Evolution and Ecology

American Bittern: A Song in Still Frames

The ghostly winter silence had given way to the great spring murmur of awakening life.—Jack London, The Call of the Wild

Last weekend we took advantage of the spectacular weather and visited a number of our favorite birding haunts, including East Beach, Lafitte’s Cove (both Galveston Island, Texas), Pelican Island, and Brazos Bend State Park (BBSP). We visited the coastal sites with an eye toward seeing migrants, but alas there were no surprises, only the usual customers for this time of year both on the beach and in the motte.

At Brazos Bend State Park, Pilant Lake was again hopping with American Bitterns. They were busy hunting, singing, and displaying. On this visit, I caught one bird singing right out in the open in beautiful morning light around 7:45 am.

The song of the American Bittern, expressed onomatopoetically as oonk-a-loonk, is sometimes described as territorial and likely has a significant infrasonic component, below the threshold of human hearing. The singing is accompanied by a labored-looking performance in which the feathers of the head, neck, and shoulders (white shoulder plumes) are repeatedly roused and flattened. The beak is snapped shut producing a click that is apparently part of the song.

A bittern’s song is clearly aimed at other bitterns in the marsh as they answer each others’ calls. What exactly is being communicated is in question as these birds are on their way to breeding grounds far north of coastal Texas, and they are not likely carving out territories at BBSP. Perhaps they are merely exercising and practicing for the important performances to come on actual breeding grounds.

The series of six images below records one song, a wavelength, if you will, within a performance that may contain many repetitions of the same. All images were taken with a Canon EOS 7D + 600mm f/4L IS (+1.4x TC) under natural light, and are uncropped. Something approximating 0.5 seconds separates each frame.

American Bittern Calling: Image 1
Singing American Bittern 1, Pilant Lake, BBSP, Texas.
American Bittern Call: Image 2
Singing American Bittern 2, Pilant Lake, BBSP, Texas.
American Bittern Call: Image 3
Singing American Bittern 3, Pilant Lake, BBSP, Texas. Note the nictitating membrane.
American Bittern Call: Image 4
Singing American Bittern 4, Pilant Lake, BBSP, Texas.
American Bittern Call: Image 5
Singing American Bittern 5, Pilant Lake, BBSP, Texas.
American Bittern Call: Image 6
Singing American Bittern 6, Pilant Lake, BBSP, Texas.

©2015 Christopher R. Cunningham. All rights reserved. No text or images may be duplicated or distributed without permission.

More Snowy Egret Fishing Techniques

Snowy Egret shadowing two White Ibis, Frenchtown Road, Bolivar Peninsula, Texas
A Snowy Egret Shadows Two White Ibises, Frenchtown Road, Bolivar Peninsula, Texas. Canon EOS 7D/600mm f/4L IS (+1.4x TC). High-speed synchronized fill-flash.

Salt marshes, tidal channels, and lagoons along Frenchtown Road, Bolivar Peninsula, Texas often make for exceptional birding. On our last visit to Frenchtown Road (8-10 AM, 1/17/15), I observed several interesting avian fishing techniques at low tide among the exposed oyster patch reefs. Although a number of bird species (including Short-billed Dowitchers, Killdeer, Spotted Sandpipers, and American Avocets) were taking advantage of the low water level, a Snowy Egret was being especially opportunistic. I made observations referenced in this post on the north shore of the western extremity of the east-west channel. j

Among waders, Snowy Egrets may have the widest repertoire of hunting and fishing techniques, and I have written about several of them, including blowing bubbles to attract prey and shadowing Pied-billed Grebes from the shore as the latter spooked up prey, among others. At Frenchtown Road, this Snowy Egret shadowed a group of White Ibises as they hunted the shallows for infaunal invertebrates along the margins of the exposed oyster reefs at low tide. Presumably the ibises flushed prey, thus saving the egret the energy of exercising its most famous hunting technique, that of waving its bright yellow feet.

More interesting was when a Double-crested Cormorant went zooming back and forth, through the channels between reefs. As the cormorant swam past, the Snowy Egret launched into a frenetic dance and struck at prey in the cormorant’s wake, not unlike the dancing between bouts of underwing fishing exhibited by Reddish Egrets and Tri-colored Herons. This type of commensal behavior has been documented previously in the scientific literature (Bennett and Smithson, 2001; Emlen and Ambrose, 1970) and on-line for interaction of Snowy Egrets with such species as White Ibises, Double-crested Cormorants, Blue-winged Teal, and Red-breasted Mergansers.

These observations suggest several questions: Why do Snowy Egrets Exhibit such a wide range of hunting behaviors relative to other waders? How many new strategies remain to be be discovered? Given the widespread distribution of Snowy Egrets across the Americas, do Snowy Egrets interact with only a handful of other species, or rather do they simply look for prey-flushing disturbances, irrespective of the species/source? Clearly, there are many more observations and interpretations to be made.

