Evolution and Ecology

Look-a-like Little Sandpipers: Charmers of the Winter Mudflats

Posted February 22, 2014 by Chris Cunningham

Western Sandpiper at East Beach, Galveston Island, Texas — *Hunting Western Sandpiper* *(Calidris mauri)* *on a Beautifully Rippled Surface* at East Beach, Galveston Island, Texas. Canon EOS 7D/600mm f/4L IS (+1.4x TC). High-speed synchronized fill-flash.

East Beach, Galveston Island, Texas at low tide is a magical place: a place equally suited for a biology or geology field trip. Gorgeous bedforms of a dozen kinds—those structures formed by the action of water on sediments like ripple marks and dunes—bring back memories of sedimentology classes many moons ago. Running around on theses surfaces (or occasionally trying to pry a recalcitrant worm from the sand and mud) are the sandpipers.

Dunlin at East Beach, Galveston Island, Texas — *Dunlin* *(Calidris alpina)* at East Beach, Galveston Island Texas. Canon EOS 7D/500mm f/4L IS (+1.4x TC). Natural light.

In their winter colors, the smallest ones, Sanderlings, Dunlins, Least Sandpipers, and Western Sandpipers sometimes test the birder’s ability to distinguish one species from another. In this endeavor, behavior is often just as good a guide to identification as are the details of appearance.

Sanderlings are perhaps the most charming and easiest to identify of the sandpiper clan as they chase the waves as they drain back out to sea, plucking stranded invertebrates and detritus as they go. Dunlins typically poke about at the strand line, and Western Sandpipers often explore the puddles of the intertidal zone. Least Sandpipers tend to probe for food along the margins of vegetation.

Sanderling at East Beach, Galveston Island, Texas — *Sanderling* *(Calidris alba)* *in Frosty Winter Colors* at East Beach, Galveston Island, Texas. Canon EOS 7D/500mm f/4L IS (+1.4x TC). Natural light.

Although I tend to notice sandpipers most often in intertidal habitats, all of these birds can also be found in freshwater and terrestrial environments such as the margins of lakes, flooded fields, and freshwater marshes. All birds mentioned in this post are still common, but Dunlin and Sanderlings are declining in numbers, mainly due to human use (and misuse) of beaches and other coastal habitats . . . yet another tragic tale of our time.

Least Sandpiper at Brazos Bend State Park, Texas. — *Least Sandpiper (Calidris minutilla)* in a freshwater marsh, Pilant Lake, Brazos Bend State Park, Texas. Canon EOS 7D/600mm f/4L IS (+1.4x TC). Thanks to TE for pointing out these little fellows. High-speed synchronized flash.

Someday, after mastering the winds, the waves, the tides and gravity, we shall harness for God the energies of love, and then, for a second time in the history of the world, man will have discovered fire.—Pierre Teilhard de Chardin

Of Limpkins and Applesnails

Posted January 18, 2014 by Two Shutterbirds

Limpkin at the Celery Fields, near Sarasota, Florida — *Limpkin on a Snail Hunt* at the Celery Fields, near Sarasota, Florida. We had hoped to get a shot of a Limpkin eating a snail, but the four birds we saw would find snails and then high-tail it back into to the vegetation to eat them, only to reappear a few minutes later to continue the hunt. Canon EOS 7D/600mm f/4L IS (+1.4x TC). Natural light.

On a recent birding to trip to Florida we were excited to see Limpkins, odd rail-like birds that feed primarily (75%) on applesnails. Limpkins are snail specialists with slightly right-curving beak-tips to reach inside snail shells. Historically, Limpkins have fed on the Florida Applesnail, the one indigenous U.S. applesnail species. However, the U.S., especially the Gulf Coast, is currently under invasion by several additional species of Neotropical applesnails (Genus Pomacea, but we’ll leave the contested details of which species are which to the gastropod taxonomists!).

Two species of snail-eating birds appear to be taking advantage of this invasion: Limpkins and Snail Kites. Limpkins are reportedly expanding their range in Florida to harvest the explosion of invasive snails, and the Florida subspecies of Snail Kite appears to be rebounding from the brink of extinction based on the proliferation of prey. White Ibis also dine on applesnails and may be benefitting from increased food supplies.

Although these invasive mollusks seem to be benefiting these birds, many naturalists fear the applesnail invasion. These snails have become major agricultural pests in other parts of the world where introduced, and some species host the rat lungworm parasite (now doesn’t that sound pleasant?). Even in death applesnails pose a threat: shells discarded by Limpkins and Snail Kites serve as water reservoirs for the breeding of invasive Asian tiger mosquitos.

