of one of the flooded fields that acted as the great bird attractors, and I nearly ran off the road at the stunning sight of hundreds of acres of shallow water fields teeming with aquatic birds of every stripe. Tons of waders, including hundreds of great blue herons, white pelicans, other egrets and herons, wood storks, and a panoply of smaller birds including shorebirds, terns, anhingas… I was ecstatic. I made several visits to the area in the next couple of weeks, and then the St. Johns Water Management District closed the whole area to public access. Dead birds started showing up by the hundreds.

Most of the habitat in the Lake Apopka Restoration Area is highly disturbed, consisting of former agricultural fields that are converting back to a variety of  marsh habitats.

Most of the habitat in the Lake Apopka Restoration Area is highly disturbed, consisting of former agricultural fields that are converting back to a variety of marsh habitats.

The vast wetlands fringing Lake Apopka, a 30,000-acre lake that is Florida’s fourth largest, had been heavily farmed since the 40’s, and the “muck farming” operations devastated the water quality in Lake Apopka and its surrounding highly modified wetlands. These farming operations left behind miles of levees, roads, canals and pumping systems to move lake water onto and off of the agricultural fields that had been formed by draining the natural wetlands. After spending nearly $100 million between 1996 and 1999 to buy out about 13,000 acres of former farmland, the St Johns River Water Management District began major restoration efforts in the mid-90’s. Restoration plans for the area featured a 760-acre flow-way designed to circulate highly eutrophic lake water through restored wetlands in order to filter out excess nutrients and pollutants, and also included the flooding of large tracts of farmland in the fall of 1998 in the Zellwood farming district. The Zellwood muck farms were legendary for years among Florida birders for their late summer and fall concentrations of shorebirds. Large numbers of sandpipers, plovers, gulls, terns and other aquatic birds would congregate in the temporarily flooded fields in late summer to feed and prepare for the rest of their migration. During the farming era, however, these fields were drained and planted with winter crops by November, and whatever birds remained in the area moved on.

Canals and water control structures permeate Lake Apopka Restoration Area.

Canals and water control structures permeate Lake Apopka Restoration Area.

In fall of 1998, the management plans for the area called for prolonged flooding of some of these fields, and the response by the avifauna was incredible. Between August 1998 and February 1999, local bird groups and district scientists documented over 111,000 individual birds using an 8000-acre area. Flocks of tens of thousands of teal, diving ducks, and American coots were present at times. Beginning in November, however, dead birds began to appear on the site. White Pelicans were the hardest hit; at one time, the white pelican flock at Zellwood numbered over 4000, believed to be nearly half of Florida’s wintering population of these huge, lumbering birds. By February of 1999, nearly 500 bird deaths had been recorded on site, and another 500 or so dead birds, mostly white pelicans, were found throughout Florida, and were suspected to have originated from the Zellwood area. Also affected were smaller numbers of wood storks, an endangered species, along with great egrets and ring-billed gulls. I remember watching a juvenile wood stork at Lake Woodruff National Wildlife Refuge in DeLeon Springs for several days in a row during January 1999, some 40 miles away from Lake Apopka. That bird moved fairly slowly, was quite tame, and stayed in the same restricted area for the entire time I observed it. Nearly a week later, I found the carcass of a wood stork near where I had seen that curiously behaving bird. I still have the skull on a shelf in my office.In retrospect, I suspect that it was also a Zellwood bird.

Ospreys were abundant on this lovely May morning, especially in the parts of the drive closer to Lake Apopka.

Ospreys were abundant on this lovely May morning, especially in the parts of the drive closer to Lake Apopka.

The catastrophic bird mortality took everyone involved with the project by surprise. Although extensive sampling of the acquired lands was done before flooding to determine if there were any contamination hazards, the assays failed to turn up anything that looked like a threat to the health of the birds. In February 1999, the flooded fields were drained to encourage the birds to move elsewhere, and extensive soil and water sampling was performed, along with necropsies of many of the dead birds to attempt to determine the source of mortality. A period of uncertainty and debate about the source of the bird kill ensued, during which a variety of hypotheses, including pesticide contamination and epidemic outbreaks of avian cholera and Newcastle’s disease, were proffered. Eventually, acute toxicity due to exposure to multiple pesticides (toxaphene, Dieldrin, DDT) was identified as the most likely cause, and the restoration/remediation plans for the Apopka North Shore Restoration project were modified accordingly. Apparently, a concentrated “hot spot” of discarded pesticides on a restricted area of the north shore property was responsible for all of the problems. Amazingly, the pesticides involved had been banned and out of use for 10-30 years.