Snowy Egret Wake Fishing, Frenchtown Road, Bolivar Peninsula, Texas
Wake-fishing Snowy Egret, Frenchtown Road, Bolivar Peninsula, Texas. The cormorant was patrolling the channels between exposed oyster reefs like a submarine when the Snowy Egret leapt into the wake in search of prey. Canon EOS 7D/600mm f/4L IS (+1.4x TC). High-speed synchronized fill-flash.

You can observe a lot by watching.—Yogi Berra

References:

Bennett, J., and Smithson, W. S. 2001. Feeding associations between Snowy Egrets and Red-breasted Mergansers. Waterbirds 24 (1): 125-128.

Emlen, S. T., and Ambrose III, H. W. 1970. Feeding interactions of snowy egrets and red-breasted mergansers. Auk 87: 164-5.

©2015 Christopher R. Cunningham. All rights reserved. No text or images may be duplicated or distributed without permission.

Winter’s Amphibian Hunters

In seed time learn, in harvest teach, in winter enjoy.—William Blake

Great Blue Heron with Siren intermedia, Pilant Lake, Brazos Bend State Park, Texas
Great Blue Heron with Lesser Siren (Siren intermedia), Pilant Lake, Brazos Bend State Park, Texas. Canon EOS 7D/600mm f/4L IS (+1.4x TC). High-speed synchronized fill-flash.

The south side of Pilant Lake, Brazos Bend State Park, Texas is the best place I know to photograph wader hunting and fishing behavior in a freshwater habitat. This winter, Pilant Lake has been a rich source of observations involving waders taking a variety of prey, amphibians in particular. Over the past few years I had heard several reports of Great Blue Herons taking Lesser Sirens (Siren intermedia), large salamander-like amphibians that have lost their hind limbs through the evolutionary process, from the area immediately north of the observation tower. This grassy area contains scattered ponds and puddles and a few taller, woody plants here and there. The substrate appears irregular, soft, and saturated with water.

Ever since learning that sirens were frequently taken here, I have kept an eye on the area, especially during winter (when most of the reported events occurred), and on other areas in the park that look the same. Judging by reports from other birders, on several occasions I had apparently just missed a heron taking a siren. On 1/24/15, my patience finally paid off, though. A Great Blue was hunting very near the tower, so I set up, chimped my settings, and waited for the action to unfold. Almost immediately the bird plunged it head nearly eye-deep into the muck and froze.

Great Blue Heron with Beak in Siren Burrow, Pilant Lake, Brazos Bend State Park, Texas
Great Blue Heron with Beak in Siren Burrow, Pilant Lake, Brazos Bend State Park, Texas. Canon EOS 7D/600mm f/4L IS (+1.4x TC). High-speed synchronized fill-flash.

I could tell that the bird was straining to pull up something big. At that point I knew that the heron had found a siren in a burrow—any lesser critter would have been yanked out immediately! After about five seconds, the bird pulled its head up without a meal. Over the next hour or so, the bird waited patiently over the burrow. Finally the bird struck into the mud again and dragged out the huge wriggling amphibian. The bird had speared the siren in the right shoulder region through to the throat with the lower beak and clamped the amphibian in place with the upper beak. Because a noisy group of babbling tourists had descended upon the tower, the heron almost immediately flew off with its catch. Pity.

Great Egret with Frog, Pilant Lake, Brazos Bend State Park, Texas
Great Egret with Southern Leopard Frog (Rana sphenocephala), Pilant Lake, Brazos Bend State Park, Texas. Canon EOS 7D/600mm f/4L IS (+1.4x TC). High-speed synchronized fill-flash.

In addition to sirens, this area is rich in other amphibians (especially frogs) during winter. Most commonly, waders take American Bullfrogs (Rana catesbeiana) and Green Treefrogs (Hyla cinerea), along with an occasional Southern Leopard Frog (R. sphenocephala). Green Treefrogs are most often taken from the water hyacinth that grows in profusion in Pilant Lake, as well as taller plants that grow at the margin of the water. In summer, I have seen Little Blue Herons and Great Blue Herons take Eastern Newts (Notophthalmus viridescens) in this area, too.

Little Blue Heron with Green Tree Frog, Pilant Lake, Brazos Bend State Park, Texas.
Little Blue Heron with Green Tree Frog (Hyla cinerea), Pilant Lake, Brazos Bend State Park, Texas. This bird picked treefrogs from tall vegetation at the water’s edge. Canon EOS 7D/600mm f/4L IS (+1.4x TC). Natural light.

Amphibians are the most exciting prey items that you are likely to see being grabbed by waders at Pilant Lake—mostly you will see invertebrates like crawfish and water tigers being eaten. Small fish are also frequent prey. Eventually I hope be on hand when a water snake or baby alligator is grabbed. I have heard reports of American Bitterns taking songbirds from the marsh vegetation, and photographs exist of Great Blue Herons grabbing baby nutria in similar environments. It’s only a matter of time before I can document these relatively rare and exciting events at Pilant Lake.