Seems that everywhere we go on our birding adventures we find invasives (or their impacts), or in researching these posts, read about the impacts invasives have on birds or the environment in general. Pristine environments are now non-existent. Even in parks and preserves billed as being “native,” cursory inspection of land or water soon usually reveals invasives, be they Chinese tallow trees, water hyacinth, Hydrilla, or privet—or applesnails. I somehow doubt, though, that Limpkins and Florida Snail Kites will accompany the applesnail invasion of Texas. Pity.

Apple Snail Egg Mass at El Franco Lee Park, Houston. — Applesnail (*Pomacea* sp.) egg mass at El Franco Lee Park, south Houston. Egg masses can be found on emergent vegetation in shallow water. Canon EOS 7D/500mm f/4L IS (+1.4x TC). Natural light.

Time sometimes flies like a bird, sometimes crawls like a snail; but a man is happiest when he does not even notice whether it passes swiftly or slowly.—Ivan Turgenev

Birding Myakka River State Park: Brazos Bend State Park’s Florida Cousin

Posted January 4, 2014 by Chris Cunningham

Tricolored Heron with Warmouth at Myakka River State Park, Florida — *Too big? Tricolored Heron with Warmouth* at Alligator Point, Myakka River State Park, Florida. Alligator Point is on an oxbow lake. After trying to swallow the fish a few times, this bird eventually gave up and walked away. Canon EOS 7D/600mm f/4L IS (+1.4x TC). Natural light on a dark, gloomy day.

Over the past week we were able to spend a few days at Myakka River State Park (MRSP) in western Florida near Sarasota. We were struck immediately by similarities to Brazos Bend State Park, Texas (BBSP). Both are subtropical low-relief state parks centered around rivers and lakes. The winter water bird avifaunas are also similar–with a few exceptions, Wood Storks and Double-crested Cormorants having the most conspicuously different abundances at the two parks.

Over the years I have only seen one Wood Stork at BBSP. On the other hand, Wood Storks proved to be common at MRSP during our stay, and we were able to observe them in flight overhead, underwing hunting/fishing and “wing flashing” (herding aquatic prey by waving a wing) at Alligator Point. The oxbow lake at Alligator Point provides the birder or photographer an excellent vantage point to observe bird behavior deep off the beaten track—but watch out for poison ivy! Pied-billed Grebes are present in small numbers (relative to BBSP) at MRSP, but Double-crested Cormorants are abundant and making a living the way the grebes do at BBSP, namely diving after prey in shallow freshwater lakes.

Double-crested Cormorant at Alligator Point, Myakka State Park, Florida — *Double-crested Cormorant* at Alligator Point, Myakka State Park, Florida. Canon EOS 7D/600mm f/4L IS (+1.4x TC). Natural light.

The prey are conspicuously different at these two parks, however. At this time of year at BBSP the birds seem to be consuming a mix of fish, amphibians (frogs and salamanders), and arthropods. At MRSP we only saw fish being taken–several species of gar, Tilapia, bass, and small catfish . . . although one Great Blue Heron was convinced he had a snake or Amphiuma salamander and pecked a poor stick to bits! The absence of crawfish prey struck me as remarkable, and I asked a ranger about it. He said that during the dry season, the crawfish remain in their burrows. Perhaps when the rains return and some the low-lying areas flood again, crawfish will be on the water bird menu.

In general, our time in western Florida has brought up a number of fascinating topics for thought, research, and future travel plans that will no doubt be discussed in this blog at some point in time. How are Tilapia (an invasive), for example, impacting the environment generally and wader diets in particular. Also, where are the amphibians? Could we be seeing another example of the global amphibian crisis? These questions make me want to bird this amazing park during other times of the year.

Wood Stork canopy fishing at Myakka State Park, Florida — *Double Wing Fishing(?) Wood Stork* at Alligator Point, Myakka River State Park, Florida. By creating a shadow, the under-wing-fisher can better see through the glare and spot prey beneath the surface. Reddish Egrets are best known for this technique, but this Wood Stork appeared to be using the same approach. The Wood Stork is considered an Endangered Species by the U.S. Fish and Wildlife Service. Canon EOS 7D/600mm f/4L IS (+1.4x TC). Natural light.

