Category Archives: Blog

Ratty birds

August 7, 2013

Two things strike me about this time every year when I go out to look at or photograph birds.  The first is that this is the worst time of year to watch birds in Florida.  Diversity is at the low point in its annual cycle, though that is changing every day as new migrants move into the state.  The second is that many passerines look pretty miserable at this time of year.

Carolina wren

Carolina wren

The reason for the first phenomenon, the low diversity of breeding birds in Florida, is a bit of a mystery.   The reason for the second is a little clearer.  Many birds are in the midst of their post-nuptial molt, in which they replace the plumage they wore for their reproductive activities for a new set of feathers that will last them until next year’s breeding season.  While absolutely necessary, molt isn’t a pretty thing.

Molt is quite a complicated phenomenon.  Among different species there is tremendous diversity in the patterns and timing of molt, and the resulting plumages.  In some groups of birds, like gulls, it can take several years for an individual to acquire the definitive adult plumage.  Each of the immature plumages can differ subtly from the others, making identification a challenge.  Even in smaller birds with more accelerated life cycles, which may molt into their first alternate (breeding) plumage at a little less than one year of age, there are major differences in the timing of molt between species, and even between individuals of the same species.  Below, for example, is a Carolina wren I photographed today that was traveling with the molting individual above.

Carolina wren

Carolina wren

The wren above is likely a young bird, hatched earlier in the summer.  The gape, a bit of soft tissue  looking something like lips, is visible at the base of the bill.  The color of the breast is a little paler than the adult pictured above as well.  While this juvenile wren is showing a smidgen of dishevelment, to my eye it is a vast improvement over the slovenly looking adult.  So individuals of the same species can be on different molt schedules.

Here are some pine warblers I photographed today that look like they are just coming off of a three-day bender.  These are young-of-the-year birds that are just acquiring their first basic (adult non-breeding) plumage.

Pine warbler

Pine warbler

Immature pine warbler molting from its dull juvenal plumage into its first adult plumage.

Immature pine warbler molting from its dull juvenal plumage into its first adult plumage.

Pine warbler

Pine warbler

Not all passerine species are looking so disreputable, though.  Here’s a red-eyed vireo photographed this morning, followed by a prairie warbler from a few days ago.

Red-eyed vireo

Red-eyed vireo

Prairie warbler

Prairie warbler

Admit it – those are some damned dapper little birds.  Why the difference?  Both of these species are neotropical migrants.  They leave the temperate latitudes in the fall to travel to the tropics (though a few prairie warblers will spend the winter in Florida).  Most migrants complete their post-nuptial molt before they begin their long-distance migration.  The extraordinary migratory flights of these birds demand a fresh plumage and all the aerodynamic advantages afforded by those new feathers.

Carolina wren

Carolina wren

Carolina wrens and pine warblers, on the other hand, are permanent residents.  They breed and overwinter in the state.  In many resident species, individuals maintain the same home ranges throughout the year.  This allows them the luxury of a more extended period of molt.  Molting is an expensive process – it requires a lot of energy and protein to produce a new set of feathers.   Molting and migrating simultaneously just isn’t practical for birds that must journey thousands of miles.

 

Missing Migrants

August 3, 2013

Sunrise at Lake George Conservation Area near Seville, FL

Sunrise at Lake George Conservation Area near Seville, FL.

After the impressive numbers of migrant warblers at Juniper Prairie a few days ago, I optimistically went looking for more this morning at Lake George Conservation Area, just west of Seville.  As is often the case when dealing with migrant passerines in Florida, though, it’s hard to predict from one day to the next what will turn up.

I left home a little after 6 to be at a small wet prairie on Combie Road in time for sunrise, at 6:46.  I barely made it, flying up Aces Rd in the post-dawn twilight to get there in time.  Sunrises can be unpredictable, too.  Not enough clouds on the horizon or particulates/vapor in the air to make ithis one really colorful or dramatic.  Once the sun rose above the treeline, it was bright yellow and overpowering.

A small wet prairie among the flatwoods.  The yellow flowers in the foreground are Polygala rugellii.

A small wet prairie among the flatwoods. The yellow flowers in the foreground are Polygala rugellii.

Bachman's sparrow carrying  prey back to the nest.

Bachman’s sparrow carrying prey back to the nest.

Still it was worth getting up to be there.  While I was jockeying around trying to find the best vantage point from which to shoot the sunrise, a blue grosbeak was singing from the mixed habitat to the west.  A few minutes later, I heard a Bachman’s sparrow singing at the wet prairie on Combie Rd.  I spotted and watched the sparrow sitting in a small pine for several minutes, singing a very soft subsong; he was carrying both a wolf spider and a cricket in his bill, and was still carrying them when he flew off.