American Bittern with Green Tree Frog, Pilant Lake, Brazos Bend State Park, Texas
American Bittern in Water Hyacinth with Green Treefrog (Hyla cinerea), Pilant Lake, Brazos Bend State Park, Texas. Green Treefrogs range in color from bright green to yellow and brown. Canon EOS 7D/600mm f/4L IS (+1.4x TC). High-speed synchronized fill-flash.

©2015 Christopher R. Cunningham. All rights reserved. No text or images may be duplicated or distributed without permission.

The Yellow-eyed Rump-warmer

Sunny days (especially sunny weekend days) seem to be in short supply along the Texas Gulf Coast this winter. Happily, this weekend should be among those rare sunny occasions—so we’re headed to Brazos Bend State Park (BBSP) to see if we can spot the Least Grebes we saw just after the new year. Allow me take you back in time a few weeks . . . . New Year’s Day had come in with a grudge—weeks of damp and dreary days latched on like leeches and drained the life right out of us. So, when the first Sunday of 2015 rotated into place with a bright, sunny sky, we geared up and headed out, giddy with optimism.

Sunning Least Grebe at Brazos Bend State Park, Texas.
Sun worshipper. The Least Grebe fluffs its tail feathers to expose dark-pigmented skin on its rump and absorb solar energy for warmth on a cold January morning. Pilant Slough, Brazos Bend State Park, Texas. Canon EOS 7D/500mm f/4L IS (+1.4xTC). Natural light.

We weren’t the only ones venturing out to take advantage of the weather. This Least Grebe with it’s powder-puff posterior aimed sunward was practicing “high-sterned sunbathing,” according to the literature (Well, that’s a polite way of putting it!). The skin exposed by raising the feathers on its back-side is black and thought to absorb solar radiation. It seems reasonable enough. While in this position, I observed the bird paddle its feet back and forth to produce a stationary “waggle,” which could be interpreted as at the bird’s way of distributing the heat more evenly. You can see faint ripple-marks produced by our rump-warming friend in the photo above.

Water beads up and rolls off the back of a Least Grebe.
Waterproof. Water beads off a Least Grebe’s back after emerging from a dive. Many types of waterbirds have the ability to waterproof their feathers and insulate themselves from the wet and the cold. Pilant Slough, Brazos Bend State Park, Texas. Canon EOS 7D/500mm f/4L IS (+1.4xTC). Natural light.

The Least Grebe drew quite a crowd of onlookers along Pilant Slough at BBSP. Aside from being downright adorable, Least Grebes are infrequently seen in our neck of the woods. We usually see Pied-billed Grebes at BBSP. Although Pied-billed Grebes can be seen all over the US, Least Grebes are a tropical to sub-tropical species, and the Texas Gulf Coast populations are at the northern extremity of their typical permanent range. Even our mild Texas freezes can be fatal. As we left the park, I was excited to see two Least Grebes together. We’re hoping that they’re a mated pair and make it through our winter to raise a few broods!

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Do you see that out there? The strange unfamiliar light? It’s called the Sun. Let’s go and get us a little.” – Nora Roberts, The Hollow

©2015 Elisa D. Lewis. All rights reserved. No text or images may be duplicated or distributed without permission.

Stalking Forest Birds

Tufted Titmouse on Tree Trunk, Brazos Bend State Park, Texas
Tufted Titmouse Hunting on Lichen-encrusted Tree Trunk, Brazos Bend State Park, Texas. This bird ran up and down the trunk in search of caterpillars. Canon EOS 7D/500mm f/4L IS (+1.4x TC). Natural light.

About this time of year we always begin planning for our big summer birding trips. We try and include as many different types of habitat as possible. This year we will focus on the high elevation forests of the West. Finding and photographing forest birds is the toughest challenge I know in photography: it makes getting desert (and even marsh) birds seem simple by comparison. The openness and spectacular, clear light of the desert can make shooting a joy. The complex three-dimensional nature of the forest, often with shafts of brilliant illumination adjacent to patches of near-darkness, can test the capabilities of the birder-photographer.

Red-bellied Woodpecker, Edith L. Moore Nature Sanctuary, Houston, Texas
Bye-bye, Now! Red-bellied Woodpecker, Edith L. Moore Nature Sanctuary, Houston, Texas. Canon EOS 7D/500mm f/4L IS (+1.4x TC). High-speed synchronized fill-flash.

I have chased birds in many forests, and I am always a bit apprehensive about birding and shooting in these environments (and spending my precious, precious vacation time here) for one main reason: it’s possible to come away with nothing at all—no good shots or even a good look! Forest birds (songbirds especially) are often so suspicious and spooky that you may get one glimpse, and they’re gone! In the really big parks, they can disappear into the vastness in a snap. In the really tall trees (like those in Sequoia National Park!) the birds can just zoom up to fantastic heights and wait for you to go away.