My parents didn’t want to move to Florida, but they turned sixty and that’s the law.–Jerry Seinfeld

Chinese Tallow Seeds: A Winter Food Resource for Birds

Posted December 28, 2013 by Two Shutterbirds

Myrtle Warbler eating Tallow wax — A Yellow-rumped Warbler (Myrtle Race) scrapes white wax (vegetable tallow) from a Chinese tallow tree seed at Anahuac National Wildlife Refuge (Skillern Tract), Texas. Note that many seeds show signs of being scraped. Canon EOS 7D/500mm f/4L IS (+1.4x TC). Natural light.

The Chinese tallow tree (Triadica sebifera) is a foreign invasive native to China and Japan. However, it’s not uncommon to see birds like House Finches and White-winged Doves eating Chinese tallow seeds, or to see Yellow-rumped and Orange-crowned warblers hunting insects and spiders among tallow leaves.

Chinese tallow fruits are three-lobed and contain three oily, wax-covered seeds. Recently Elisa caught Myrtle Warblers scraping wax from tallow seeds. Some birds even appeared to be squabbling over access to the choicest seeds.

Tallow seeds themselves are biochemically distinct from the wax coating, so birds consuming just tallow versus whole seeds will ingest different suites of compounds and receive different nutritional benefits. Chinese tallow seeds are more oil-rich than many seeds cultivated for human consumption such as soybeans, peanuts, and sunflower seeds, and show promise as the basis for a biodiesel industry in the U.S.

Many native plants lovers and land managers, however, consider the Chinese tallow a pestilence because of its hardy and invasive nature. Alarmingly, Chinese tallow trees now constitute 23% of all trees in the Houston area! Unfortunately Chinese tallows are highly invasive and here to stay. But on the up side, at a time of the year when arthropod abundance is at a low point, the Chinese tallow provides a vast nutritional resource for any birds capable of consuming its seeds.

White-winged Dove with Chinese Tallow seed in Houston — White-winged Dove with Chinese tallow Seed in Houston. Canon EOS 7D/500mm f/4L IS (+1.4x TC). Natural light.

Irony regards every simple truth as a challenge.—Mason Cooley

Mottled Ducks: Threatened by Man and Nature

Posted December 14, 2013 by Chris Cunningham

Female Mottled Duck at Rockport, Texas — *Portrait: Female Mottled Duck* at Rockport, Texas. Male and female Mottled Ducks are quite similar looking. Females have an orangish bill (often with varying degrees of black mottling, especially near the base), whereas males tend to have more yellowish bills without black mottles. This female’s bill is relatively free of black mottles. Canon EOS 7D/600mm f/4L IS (+1.4x TC). High-speed synchronized flash.

Male Mottled Duck at Rockport, Texas. — *Portrait: Male Mottled Duck.* Male Mottled Ducks are sometimes described as having “cleaner” faces than the females. Canon EOS 7D/600mm f/4L IS (+1.4x TC). High-speed synchronized flash.

Over the Thanksgiving holiday we took a short road trip to Corpus Christi and environs, specifically with the hopes of seeing ducks, waders, and shorebirds. At Rockport, Texas I observed a small group of Mottled Ducks hanging around in the shadows under a dock. We see Mottled Ducks from time to time, but seeing these birds up close got me to reading more about them: they are unusual for a number of reasons. These dabblers are rather drab and show little sexual dimorphism relative to some other ducks. They are also non-migratory and reproduce in Southern marshes, rather than at higher latitudes like most other North American ducks.

Their status is of “least concern,” although their estimated numbers are only in the tens of thousands in Texas, a major part of their range. Mottled Ducks do have an unusually limited geographic range, essentially around the Gulf of Mexico, across Florida, and with an introduced population in South Carolina. There are actually two subspecies of Mottled Ducks: Anas fulvigula maculosa (Alabama to Veracruz, Mexico) and A. f. fulvigula (Florida). Numerous references suggest that Mottled Ducks, like many species, are under threat from habitat destruction such as the draining of marshes. Conventional wisdom has it that habitat destruction is more of a threat than human hunting—although seeing internet images of piles of shotgun-blast killed Mottled Ducks leads me to question that. Apparently some duck hunters collect bands, and Mottled Ducks are a heavily banded species (about 5%) thus making them a popular target.

