Louisiana Waterthrush with Fly Larva at Pilant Slough, Brazos Bend State Park, Texas. The caterpillar-like arthropod appears to be a large horse fly larva, but I invite comments from anyone who knows better. Canon EOS 7D/500mm f/4L IS (+1.4x TC). Natural light.
Photographing birds is often not easy, and getting them in the act of hunting can be a special challenge. But even after you have the image, the work may not yet be done as prey items can be difficult to identify. Vertebrate prey items (particularly fish) can be challenging, but invertebrates, especially larval forms, can be maddening when your invertebrate biology courses were twenty-plus years ago! The rewards of such research, though, are great. Identifying prey puts you in tune with the bird’s life: Now you know what they’re looking for when you see them poking around in particular habitats, at particular times of the year. For me, this is one of the more interesting aspects of birding, one made possible by the camera.
Female Hooded Oriole with Katydid at Santa Ana National Wildlife Refuge, South Texas. The insect appears to be a spoon-tailed short-winged katydid (Dichopetala catinata), or related form, but I invite comments from anyone who knows better. Canon EOS 7D/600mm f/4L IS (+1.4x TC). High-speed synchronized fill-flash.
Our retinas and brains have been wired by a hundred million years of evolution to find outlines in a visually complex landscape. This helps us to recognize prey and predators.—Seth Shostak
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.
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. 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
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.
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.
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.
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?
Mallard Duckling in Olympic National Park, Washington. Canon EOS 7D/500mm f/4L IS (+1.4x TC). Natural light.
Late spring and early summer can be a frustrating time for birding given the relatively low avian diversity, the bugs, and the traffic headaches/low-quality encounters as the Summer People emerge from their pods. But there are ducklings around! And ducklings are fun!
Several things always strike me about ducklings (besides how cute they are). First, they face some significant challenges . . . such as being on a lot of menus.
Muscovy Ducklings in Hermann Park, Houston, Texas. Canon EOS 7D/100-400mm f/4.5-5.6L IS. Natural light.
I remember as a child in Minnesota being horrified to learn that muskellunge (a type of large aggressive pike known to Midwesterners as “muskies”) eat ducklings. I remember standing on a dock and staring down into the water and seeing a bunch of these black and green striped killers on a stringer and thinking no more ducklings for you! Down here in Texas it’s alligators, snapping turtles, gar . . . and rat snakes. There’s no question about it, wild ducklings live in a dangerous world.
Another striking thing about wild ducklings is that many species look so much alike. Domestic ducklings, like Call Ducklings, are often all yellow, but sometimes show a variety of black markings. Apparently being yellow with black stripes and blotches makes for a perfect duckling in a wilderness setting.
A dark-colored top (with some disruptive stripes or spots) may camouflage the ducklings from predators from above, while the brightly-colored underside may not be as visible to aquatic predators viewing them from below against the sky. In any case, a counter-shaded black and yellow pattern certainly makes for a perfectly charming wild duckling.
Black-bellied Whistling-Duck Family at Elm Lake, Brazos Bend State Park, Texas. Canon EOS 7D/600mm f/4L IS (+1.4x TC). Natural light.
I think it would be terrific if everybody was alike.—Andy Warhol
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, 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 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, 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
White-faced Ibis With Bulb or Tuber Being Shadowed by Common Moorhen at Pilant Lake, Brazos Bend State Park, Texas. These tubers or bulbs are apparently worth fighting over. This sneaky little Common Moorhen stole the poor Ibis’s snack! Canon EOS 7D/600mm f/4L IS (+1.4x TC). Natural light.
Despite often gloomy and dismal weather and optical conditions, the marshy south flank of Pilant Lake near the observation tower at Brazos Bend State Park, Texas has been an exciting place for birders this winter. In addition to the usual suspects present during winter, American Pipits, Wilson’s Snipes, American Bitterns, Song Sparrows, Least Sandpipers, and a Solitary Sandpiper have been spotted in the vicinity. What’s more, interesting bird behavior and interactions have been common lately, and I’ve made inter- and intra-species conflicts and confrontations the theme of my photos for this post. There are, for example, so many Wilson’s Snipes around that they’re getting into each other’s business: violations of personal space result in displays as shown below.
Shall We Dance? Wilson’s Snipe Confrontation at Pilant Lake, Brazos Bend State Park. Canon 7D/600mm f/4L IS (+1.4x TC). Natural light.
The south side of Pilant Lake is also one of the best spots to photograph wader hunting behavior that I know. This winter has been no exception. Two weeks ago a Great Blue Heron is reported to have taken a large siren (Siren intermedia), a very large salamander, from immediately north of the observation tower. As a result, I spent a few hours stalking a Great Blue in that area the day after the report, but I only saw the bird catch frogs. Maybe next time.
Great Blue Heron With Frog at Pilant Lake, Brazos Bend State park, Texas. After repeatedly pecking this unfortunate frog, the heron ultimately rejected it and walked off. Canon EOS 7D/600mm f/4L IS (+1.4x TC). High-speed synchronized fill-flash.