This boat-tailed grackle was engaged in "gaping behavior".  They insert their beak into some substrate and open it to push aside obstructions.  Many icterids use this behavior to find soil invertebrates, but this male was using it to open a little hole in the duckweed through which he could peer down into the water.

This boat-tailed grackle was engaged in “gaping behavior”. They insert their beak into some substrate and open it to push aside obstructions. Many icterids use this behavior to find soil invertebrates, but this male was using it to open a little hole in the duckweed through which he could peer down into the water.

The target?  Snails.  He deftly pulled them out of the shell and enjoyed fine dining even without the garlic butter.

The target? Snails. He deftly pulled them out of the shell and enjoyed fine dining even without the garlic butter.

For the next decade, as mitigation and clean-up efforts proceeded, most of the North Shore area of Lake Apopka was mostly off-limits to the public. One of the mitigation techniques used to deal with the elevated concentrations of organochlorine pesticides and excessive nutrients that had accumulated from decades of farming was a method called soil inversion. Modified agricultural equipment was used to plow down to a meter or more into the heavily contaminated top layer of soil and flip it over, replacing it with deeper layers of clean soil.

The vegetational composition of the wetland habitats is highly variable.  Many areas are dominated by cattails, usually an indicator of high nutrient levels (eutrophication).

The vegetational composition of the wetland habitats is highly variable. Many areas are dominated by cattails, usually an indicator of high nutrient levels (eutrophication).

Restricted access to the public ended in 2014, when the SJRWMD began opening some of these north shore properties, easily accessible due to the extensive networks of diked roads, to the public for hiking and biking. The North Shore Wildlife Drive opened on Friday, May 1. It is open from sunrise to a half-hour before sunset on Fridays, Saturdays and Sundays year-round.

Waders of all types were common, including great and snowy egrets, great blue, little blue, tricolored and green herons, and a few black-crowned night herons.  This bird is an immature.

Waders of all types were common, including great and snowy egrets, great blue, little blue, tricolored and green herons, and a few black-crowned night herons. This bird is an immature.

Little blue herons and green herons were probably the two most common waders I saw.

Little blue herons and green herons were probably the two most common waders I saw.

Green herons were omnipresent, but a bit skittish.  Not many photo ops for these shy guys.

Green herons were omnipresent, but a bit skittish. Not many photo ops for these shy guys.

I wasn’t expecting huge numbers of birds or great diversity on this visit; wintering birds have largely left the state, and the passage of transient migrants is rapidly winding down. It’s that time of year for Florida birders when diversity is plunging to its summer nadir. Still, I was hoping there might be a few bobolinks around, and perhaps some other lingering migrants. I wasn’t disappointed. Almost as soon as I entered the drive, I heard, then saw a small flock of bobolinks in the marshes north of the drive. Too distant for photography, but it didn’t matter. Much. I love seeing and hearing bobolinks, anytime, anywhere, at any distance. The first stretch of the drive heads due west, so the sun was directly at my back and the habitat on either side was strongly side-lit. Not the best conditions for bird photography, but still I was impressed by the dozens of herons, egrets, ibis, limpkins, and other aquatic species foraging in the canal paralleling the drive. And the marshes were full of singing icterids on territory – red-winged blackbirds and boat-tailed grackles. So I was a little bummed out by the lack of photo opportunities in the first couple of miles of the drive, but there was so much bird life around that it didn’t feel right to be disappointed. In addition to the waders in the canals, several black-bellied whistling ducks and a couple of mottled ducks did flyovers, along with lots of waders. Barn swallows were coursing low over the marshes throughout the morning.

Common gallinules were abundant, including numerous pairs tending to their broods of newly hatched fuzzballs.

Common gallinules were abundant, including numerous pairs tending to their broods of newly hatched fuzzballs.

This half-grown juvenile common gallinule was all by his lonesome.  Perhaps the only surviving member of his brood.