Mottled Ducks are part of the “Mallard complex,” a group of approximately 20 closely-related species and subspecies of ducks. As a result, Mottled Ducks face another unusual challenge: gene flow from feral introduced Mallards. These “pen-raised” released and escapee Mallards generally do not migrate to northern breeding grounds. Naturally sexually aggressive male feral Mallards are interbreeding with local Mottled Ducks, thus undermining the genetic isolation of the latter and producing infertile hybrids. This problem is most significant in Florida, leading some to fear for the extinction of the Florida subspecies, although there are reports of hybrids from other areas, including Texas.

Only time will tell if the relentless crush of human ecological trouble-making will spare these lovely creatures.

Mated pair Mottled Ducks at Lafitte's Cove, Galveston Island, Texas. — Are their best days behind them? *Mated Pair of Mottled Ducks* at Lafitte’s Cove, Galveston Island, Texas. Male and female Mottled Ducks are easy to tell apart at a distance. In addition to different bill color, females tend to have a darker, more distinct eye-line and sometimes a more distinct black “fleck” just behind and below the eye, which at a distance can almost resemble a tear-drop. Canon EOS 7D/600mm f/4L IS (+1.4x TC). High-speed synchronized fill-flash.

I want to interpret the natural world and our links to it. It’s driven by the belief of many world-class scientists that we’re in the midst of an extinction crisis… This time it’s us that’s doing it.–Frans Lanting

Hunting: Gallinule Style

Posted November 30, 2013 by Elisa Lewis

Female_Purple_Gallinule_hunting_aquatic_leaf_beetle — An aquatic leaf beetle, *Donacia* sp., tries (and ultimately fails) to escape the Purple Gallinule jaws of death.

I’ve been looking forward to putting this post together since I took these photos on the first day of fall this year. I just love it when all the tumblers fall in place and I capture an interaction that tells a story. I was camped out along the banks of Elm Lake at Brazos Bend State Park watching Purple Gallinules methodically turning over what seemed like each and every lotus leaf in their paths. Grab; step; fold; hold. Grab; step; fold; hold. Again and again, they applied the technique as they criss-crossed back and forth across the carpet of lotus leaves. I assumed they were hunting but, for what? Strangely enough they ignored the aquatic snails conspicuously stuck to the undersides of the overturned lily pads. The snails looked pretty good to me, and snails are on the typical Purple Gallinule menu – along with seeds, insects, crustaceans, fish, eggs, and marsh bird nestlings (!) – but they passed on the snails. Not even a “no thank you” helping. It wasn’t until I was able to look at my photos closely that I was able to identify the special of the day – aquatic leaf beetles.

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Over a period of about an hour and a half, I captured 17 unique predator-prey interactions and nine of those involved Donacia, the aquatic leaf beetle. Two involved fish and the remaining four menu items – unidentified. This juvenile Purple Gallinule found its beetles either sandwiched between overlapping lotus leaves or nestled within enrolled emergent lotus leaves. I also saw the gallinule peek inside the rolled up leaves presumably checking for beetles before ripping a small hole in the side to extract the snack. (I’ll post that series later.)

Female Purple Gallinule peeking under a lily pad — Come out, come out, wherever you are! An immature Purple Gallinule looks for aquatic leaf beetles under American Lotus leaves on Elm Lake at Brazos Bend State Park, Texas.

Green Darners: Bird Food that Migrates

Posted October 5, 2013 by Chris Cunningham

Anax-Pair-CCunningham — *Mated Pair of Green Darner Dragonflies (Anax junius).* Dragonfly reproductive biology is rather brutal. The male dragonfly (right) grasps the the female (left) by the head while she lays eggs. This ensures that the eggs he fertilized have a chance at development–rather than being forcibly removed by another male. This “guarding” behavior can lead to damage to the female’s exoskeleton. Photo taken on 9/28/13 at Fennessey Ranch, South Texas. Canon EOS 7D/600mm f/4L IS (+1.4x TC). Natural light.

I have noticed a large up-tick in the number of Green Darners (Anax junius) around the Texas Gulf Coast. This no surprise as Green Darners migrate from as far north as Alaska to as far south as Panama during the fall. The details of Green Darner migration across North America are sketchy, but many millions fly south during fall with their avian predators. Why some Green Darners migrate and others stay put is a mystery, but the north-south migration is intergenerational as the reproductive adult typically only lives for an estimated 4-7 weeks. On an individual basis, telling a migrant from a resident is generally not possible.