Young eastern towhee still sporting juvenal plumage.

Young eastern towhee still sporting juvenal plumage.

Birds were immensely less impressive on this day compared to Ocala National Forest a couple of days earlier.  Nearly all were resident breeding species.  A few prairie warblers were the only migrants I saw. Mostly it was a morning to enjoy the habitat, the flora, and the non-avian fauna. Pluchea foetida, for example, was an attractive composite that I’d never noticed before.

Pluchea foetida

Pluchea foetida

The most interesting part of Lake George Conservation Area this morning,though, was Silver Pond Road, one of many roads in the area I hadn’t explored before.  I followed it for a couple of miles until it started to get dodgy.  About a mile in it became the boundary between the conservation area to the west, and pasture and mixed habitat on private property to the east.  Mostly I saw the same resident species I had been seeing all morning, but I did find some red-headed woodpeckers.  It’s always a welcome pleasure to find new sites for red-headed woodpeckers, which seem to be on the increase in Volusia County.

Zebra swallowtail nectaring at Diodia teres (I think).

Zebra swallowtail nectaring at Diodia teres.

The other interesting sighting on Silver Pond Rd was one or two zebra swallowtails, very fresh, nectaring persistently on Diodia growing in the road margins. These seem like very small flowers for a relatively large lep like a swallowtail, but he (they?) kept going back to them. I was driving like an idiot, zipping up the road a piece trying to anticipate the next nectaring spot, then scrambling to get the camera on target before they flew on.  I was only semi-successful.

I saw one hiker on that road, the only human I saw in the entire morning.  And that’s not a bad thing.

 

Juniper Prairie Warblers

July 31, 2013

Prairie warbler.

Prairie warbler.

There is hardly a month of the year when some birds aren’t migrating or engaged in some kind of nomadic or post-breeding movement in Florida.   Almost as soon as the last of the transient spring migrants have left the state (bobolinks and some of the shorebirds come to mind) sometime in mid-May, the first of the southerly moving birds begin to appear.   Still, summer birding in Florida tends to be relatively low in diversity, and mostly restricted to early or late in the day when the birds are most active and the temperature and humidity are at least somewhat tolerable.   Particularly for passerine birds, my favorites, Florida is dramatically and perplexingly low in breeding species.  So it’s always a great joy to me when “fall” passerine migration begins in earnest in late July and early August.  For some species, like yellow warblers, the peak of migration comes well before true fall, as delimited by the autumnal equinox, begins.    But I don’t see yellow warblers that much unless I happen to be in the right kind of habitat.   American redstarts, waterthrushes, and black-and-white warblers are also likely to appear as part of the vanguard of fall migration.  But it is the prairie warblers that really say to me that migration has begun.  They can be abundant at times, and very broad in their choice of habitat.  I saw my first prairie warbler of the season in my backyard on July 30, and that prompted me to hit the field on the 31st to look for these lovely little birds and their compatriots.

Juniper Prairie Wilderness in the Ocala National Forest has become one of my favorite places to look for passerines in the last couple of years.  This huge tract (roughly 14,000 acres) is bounded on the south by SR40, on the east by SR19, on the north by FR (Forest Road) 46, and on the west by FR33; within that huge expanse there are no fire roads or other access for motorized vehicles.   Hiking trails crisscross the wilderness and its mosaic of habitats, which include huge expanses of scrub in a variety of seral stages, “islands” of sandhill habitat dominated by longleaf pine, and a confusing array of aquatic, semi-aquatic, and seasonal wetlands that form in the depressions and basins characteristic of areas influenced by Karst topography.  This is the landscape written about by Marjorie Kinnan Rawlings in The Yearling; the area around Pat’s Island (one of the habitat islands of longleaf pine-dominated sandhills) was home to a small community of folks who farmed, hunted, and otherwise scratched a living from these often harsh habitats up until the 1930’s.

Extensive tract of oak scrub  in Juniper Prairie Wilderness.  New growth of Rusty Lyonia (Lyonia ferruginea) is very obvious right now.

Extensive tract of oak scrub in Juniper Prairie Wilderness. New growth of Rusty Lyonia (Lyonia ferruginea) is very obvious right now.

My birding in the wilderness is done almost entirely from the roads, though, since hiking trails through mostly soft sand are not particularly welcoming to my people.  In particular, FR46, which follows the northern boundary of the wilderness, is my favorite road for birding Juniper Prairie Wilderness.  In the approximately 5-mile stretch between SR19 and its intersection with FR33, it passes through a variety of types of scrub and some areas of open sandhills.  The older tracts of scrub, dominated by even-aged stands of sand pine, are typically lower in both bird and plant diversity than the more extensive areas of recently burned, harvested, or disturbed scrub, characterized by a rich variety of scrubby oaks and other sclerophyllous shrubby vegetation.