This half-grown juvenile common gallinule was all by his lonesome. Perhaps the only surviving member of his brood.

Common gallinules are attentive parents.  This one was teaching her youngster how to preen.

Common gallinules are attentive parents. This one was teaching her youngster how to preen.

How do I look, Mom?

How do I look, Mom?

Feeding the babies.

Feeding the babies.

About two miles in, the drive reaches the shore of Lake Apopka and a large, historic pump house remaining from the agricultural period. On a small, drying pond near the pump house, I found a black-necked stilt, solitary sandpiper, and least sandpiper feeding in the shallow water and muddy shoreline, directly front-lit by gorgeous early morning light. As I spent the next 20 minutes or so burning up my memory cards on these photogenic birds, my slight dudgeon lifted. This is what I had come for.

Black-necked stilts are very active foragers, frequently submerging their entire head searching for prey.

Black-necked stilts are very active foragers, frequently submerging their entire head searching for prey.

Like this.

Like this.

Got one.

Got one.

The rest of the morning followed suit. Though the birds were mostly breeding residents, it mattered not. Common gallinules, various egrets and herons, blackbirds, including a couple more small flocks of bobolinks, barn swallows (along with a few tree swallows in one flock), and other birds were everywhere. In one of the canals paralleling the drive, I was shocked by the huge numbers of big frogs half-submerged in duckweed and Salvinia, occasionally making short leaps to capture prey. Both bullfrogs and pig frogs were calling, which was somewhat surprising to me. I had always thought of those two species as ecological equivalents that didn’t normally co-occur. I don’t know where I picked up that bit of dubious knowledge, but clearly it doesn’t apply to the big Lithobates (could it be true that this horrendous genus is about to be decommissioned and the members of this genus placed back into Rana, where they belong? Joy.) frogs of the restoration area.

While shorebirds weren't particularly diverse, and I only saw a few individuals of any species, it was still nice to see killdeer, stilts, spotted and solitary sandpipers, and several of these tiny little least sandpipers.

While shorebirds weren’t particularly diverse, and I only saw a few individuals of any species, it was still nice to see killdeer, stilts, spotted and solitary sandpipers, and several of these tiny little least sandpipers.

Solitary sandpiper

Solitary sandpiper

Solitary and least sandpiper

Solitary and least sandpiper

With all of those frogs, I figured there must be tons of snakes to prey on them, but I saw no water snakes or other aquatic serpents. A couple of black racers crossing the road were the only snakes I saw on this morning, but I’ve got to think the frog-eating aquatic snakes are there somewhere. Another time.

Bullfrog (Lithobates or Rana catesbeianus)

Bullfrog (Lithobates or Rana catesbeianus)

Pig frog (Lithobates or Rana grylio)

Pig frog (Lithobates or Rana grylio)

The bullfrogs were freaking thick!

The bullfrogs were freaking thick!

Besides the frogs, the other herps seen included lots of gators, a couple of black racers, and this cute little striped mud turtle (Kinosternon bauri) who looks like she just finished laying eggs.

Besides the frogs, the other herps seen included lots of gators, a couple of black racers, and this cute little striped mud turtle (Kinosternon bauri) who looks like she just finished laying eggs.

And there certainly will be other times. I can barely wait until August, when the vanguard of fall migrants will begin to appear in numbers. I’m particularly excited about the potential for big numbers of yellow warblers, which I haven’t seen aside from an occasional lone individual or two since I stopped doing bird censuses at Emeralda Marsh Conservation Area. In August and September I sometimes found hundreds of yellow warblers a day in the willow thickets along the levee roads. There’s an abundance of similar habitat along the wildlife drive at Lake Apopka.

The best part of the day? In the 4 hours I spent there, I saw only one other car. I wish it would stay that way, but I know it won’t. The area is too amazing to remain a secret for long.

A quick trip to the parking lot of the North Shore trailhead at the end of Duda Rd. produced this lovely indigo bunting.

A quick trip to the parking lot of the North Shore trailhead at the end of Duda Rd. produced this lovely indigo bunting.

For more information about the North Shore Wildlife Drive, go to http://www.sjrwmd.com/recreationguide/lakeapopka/

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.