For a bird photographer, the waxing and waning of abundance of adults of different dragonfly species means that I get to shoot birds preying on different species of dragonflies throughout the spring, summer, and fall. For dragonflies, it seems likely that emergence (molting into the flying adult from the aquatic larval form) and mating are two times of special vulnerability to avian predation. In the case of the former, the dragonfly must sit motionless on vegetation for hours while the wings extend and harden. In the latter case, the male and female insects are attached, thus presenting a larger and slower target for predatory birds.

In any case, such temporal variation in prey abundance adds a fascinating dimension to nature photography . . . .

Little-Blue-with-Anax-CCunningham — *Little Blue Heron with Male Green Darner Dragonfly (Anax junius)* at Brazos Bend State Park, Texas. This bird grabbed dragonfly after dragonfly from vegetation. Whether or not these insects had just emerged or were migrants must remain a matter of speculation–but one day there was suddenly a huge number of Green Darners in the park. Canon EOS 600mm f/4L IS (+1.4x TC). Photo taken in late September. High-speed synchronized fill-flash.

Late Summer and Early Fall: It’s Berry Time for Migrating and Resident Birds!

Posted September 21, 2013 by Chris Cunningham

Hackberries and Spiders: A first fall male Baltimore Oriole hunts spiders on fruit-laden hackberry tree. Photo taken in late September at Anahuac National Wildlife Refuge. — *Hackberries and Spiders:* A migrating first fall male Baltimore Oriole hunts spiders and forages berries on a fruit-laden hackberry tree. Photo taken in late September at Anahuac National Wildlife Refuge. Note the remains of berries on the bird’s beak. Canon EOS 7D/500mm f/4L IS (+1.4x TC). Natural light.

One of the highlights of birding during the summer/fall transition is witnessing the explosion of fruits that come into season at this time. Last Saturday (9/14) I visited the Edith L. Moore Nature Sanctuary in west Houston. Even though the drought had caused many of the plants to droop and otherwise appear stressed, the understory was bursting with ripe beautyberries and pokeberries, and greenbrier vines laden with shiny orange berries climbed to the heights everywhere. Yaupon berries were still green or just beginning to turn red and will provide food for birds later in the fall and winter.

Beauty berries at Edith L. Moore Nature Sanctuary, Houston. — Beautyberries (*Callicarpa* sp.) at Edith L. Moore Nature Sanctuary, Houston. Beautyberries are a favorite of American Robins, Cedar Waxwings, and Northern Mockingbirds. Canon EOS 7D/100mm f/2.8L IS macro. High-speed synchronized flash.

The beautyberry and pokeberry patch was thick with frugivorous American Robins and Northern Mockingbirds. A few Blue Jays and Northern Cardinals were also hanging around the patch. Mockingbirds were plucking greenbrier berries from vines high in the crowns of trees. On Wednesday (9/18) I returned to find that many of the berries had already been stripped from the plants. But, never fear, in the shadier areas the next crop of ripening berries was waiting in the wings.

For the birder, some plants with ripe berries are worth staking out. Hackberry trees, for example, are a favorite among primarily insectivorous birds (like warblers), as well as those mainly interested in fruits. A hackberry tree is a mini-ecosystem–fresh and decaying fruit attracts insects. Spiders hunt the insects from webs and the nooks and crannies of rolled-up leaves, and warblers grab the spiders. Ecosystems: they work!

A Black-throated Green Warbler hunts insects and spiders on a hackberry tree. — *A Black-throated Green Warbler* hunts insects and spiders on a hackberry tree in late September. Black-throated Green Warblers will eat berries during the non-breeding seasons, but on this day it was all about finding insects and spiders hiding in rolled up leaves. Photo taken at Ananhuac National Wildlife Refuge, Texas. Canon EOS 7D/500mm f/4L IS (+1.4x TC). Natural light.

O Autumn, laden with fruit, and stained
With the blood of the grape, pass not, but sit
Beneath my shady roof; there thou may’st rest,
And tune thy jolly voice to my fresh pipe;
And all the daughters of the year shall dance!
Sing now the lusty song of fruit and flowers.

–William Blake

Hummingbird Travelog Part 1: The Oasis Effect

Posted September 14, 2013 by Elisa Lewis

Juvenile male Rufous Hummingbird in flight — Juvenile male Rufous Hummingbird making a play for an open feeder spot at the Franklin Mountains State Park bird blind. Canon EOS 7D/500mm f/4L IS (+1.4x TC). Natural light. 7.26.2013.