Although not especially spooky, the tree-clinging birds like treecreepers, nuthatches, and woodpeckers are a special challenge to watch and photograph. It’s almost comical how woodpeckers will sometimes spiral around a tree trunk to get away from the hapless photographer! Brown Creepers may allow a very close approach, sometimes almost ignoring the shooter, as they hop up a trunk in search of arthropods only to sail downwards to the base of the next tree and begin the process again. Nevertheless, Brown Creepers are really hard to photograph as they cling to the tree trunks, staying in the shadows and deep recesses in the bark, and will even spiral around to the other side of the trunk to hide from the photographer in woodpecker fashion. In contrast to creeper behavior, nuthatches often hop down the trunk in search of prey—but they, too, cling to the trunk and poke into nooks and crannies making shooting difficult much of the time.

Athough I love the marshes, swamps, estuaries, tidal flats, and bottomland forests of the Texas Gulf Coast, I look forward to getting to very different habitats. The steep, high-altitude alpine habitats I have in mind for this summer will probably require quite a bit of sans-supertelephoto, binoculars-alone birding—unless I can talk Elisa into scouting out ahead and waiting for me at elevation with a defibrillator!

Brown Creeper, Brazos Bend State Park, Texas
Brown Creeper, Brazos Bend State Park, Texas. Note the stiff, pointed, woodpecker-like tail feathers used for propping the bird up against the trunk. Canon EOS 7D/500mm f/4L IS (+1.4x TC). Natural light.

A forest bird never wants a cage.—Henrik Ibsen

©2015 Christopher R. Cunningham. All rights reserved. No text or images may be duplicated or distributed without permission.

It’s a Wren Thing

Singing House Wren, Moose, Wyoming
Singing House Wren, Moose, Wyoming. Occurring from Canada to southern South America, House Wrens are one of the most widespread birds in the Americas. They are also one of the most aggressive small birds, vigorously defending their cavity nesting sites. Canon EOS 7D/500mm f/4L IS (+1.4x TC). Natural light.

Several weeks ago it seemed as if Marsh Wrens were everywhere we were along the Upper Texas Coast. One minute they were singing, and the next they were hiding. Then, just as mysteriously as they appeared, the Marsh Wrens disappeared completely. A week later, there were Carolina Wrens–also alternately singing and sneaking–where the Marsh Wrens had been before. House Wrens, too, should be around at this time of year, but where are they? Hiding, no doubt.

The name for the Wren Family, Troglodytidae, refers to a “creeper into holes, or cave dweller.” One can, of course, think of many examples to justify this name. The booming voices of Canyon Wrens can be heard up and down the arid canyons they inhabit. They are fun to watch as they climb up vertical cliff walls and poke around nooks, crannies, and caves. House Wrens nest in cavities, and we’ve seen Rock Wrens in the Gila National Forest (New Mexico) nesting in limestone caves.

While birding the rain forests of Olympic National Park, Washington, we were treated to the incredibly loud and penetrating songs of the Winter Wren. Finding and photographing the birds was a challenge, though. These birds favor the understory vegetation among the massive fallen logs of mighty conifers. This humid, gloomy, atmospheric environment is low on light, and the birds scurried and sneaked suspiciously among the shadows when not serenading.

Marsh Wren, Pilant Lake, Brazos Bend State Park, Texas
You’ve already seen enough: A quick look over the shoulder, and then back into the marsh. Marsh Wren, Pilant Lake, Brazos Bend State Park, Texas. Canon EOS 7D/600mm f/4L IS (+1.4xTC). Natural light.

Be they House, Carolina, Canyon, Rock, Cactus, Marsh, or Winter, all wrens seem to have this now you-see-me, now-you-don’t personality. One minute they are singing their lungs out obliviously ten feet from the birder, the next they re scurrying and hiding.

Singing Cactus Wren, Cave Creek Canyon, Arizona
Singing Cactus Wren, Cave Creek Canyon, Arizona. This bird hid in a pile of brush when not singing. Canon EOS 7D/600mm f/4L IS (+1.4x TC). Natural light.
Singing Carolina Wren, Pilant Lake, Brazos Bend State Park, Texas
Singing Carolina Wren, Pilant Lake, Brazos Bend State Park, Texas. Canon EOS 7D/600mm f/4L IS (+1.4x TC). Natural light.

Of course, this contradictory behavior is the result of two competing impulses. Most of the time wrens are secretive and shy—like most birds as they try to remain inconspicuous to predators. Then the singing begins, for all the reasons songbirds sing. They have no secrets . . . from potential mates and pretenders to their kingdoms, that is.

How infinitely charming, though, when after an hour or so of playing hide-and-seek with the birder, a wren hops up onto stump or low branch and starts his aria, “L’amour est un oiseau rebelle” (Love is a rebellious bird)! Fortississimo, if you please!