Juvenile Florida scrub jay surrounded by new growth of Rusty Lyonia (Lyonia ferruginea).

Juvenile Florida scrub jay surrounded by new growth of Rusty Lyonia (Lyonia ferruginea).

When you first enter the extensive tracts of Juniper Prairie scrub, a couple of miles west of FR46’s  intersection with SR19, the vastness of this low-stature prickly-looking habitat is stunning.  On first sight, it never struck me as a habitat that would harbor large numbers of birds.  This is the stage of scrub succession that is ideal for Florida scrub jay breeding, and to be sure the jays are here in big numbers.  It’s not uncommon to see and hear both scrub jays and blue jays very close to each other, though the blue jays tend to stick closer to the older tracts of scrub consisting mostly of sand pine.  Surprisingly, though, the density and diversity of mixed species flocks of smaller passerines in the oak scrub barrens can be astounding.  This is where I saw my only black-throated gray warbler several years ago, moving with a flock of more typical fall migrants.

Wednesday morning’s trip did not disappoint, though I found nothing as sensational as a black-throated gray warbler.  I came looking mainly for prairie warblers, and found them in numbers.   Nearly everywhere I stopped in the low oaky scrub habitat and looked, listened, or called for birds, I found them.  It wasn’t unusual to see 3-5 prairies traveling together as a group, often in the company of chickadees and titmice, the core members of many mixed-species flocks.  I didn’t keep count of precise numbers, but my guesstimate would be that I saw several dozen prairies.  Most were the more dully colored females or immatures; I don’t think I saw a single male showing full alternate (breeding) plumage, with the brilliant yellow underparts with prominent dark streaking and bold black semicircle under the eye.  Still, splendid little birds all.  And curious.

Inquisitive prairie warbler in scrub oak (with revolute leaf margins, CB!).

Inquisitive prairie warbler in scrub oak (with revolute leaf margins, CB!).

I regularly use playback of screech owl calls and mobbing vocalizations of a variety of passerines, along with the low-tech practice called “pishing”,  to entice birds into viewing range.   Several of the prairie warblers attracted using these techniques perched within 10-15’ of my car window, intensely curious and motivated to find the virtual predator that was provoking such a commotion.  In addition to the prairie warblers, a couple of other early season migrants/post-breeding wanderers were lured in – I saw a couple of yellow-throated warblers and one female-plumaged American redstart.   The resident breeding species were out in force as well – tufted titmice, Carolina chickadees, eastern towhees, white-eyed vireos, northern parulas, northern cardinals, Carolina wrens, blue-gray gnatcatchers, great crested flycatchers, and both blue and Florida scrub jays all made an appearance at one or many locations.   I saw, and heard, several family groups of scrub jays along this stretch of FR46 as well, with most containing several gray-headed juveniles.   Typical of the big-brained corvids, they seemed to be constantly on the move, exploring and soaking up important information about the habitat in which they will mature and eventually breed.

PRWA_07312013-40_Ocala NF Juniper

 

PRWA_07312013-31_Ocala NF JuniperOpen areas of the oak scrub, particularly those with some standing snags remaining from old mature sand pines, were filled with woodpeckers as well.  Red-headed woodpeckers are abundant in this area, as are northern flickers, downys and red-bellieds.  I even kicked up a couple of raptors, including a red-tailed hawk and an American kestrel.  I’m guessing the kestrel was of the paulus subspecies, the resident race that breeds in Florida.

A recently burned tract of scrub just beginning to regenerate.  This is where I saw the American kestrel, presumably a breeding bird.

A recently burned tract of scrub just beginning to regenerate. This is where I saw the American kestrel, presumably a breeding bird.

Prairie warbler in scrub oak.

Prairie warbler in scrub oak.

American redstart.

American redstart.

Yellow-throated warbler.

Yellow-throated warbler.

Vast expanses of oak scrub and flocks of lovely passerines –  what a great combination.  And between now and the peak of fall migration, which by my reckoning occurs in the latter half of October, it will just get better.

Welcome to Volusia Naturalist

Tiger Bay State Forest, Woody Tract.

                                                   Tiger Bay State Forest, Woody Tract.

Thank you for visiting my site and reading my drivel.  Blog posts will cover a range of natural history topics.  Many will be reports of my field excursions in and around Volusia County, while others will be more specific posts about particular subjects that interest me.

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