All systems in nature seek the lowest available energy state. This is a concept that my students could always grasp on a personal level. (Substitute “teenagers” for “all systems in nature” in the first sentence. See what I mean?) Human nature, like the rest of nature, tends to follow the path of least resistance. Hummingbirds are no different.

Consider the droves of hummingbirds attracted to sugar-water feeders. Well-kept feeders are an easy alternative to foraging, and field studies show that when nectar (or nectar substitute) sources are super abundant, high metabolic cost territorial activity decreases. Feeders are the path of least resistance for hummingbirds.

Human interest in hummingbirds and the resulting dedication to supplementing their diet has impacted their biogeography. Hummingbird banding data support the idea that feeders (along with native gardening practices) are the reason that overwintering hummingbird populations have expanded along the Gulf Coast after first migrating into Mexico in the fall. Feeders and native plantings also contribute to the so-called “oasis effect” observed in exurban developments in the arid southwest where increasing numbers of hummingbirds (among other birds) in resource-poor terrain take advantage of supplemental food, shelter, and water resources.

Hovering male Calliope Hummingbird drinking from a sugar-water feeder — Male Calliope Hummingbird taking advantage of the sugar-water feeders at the Franklin Mountains State Park bird blind in July. Canon EOS 7D/500mm f/4L IS (+1.4x TC). High-speed synchonized flash. 7.26.2013.

On our recent summer desert birding road trip, we found the Franklin Mountain State Park feeders buzzing madly with hummingbirds. Especially welcome was the opportunity to get close-up views of Calliope Hummingbirds – thought to be the smallest long-distance avian migrant in the world – on their 5,000 mile southern journey to Mexico from the northwestern US and Canada.

For Calliopes, fall migration starts early. Sources report typical Calliope departures from northwest locales in late August. But wait, it was late July and they were already in Texas … Was this early arrival due to a natural seasonal shift or could it just have been the oasis effect?

I hear like you see — like that hummingbird outside that window for instance.

— Ray Charles

Waders Will Continue to Surprise the Attentive Birder with Diverse Hunting and Fishing Strategies

Posted August 31, 2013 by Chris Cunningham

Crouching Green Heron at Brazos Bend State Park, Texas — *Green Heron Crouching Low on American Lotus Leaf.* Perhaps to remain invisible to fish swimming near the surface, this Green Heron rested on its toes and feet close to water level. Canon EOS 7D/600mm f/4L IS (+1.4x TC). Elm Lake, Brazos Bend State Park, Texas, natural light.

Even after several years of frequent wader-watching at Brazos Bend, these birds continue to reveal new tricks in their extensive repertoire of hunting strategies. Recently I observed a Green Heron resting on an American Lotus leaf. Green Herons are common at Brazos Bend, and they can often be seen hunting and fishing from aquatic vegetation and partly submerged logs. Birds usually stand on their toes. What was interesting in this case was that the bird was crouching low, resting on its toes and feet (digits and tarsometatarsi, respectively) near the edge of the plant. The bird peeked over the edge of the leaf, studied the surface of the water, and every so often shot out its long neck and snatched a small fish from near the surface of the water. Was the bird hiding from the fish below or studying the fish-produced ripples on the surface of the water, or both? In any case, it was fun to watch.

Nitpicking Green Heron at Brazos Bend State Park, Texas — *Nitpicking Green Heron* at Elm Lake, Brazos Bend State Park, Texas. Canon EOS 7D/600mm f/4L IS (+1.4x TC).

Waders are great preeners, constantly cleaning and fussing with their feathers. Usually preening means that the action is over for a while–so the photographer interested in capturing hunting and fishing scenes may just as well move on to another bird. However, this summer I caught a Green Heron using the brilliant sunlight to find snacks on its wings. The bird, shown above, held its wings up to the sun. The light streaming through the feathers presumably allowed the bird to spot parasites, pick them off, and eat them. Pretty neat: dining at home!

Snowy Egret bubbling and crouching at Brazos Bend State Park, Texas — *Snowy Egret Bubbling and Crouching* at Brazos Bend State Park, Texas. This bird is blowing bubbles and making ripples that seem to attract prey, including fish. In this case, the egret is crouching with one foot on a submerged log, the other on the bottom. Canon EOS 7D/600mm f/4L IS (+1.4x TC). High-speed synchronized fill-flash.

This summer at least one Snowy Egret spent a lot of time blowing bubbles (and making ripples). This bubbling clearly activity attracted a variety of prey, mostly small fish, that were quickly snapped up. Once, the bubbling attracted something that was too big to handle. I saw a disturbance in the water, and the bird ran away squawking–perhaps a big gar or bowfin came slithering up? I also caught a bubbling Snowy Egret resting on its toes and feet on a log (shown below).