Winter Wren, Olympic National Park, Washington
Singing in the Darkness: Winter Wren, Olympic National Park, Washington. Canon EOS 7D/500mm f/4L IS (+1.4x TC). Natural light.

Contradictions do not exist. Whenever you think you are facing a contradiction, check your premises. You will find that one of them is wrong.—Ayn Rand

 ©2014 Christopher R. Cunningham. All rights reserved. No text or images may be duplicated or distributed without permission.

High Drama at Low Tide

Black-bellied Plover with ghost shrimp
Black-bellied Plover with Ghost Shrimp (Family Callianassidae), Frenchtown Road, Bolivar Peninsula, Texas. Canon EOS 7D/500mm f/4L IS (+1.4x TC). Natural light.

Hello again, friends! Chris’ last post reminded me of the photos I have to share of a Black-bellied Plover plucking ghost shrimp from their burrows. Watching shorebirds pull infaunal invertebrates from tidal mudflats is definitely my idea of a good time! These photos were taken last April, when the bird was starting to molt into its breeding plumage.

I knew this plover had something big when the typical run-pause-pluck, run-pause-pluck hunting style was suspended at the “pluck.” There it was, its bill up to the nostrils in mud, completely frozen. A few beats later, a mound of mud erupted as the plover slowly pulled up a bizarre looking worm (because everything’s a worm-right?). Well, turns out, it was an arthropod – a ghost shrimp to be precise – and this little bird was a master shrimper. Fastidious too. After each catch, the black-belly would run to the water’s edge to rinse the ghost shrimp off before swallowing it whole.

Three image series of a Black-bellied Plover pulling a ghost crab out of its burrow in a mudflat.
Watch Me Pull a Ghost Shrimp Out of This Mudflat! A Black-bellied Plover “magician” extracts a ghost shrimp from its burrow at Frenchtown Road, Bolivar Peninsula, Texas. Canon EOS 7D/500mm f/4L IS (+1.4x TC). Natural light.

As a photographer, these are the moments I shoot for. As a wildlife watcher, these little dramas starring avian predators and their cryptic prey open small windows into life beneath the surface. Considering the diversity of species and numbers of birds that make their livings pulling food from the earth, I get a sense of how alive the ground beneath our feet really is.

I knew, of course, that trees and plants had roots, stems, bark, branches and foliage that reached up toward the light. But I was coming to realize that the real magician was light itself.–Edward Steichen

©2014 Elisa D. Lewis. All rights reserved. No text or images may be duplicated or distributed without permission.

Hunting High and Low

Little Blue Heron with Green Tree Frog, Pilant Lake, Brazos Bend State Park, Texas
Little Blue Heron with Green Tree Frog (Hyla cinerea), Pilant Lake, Brazos Bend State Park, Texas. Canon EOS 7D/600mm f/4L IS (+1.4x TC). Natural light.

Hunting High. Recently I was stalking a Little Blue Heron as it worked its way through the vegetation at water’s edge, Pilant Lake, Brazos Bend State Park. The vast majority of the time, waders are looking down in their search for fish, amphibians and invertebrates. This time the bird was looking up, inspecting the plants as it went. I new what this meant, having seen it three or four times before at Elm Lake: The bird was after tree frogs! (Sidebar: sometimes waders act like this when they’re looking for dragonflies or spiders.) Interestingly, the water level in this part of the park seems to be down a bit from last year, and perhaps the tree frog hunt may be in response to this. Because I knew what was coming, I was able to get a nice series of shots documenting the bird eating four tree frogs.

Piping Plover with worm, Bryan Beach, Texas
Piping Plover with “Worm,” Bryan Beach, Texas. Canon EOS 7D/600mm f/4L IS (+1.4x TC). High-speed synchronized fill-flash.

Hunting at the surface. Cold weather fun can be had watching shorebirds pull infaunal invertebrates from tidal mudflats. Once in a while it’s a ghost shrimp or a crab, but often these meals are unidentifiable to me, and I just peg them as “worms.” I remember one of my professors on a rant about the term “worm” only being used out of a state of complete ignorance as many phyla of marine organisms could be lumped under that term. In this case, guilty as charged! Most of the time I have no idea what these little shorebirds are prying wriggling from the muck! It’s always exciting to watch, and every so often a bird grabs something big, nasty, and identifiable!

Hunting low. Perhaps the most suspenseful type of hunt to watch is one in which prey is sought from below the surface of the water. Sure, most of the time if you are in a freshwater environment, a small fish, tadpole, or larval invertebrate is plucked up, but sometimes really big prey items are dragged out thrashing and snapping. But turnabout is fair play. It’s not uncommon to see waders poking around in the shallows only to go running away squawking after having poked or prodded something really big, toothy and nasty like an alligator gar or . . . God knows what! And considering the beasties that swim beneath the waves of the salty seas, I marvel at the boldness of waders as they hunt in the marine shallows.