The passions are the same in every conflict, large or small.—Mason Cooley
Least Bittern with Fish (Darter?) at McFaddin National Wildlife Refuge, Texas. A prized sighting not because Least Bitterns are rare, but because they are secretive. They may be quite common . . . it’s hard to tell. Canon EOS 7D/500mm f/4L IS (+1.4x TC). Natural light.
Of the heron, egret and bittern family, the two species of North American bitterns are the most secretive. When spotted, their slow, precise, almost machine-like stalking behavior is mesmerizing to watch. Sometimes bitterns seem acutely aware of the photographer’s every breath and muscle-twitch, and sometimes they are completely oblivious to observers and go about their hunting as if they alone occupied the planet.
Least Bitterns summer in the eastern U.S., including the Gulf Coast, and American Bitterns winter along the Gulf Coast—so for the Texas birder, the possibility (at least) exists for seeing bitterns throughout much of the year.
Beauty Shot: Least Bittern at McFaddin National Wildlife Refuge, Texas. Sometimes even the most secretive birds cooperate. Canon EOS 7D/500mm f/4L IS (+1.4x TC). Natural light.
Of the two bittern species, the American Bittern has the more cryptic coloration, I think. Many times I have had to double-take when I first noticed one–especially if the bird had adopted its neck-straight-up “I’m-a-clump-of-marsh-vegetation pose.” Least Bitterns are also difficult to see among marsh vegetation and have been known to sway back and forth to mimic the gentle motion of vegetation tussled by the wind. These are clearly creatures that do not want to be noticed.
American Bittern Out in the Open at Pilant Lake, Brazos Bend State Park, Texas. Canon EOS 7D/500mm f/4L IS (+1.4x TC). Natural light.
It’s hard to recommend a place to see bitterns in the Houston area. The south side of Pilant Lake at Brazos Bend State Park is the most reliable spot to see American Bitterns I know. But in many visits to that area, I’ve only seen a Least Bittern once. And that’s how I would characterize my experience with Least Bitterns: I’ve seen them many places once.
Calls of both species of bitterns are distinctive enough to know when they’re around, even if they are invisible, especially the Least Bittern’s rather monkey-like (to my ear) coo-coo-coo. Least Bitterns are also easy to spot in flight, given their heron-style of flight and rufous markings—but once they’re back in the reeds, it’s good-bye, Charlie!
Move along! Move along—nothing to see here! What you normally get in the way of bittern photos: cryptic American Bittern at Brazos Bend State Park, Texas. This bird soon slowly turned and skulked off into the marsh. Canon EOS 7D/500mm F/4L IS (+1/4x TC). Natural light.
Don’t wait to be hunted to hide, that was always my motto. —Samuel Beckett, Molloy
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. 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.
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
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.)
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.
Gaping Snowy Egret at Elm Lake, Brazos Bend State Park, Texas. This bird spent the morning on the shore shadowing Pied-billed Grebes as they hunted. Canon EOS 7D/600mm f/4L IS (+1.4x TC). Natural light.
Snowy Egrets are known for shuffling their bright yellow feet in the shallow water to scare up dinner. This summer I also caught one employing a bubble-blowing hunting technique to attract invertebrates and small fish.
On Saturday (11/2) at Elm Lake, Brazos Bend State Park, Texas I noticed another Snowy Egret fishing/hunting strategy that was new to me–and one that also involves scaring up prey. The egret shown above tracked Pied-billed Grebes back and forth as they chased fish and crawfish in the shallows, perhaps 3-4 feet from the shore. Likely fish and invertebrates scatter as grebes go swimming past–and likely this egret was making use of this to pick off prey responding to the grebes. During this shadowing behavior, the egret was quite good at predicting just where the grebe would surface. Perhaps the grebes were visible, at least sometimes, from the egret’s vantage point? Or was this wader ESP? In any case, the egret would often dash to a position on the shore closest to where the Grebe would suddenly emerge from the water.
Commensalism, a symbiosis in which one organism benefits and another is largely unaffected, is likely the label an ecologist would place on the above relationship. But could it be mutalism? Did the grebes benefit from the presence of the egret? Perhaps the egret could have revealed the presence of predators lurking in the shallows or the weeds? Did the grebes have one eye out on a friend on the shore who might signal (through behavior) the presence of an alligator lurking on the shore otherwise undetected? Or a nasty old alligator gar floating, log-like in the shallows? Perhaps the egret chased prey items (like plump juicy frogs) from the shoreline into the water? Food for thought.
Pied-billed Grebe with Red Swamp Crawfish at Elm Lake, Brazos Bend State Park. Note the large blob of water frozen in mid-air by high shutter speed as this grebe engaged in an epic struggle with a crawfish one-third its size. Canon EOS 7D/600mm f/L IS (+1.4x TC). Natural light.
Competition has been shown to be useful up to a certain point and no further, but cooperation, which is the thing we must strive for today, begins where competition leaves off.–FDR