A Snowy Egret rests on its tarsometatarsi to hunt at Brazos Bend State Park, Texas — *Crouching Snowy Egret.* This Snowy Egret rests on its feet and toes to hunt via bubble-blowing at Brazos Bend State Park, Texas. A few bubbles can still be seen on the surface of the water. Canon EOS 7D/600mm f/4L IS (+1.4x TC).

Although wary and uncooperative photographic subjects, Cattle Egrets are common in the grassy areas–and occasionally at the waters’ edge–at Brazos Bend. One day I saw a group of half a dozen Cattle Egrets stalking through the brush like a gang of young toughs grabbing dragonflies and spiders and whatever else moved. They strolled along together, a few feet apart, though the understory vegetation. If one bird flushed or disturbed a prey item an adjacent bird got a crack at it. Grasshoppers, spiders, dragonflies, maybe the occasional frog–down the hatch! Co-operation: it works!

Cattle Egret at Brazos Bend State Park, Texas — *Cattle Egret Hunting Dragonflies and Spiders* at Brazos Bend State Park. Photo taken at Pilant Slough. Canon EOS 7D/600mm f/4L IS (+1.4x TC). High-speed synchronized fill-flash.

There’s a fine line between fishing and just standing on the shore like an idiot.—Steven Wright

Summer Birding in Portal, Arizona and Environs

Posted August 24, 2013 by Chris Cunningham

Broad-billed Hummingbird at Cave Creek Ranch, Arizona — *Male Broad-billed Hummingbird* at Cave Creek Ranch, Arizona. The feeders around the main office were swarmed with Broad-billed, Black-chinned, Blue-throated, and Broad-tailed Hummingbirds. The Broad-billed Hummingbird is primarily a Mexican species, its range barely extending into the Southwest U.S. during summer. Canon EOS 7D/600mm f/4L IS (+1.4x TC). High-speed synchronized fill-flash.

Portal, Cave Creek Canyon, and the South Fork of Cave Creek of southeast Arizona are magic words to birders. Southeast Arizona provides habitats for about one-half the species of birds present in North America north of the Mexican border. A variety of biological, geological and topographic factors have conspired to make this so. Most important, perhaps, is that this area lies at the northern extremity of the ranges of what are essentially Mexican species, so birds of the Southwest U.S. can be seen alongside more exotic subtropical ones.

Topography is also an important part of the story. Approaching Portal, Arizona from Rodeo, New Mexico you travel through the rocky Chihuahuan Desert, slowly climbing in elevation. Cactus, agave, and mesquite are scattered around. Near Portal, Arizona you start to encounter cottonwoods and other tall trees, and by the time you are driving Forest Road 42 toward South Fork Cave Creek you are in a stunningly diverse riparian forest with pine, sycamore, oak, maple and others: this is a Madrean pine-oak forest. The topographic map above gives some sense of the changes encountered while traversing the Portal area.

Vista Point, near Cave Creek, Arizona — *A View from the Vista Trail*, Coronado National Forest, Arizona showing a pine-oak forest extending up to the bare volcanic rock of an arid canyon. The distribution of plants and animals varies dramatically by elevation and distance from water. Canon EOS 7D/Tokina 11-16mm f/2.8. Natural light.

Scattered around the forest floor in summer are trumpet-shaped pink to coral to red flowers–hummingbird food plants. At one point, I turned and came face-to-face with a Magnificent Hummingbird. The bird hovered in front of my face for a full second, looked me over, and shot off into the forest, perhaps in search of nectar. At lower elevations I noticed Scarlet Bouvardia (Bouvardia ternifolia) and Scarlet Sage (Salvia coccinea), giving way to unfamiliar flowers at higher elevations. The botany of this area will take years to comprehend . . .

Yellow-eyed Junco at Barfoot Park, Arizona — *Yellow-eyed Junco* at Barfoot Park, Coronado National Forest, Arizona. Yellow-eyed Juncos are another primarily Mexican species. This bird nests in coniferous (or Madrean pine-oak) forests at elevations of 5,900-8,200 ft and eats mostly seeds (in cool weather) and arthropods (in warm weather). Barfoot Park is at an elevation of 8169 ft and is dominated by lofty ponderosa pines. Canon EOS 7D/600mm f/4L IS (+1.4x TC). Natural light.