Willet with Crab, Frenchtown Road, Bolivar Peninsula, Texas
Willet with Mud Crab, Frenchtown Road, Bolivar Peninsula, Texas. This crab is likely the oystershell mud crab (Panopeus simpsoni), but I invite comments from anyone who knows betterThese small crabs have an enlarged tooth on the moveable finger of the major chela (noted in some other images) and are common among the oyster reefs of the Gulf Coast, along with some other mud crab species. Canon EOS 7D/600mm f/4L IS (+1.4x TC). High-speed synchronized fill-flash.

Finally, one of my goals for this winter is to capture images of a Great Blue Heron grappling with a Siren intermedia. During winter, the place to look for these giant amphibians being dragged from their burrows is the edge of Pilant Lake just north of the observation tower. However, this year the terrain in this area looks very different from the recent past: It is drier and much overgrown. Fortunately, Pilant Slough just to the south and east looks very much like Pilant Lake has in recently past years. This occurred to me as I noted a Great Blue standing right in the middle of the slough. Clearly, this is the spot to watch for the siren hunt this year!

Perhaps, after all, America never has been discovered. I myself would say that it had merely been detected.—Oscar Wilde

©2014 Christopher R. Cunningham. All rights reserved. No text or images may be duplicated or distributed without permission.

Birding for Tyrant Flycatchers of the Genus Tyrannus

Scissor-tailed Flycatcher at Pelican Island, Texas
The Most Spectacular Member of the Tyrannus Clan: Scissor-tailed Flycatcher (T. forticatus) on Pelican Island, Texas. Exceptional in coloration and plumage, the Scissor-tailed Flycatcher is a stand-out among the relatively conservative-looking members of its genus. Scissor-tails prefer open, grassy environments with small clumps of trees from which to hunt. They also love to perch and hunt along barbed-wire fence lines and are a common sight in summer on the plains of the southern U.S. Canon EOS 7D/600mm f/4L IS (+1.4x TC). High-speed synchronized fill-flash.

The family Tyrannidae (Tyrant Flycatchers) is primarily a South American group. Of over 370 species, only 35 have ranges that extend far enough north to reach the United States. Eight genera of tyrant flycatchers occur in North America, north of Mexico. Considered by evolutionary biologists to be among the most primitive of songbirds, tyrannids are nevertheless highly successful, ranging from Patagonia, and even the Falkland and Galápagos Islands, to Canada. These birds occur across a wide variety of habitats, from bottomland forests to the high Andes.

Due to their bold personalities and active hunting behaviors, the Tyrant Flycatchers of the genus Tyrannus (kingbirds and kin) are some of the most exciting birds to watch. Exhibiting a rather limited palette of colors relative to some other songbirds, ranging primarily from browns and olives to gray on top (plus orange or red semi-concealed crown stripes for display), and a variety of shades of yellow below, species of Tyrannus may never be as popular as warblers with birders. But what they lack (usually) in terms of showy colors they make up for in personality and behavior.

Couch's Kingbird at Estero Llano Grande State Park, Texas
Couch’s Kingbird (Tyrannus couchii) on Cable at Estero Llano Grande State Park, Rio Grande Valley, Texas. This young bird showed no fear of me whatsoever, despite a close approach. Canon EOS 7D/600mm f/4L IS (+1/4x TC). High-speed synchronized fill-flash.

Other than the Great Kiskadee, perhaps, Kingbirds are the most conspicuous of the North American flycatchers. These large, aggressive birds will not tolerate being pushed around by other, larger birds like crows or even raptors. Although they will eat fruit and seeds during certain times of the year (depending on the Kingbird species), insects form an integral part of their diets.

From a perch, they will hawk large insects from the air above water or ground and also grab prey from the ground. The fact that they return again and again to a perch can make photography relatively easy and enjoyable. After locating an avian photographic subject, I often snap few frames, advance a few paces, snap a few frames, advance a few paces, and so on. Some bird species will flush as soon as they see a human. Others will hesitate until a particular distance is breeched (minimum approach distance). Tyrant flycatchers, too, eventually flee hesitantly into the air upon a close enough approach, but I can’t help feeling as though these bird are asking themselves: Do I really have to leave? Can I take this guy?

Cassin's Kingbird at Cave Creek Ranch, Arizona.
Cassin’s Kingbird (Tyrannus vociferans) on Mesquite at Cave Creek Ranch, Arizona. This bird flashed a bright orange (on top) and red (below) crown-stripe upon takeoff and could easily be confused for a Western Kingbird. Considering a number of other images together, however, the identification was based upon absence of bold white outer tail feather margins, lighter brownish wings with pale feather edges, and a crescent-shaped white patch or “mustache” below eye. In such similar species, though, there is room for uncertainty. Canon EOS 7D/600mm f/4L IS (+1.4x TC). High-speed synchronized fill-flash.

Although not as difficult to tell apart as some Empidonax Flycatchers, which are literally indistinguishable based on appearance alone, some species of Tyrannus are quite tricky to identify. Even based on a reasonably good photograph, experienced birders may disagree about the identity of a specific individual. Cassin’s and Western Kingbirds, for example, overlap in range in the West and are often confused. Likewise Couch’s, Tropical, and Western Kingbirds have overlapping ranges in the Lower Rio Grade Valley.

All these species, though, do have distinctive field marks and can in principle be distinguished. However, depending on the light and angle of view, colors can change. Vegetation can obscure minor or subtle features. In these troublesome cases, after exhausting reasonable avenues of identification, I try to live with the uncertainty–rather than decide which member of this sometimes look-a-like group I’ve spotted.

Eastern Kingbird on Hackberry at Anahuac National Wildlife Refuge, Texas
Eastern Kingbird (Tyrannus tyrannus) on Hackberry at the Skillern Tract, Anahuac National Wildlife Refuge, Texas. Kingbirds, like many other insectivorous birds, often hang around Hackberry trees. Canon EOS 7D/100-400mm f/4.5-5.6L IS. Hand-held, natural light.

The quest for certainty blocks the search for meaning. Uncertainty is the very condition to impel man to unfold his powers.—Erich Fromm

 ©2014 Christopher R. Cunningham. All rights reserved. No text or images may be duplicated or distributed without permission.

The Adaptable Cattle Egret

Cattle Egret with Feral Hog at Pilant Slough, Brazos Bend State Park, Texas
In Deepest, Darkest Texas: Cattle Egret with feral hog at Pilant Slough, Brazos Bend State Park, Texas. True pigs have been in the New World for centuries due to human introduction. Cattle Egrets commonly follow cattle around Texas pastures, but this is the first time I have seen the birds shadowing prey-flushing pigs. All photos Canon EOS 7D/600mm f/4L IS (+1.4x TC).

Cattle Egrets are among my favorite waders. They are slightly sinister in appearance and behavior as they sneak and skulk around the margins of grasslands and marshes in search of invertebrate and small vertebrate prey. And judging by their large minimum approach distance they are among the most suspicious and distrustful of birds.

Given their dislike of people, it’s ironic that the rapid expansion of Cattle Egrets across the New World in the latter half of the 20th Century has been aided by human agriculture. Not long before the 20th Century the Cattle Egret was an Old World species. The first Cattle Egret was seen in the New World in 1877; in North America in 1941, and it began breeding in Florida in 1953. Today, Cattle Egrets are widely distributed across the Americas.

A Cattle Egret in Breeding Colors at Smith Oaks Rookery, High Island, Texas
Spectacular: A Cattle Egret in Breeding Colors at Smith Oaks Rookery, High Island, Texas. Natural light.

Although we think that the Cattle Egret reached the New World on its own, the widespread distribution of livestock here, particularly cattle, has has greatly facilitated the bird’s spread. Today, Cattle Egrets snapping up grasshoppers and other prey flushed by cattle (or farm implements!) is a common American sight.

So in the Americas, the Cattle Egret is not a human-introduced species. Yet, I find it hard to consider it precisely a native species (over much of its range) given its close association with domesticated livestock. The Cattle Egret exists exactly at the intersection of man and the rest of nature. It is one of those species well adapted to live in a human-influenced, agricultural landscape. And, as the human population increases with its ever-increasing appetite for meat and animal products, the Cattle Egret’s future looks bright indeed.

Mating Cattle Egrets at the Smith Oaks Rookery, High Island, Texas
Mating Cattle Egrets at the Smith Oaks Rookery, High Island, Texas. Cattle Egrets now breed in rookeries with native species such as Great Egrets, Roseate Spoonbills, Tricolored Herons, and Snowy Egrets. Natural light.

It is not the strongest or the most intelligent who will survive but those who can best manage change.—Charles Darwin 

©2014 Christopher R. Cunningham. All rights reserved. No text or images may be duplicated or distributed without permission.

It’s Black Skimmer Nesting Season!

A Black Skimmer Turns an Egg, at Freeport, Texas
A Black Skimmer Turns an Egg, at Freeport, Texas. All images Canon EOS 7D/600mm f/4L IS (+1.4x TC) unless otherwise noted. Natural light.

Elisa and I recently took the opportunity to visit the Black Skimmer nesting colony at the Dow Chemical plant in Freeport, Texas during the company’s annual open house. In addition to the Black Skimmers, Gull-billed and Least Terns were present within the colony. Defense and reproduction were foremost on the birds’ minds.

Avian nesting colonies are defense mechanisms against numerous threats to eggs and chicks: Hundreds of pairs of eyes are better than one. Also, Black Skimmers are not aggressive defenders of nests as are some other colonial nesters (Common, Gull-billed and Least Terns, for example), and will nest among these species for protection. On the day we visited, Laughing Gulls loitered like juvenile delinquents on the margins of the colony hoping for a moment of inattention or distraction to grab eggs or chicks. Rats and other mammals like raccoons, can also be expected to prey on eggs and nestlings.