Likewise the incredible diversity of summer bird life, especially flycatchers, will take years to fully appreciate. With further study and (at least) annual pilgrimages to this area, I hope to become familiar enough with the natural history of the area to use season, elevation, and habitat to identify birds and help understand their activities. In any case, the Cave Creek area is certainly one of the crown jewels of American birding.

Fast is fine, but accuracy is everything.― Wyatt Earp

Birding the Desert Southwest in Summer: Franklin Mountains, West Texas to Cave Creek Canyon, Arizona

Posted August 3, 2013 by Two Shutterbirds

Male Calliope Hummingbird at Franklin Mountains State Park, Texas — *Male Calliope Hummingbird* at Franklin Mountains State Park, West Texas. Canon EOS 7D 500mm f/4L IS (+1.4x TC). High-speed synchronized fill-flash.

We just returned from a fantastic road trip across West Texas, New Mexico, and southeastern Arizona. Along the way we stopped at four places, and each of these stops will serve as the basis for a dedicated post or two in the future. In the meantime, here are some highlights.

The first stop was the observation blind at the Tom Mays Unit of Franklin Mountains State Park, just north of El Paso, Texas. We have visited this locale before during other seasons. Sparrows and finches dominate during the cooler months (take a look here at our sparrow collection), but during the summer, hummingbirds rule! The air was thick with Black-chinned, Rufous, and Calliope Hummingbirds. Oodles of Calliope Hummingbirds in the middle of summer in Texas? Yes–and that will be a future post!

Cactus Wren at Cave Creek Ranch, Arizona — *Cactus Wren* at Cave Creek Ranch, Arizona. Canon EOS 7D/600mm f/4L IS (+1.4x TC). High-speed synchronized fill-flash.

After the Franklin Mountains came Cave Creek Canyon in the Chiricahua Mountains of extreme southeastern Arizona. This is the first time we visited Portal and environs in summer, and it was amazing. Just coming to grips with the botany and entomology in this arid Garden of Eden would take a lifetime. The birding was also phenomenal, and we added several species that can only be seen in southeast Arizona (or perhaps the southern extremities of New Mexico and/or Texas) within the U.S. including Blue-throated and Broad-billed Hummingbirds, Sulphur-bellied Flycatchers, Brown-backed (a.k.a. Strickland’s or Arizona) Woodpeckers, and Yellow-eyed Juncos, among others. We look forward to writing much more about Cave Creek in the future!

On the way back, we took a “minor” detour through Roswell, New Mexico to scope out Bitter Lake National Wildlife Refuge. On the way, we read about a colony of Burrowing Owls that live in a Black-tailed Prairie Dog town located in Roswell’s Spring River Park and Zoo. We couldn’t resist–even though we were bleary-eyed from seven hours in the car.

At this park, you could make the case that the prairie dogs are captive animals, although they routinely burrow under the park wall and could walk away if they wanted. The owls, however, are wild animals that stay in this prarie-dog town in close proximity to humans of their own volition–although their choices are limited. About 99% of prairie dogs have been exterminated in the U.S., and the owls rely on the burrows of these rodents. Another future post!

Burrowing Owl at Roswell, New Mexico — *Burrowing Owl at Twilight,* Roswell, New Mexico. Canon EOS 7D/600mm f/4L IS (+1.4x TC). Natural light: the huge eyes and *tapetum lucidum* (and resulting eyeshine) of these birds make flash photography problematic.

Finally, we stopped at Bitter Lake National Wildlife Refuge, a major wintering ground for waterfowl along the western extremity of the Central Flyway, and reportedly one of the best areas to see dragonflies in the U.S. during the hot months: just what we need to fuel our nascent interest in dragonfly photography. This sun-baked desert oasis, no doubt, will warrant future mention on Twoshutterbirds. We are already planning future visits to the desert Southwest while we eagerly await the fall cool down along the Texas Gulf Coast and the beginning of the fall migration.

Female Eight-spotted Skimmer Dragonfly at Bitter Lake NWR, New Mexico — *Female Eight-spotted Skimmer Dragonfly* at Bitter Lake National Wildlife Refuge, New Mexico. Canon EOS 7D/500mm f/4L IS (+1.4x TC). High-speed synchronized fill-flash.

“I was born on the prairies where the wind blew free and there was nothing to break the light of the sun. I was born where there were no enclosures.”–Geronimo

Birding by Camera | Adventures in Nature Photography