Gull-billed Tern over nest at Freeport, Texas
Vigilance: Gull-billed Tern Over Nest at Freeport, Texas.

Another Black Skimmer defensive tactic we observed was the “broken wing act” to distract attention from nests. In the cases I observed, I did not perceive a particular threat. Perhaps the birds were simply responding to a general level of stress due to a large number of human observers.

Black Skimmer Performing Broken Wing Act at Freeport, Texas
A Black Skimmer Performs the Broken Wing Act at Freeport, Texas. Canon EOS 7D/500mm f/4L IS (+1.4x TC). Natural light.

In addition to defensive behaviors, we observed several instances of Black Skimmers turning eggs. In marked contrast to snake and lizard eggs, almost all bird eggs must be turned often during incubation for proper development.

One of the most charming things I observed was pair feeding as part of the skimmer courtship ritual. In this ritual, the larger male Black Skimmer presents the female with a small fish. If she accepts the fish, the pair copulates. The female skimmer then eats the fish. Interestingly, terns exhibit a similar ritual—but female terns eats the fish before copulation.

On the photographic side, a persistent Tropical weather pattern continued in which moisture flowed up onto the coast from the Gulf providing high humidity and a dazzling, cloudy white sky. The unfortunate placement of the observation areas coupled with the atmosphere meant conditions for photography were poor. Because the birds were backlit, I had to wait for instances when they would turn their heads such that raking light could reveal feather detail and provide catchlights. Sometimes shooting during the Texas summer requires a little creativity.

Laughing Gull with a fish at Freeport, Texas
No Laughing Matter: Laughing Gulls with a fish at Freeport, Texas. Small groups of Laughing Gulls flanked the colony waiting for opportunities to prey on eggs and young. These two gulls couldn’t decide whether to eat or abandon (or bring back to their own young?) their nearly dried-up fish carcass. They kept dropping it and hestitantly picking it up again. Were they hoping for something better? A plump, juicy tern or skimmer chick, perhaps?

I always root for the defense.—Wellington Mara

 ©2014 Christopher R. Cunningham and Elisa D. Lewis. All rights reserved. No text or images may be duplicated or distributed without permission.

Transitioning Back into Summer Mode: Hunting Waders with a Camera

Great Egret Nestlings at Smith Oaks Rookery, High Island, Texas
Pure Id: Great Egret Nestlings at Smith Oaks Rookery, High Island, Texas. These guys are all about lunch. Natural light. All photos Canon EOS 7D/600mm f/4L IS (+1.4x TC).

Now that spring migration, the most exciting time of the birding year, is almost over, I have to seek adventure where I can find it. This often involves chasing waders around at Brazos Bend State Park (BBSP) as they hunt. Of course, a few of the spring (and summer) spectacles are still playing out–like the frenzy of nesting, breeding, and nurturing young observable at the coastal rookeries. Photographing this profusion of life-energy will be mosquito-bloodied interludes in my late spring and summer studies of wader feeding behaviors at BBSP.

Little Blue Heron with little crawfish at Pilant Lake, Brazos Bend State Park, Texas
Little Blue Heron with Little Crawfish at Pilant Lake, BBSP, Texas. High-speed synchronized fill-flash.

Although I’ve only been out to BBSP a few times recently, one thing already seems evident: 2014 is shaping up as the Year of the Crawfish. Despite hearing lots of frog song and even seeing lots of frogs jump when alligators move around, I haven’t been seeing waders eating frogs. But crawfish are being gobbled down left and right! Why are frogs not on the menu? Have I just missed them being eaten? Will wader tastes change with the summer?

White Ibis in breeding color with crawfish at Pilant Lake, Brazos Bend State Park, Texas
White Ibis in Breeding Color with Big Juicy Crawfish at Pilant Lake, BBSP, Texas. Natural light.

This is one of the eternal joys of birding: new observations that lead to questions and more questions. Sorting out (or at least attempting to) why some types of prey proliferate some years while others are scarce is an ongoing research problem. Some years there are spiders (terrestrial or aquatic) everywhere and are eaten by hungry birds, and some years there are frogs and tadpoles everywhere and are grabbed, but sometimes rejected. But if you travel this path beware: you may find yourself reading articles about fungal infections of spiderlings or how winter water temperatures affect crawfish populations or . . . you get the idea.

Yellow-crowned Night-Heron with little crawfish at Pilant lake, Brazos Bend State Park, Texas
Yellow-crowned Night-Heron with Little Crawfish at Pilant Lake, BBSP, Texas. Natural light.

Familiar things happen, and mankind does not bother about them. It requires a very unusual mind to undertake the analysis of the obvious.—Alfred North Whitehead

 ©2014 Christopher R. Cunningham. All rights reserved. No text or images may be duplicated or distributed without permission.