Courtship consists in a number of quiet attentions, not so pointed as to alarm, nor so vague as not to be understood.—Laurence Sterne
Lafitte’s cove is often thought of as a mecca for migrant songbirds, but it’s usually a good idea to check the margins of the lakes for shorebird and wader activity. On one recent visit (4/16), we were lucky to see the courtship ritual of the Black-necked Stilt. Although similar to that of the closely related American Avocet (which we have documented previously), the Black-necked Stilt ritual encompasses a number of different, albeit equally charming, behaviors.
The male first approaches a female that has signaled her readiness by adopting a horizontal posture. The male nods.
He then stirs the water with his beak . . . .
The male strolls to the female’s other side . . . .
Here, he again stirs up the water with his beak . . . .
The male then mounts the female and consummates the relationship . . . .
After copulation, the male descends. He then places his wing over her body and crosses his bill over hers . . . .
The pair then promenades together for a few paces. They are now together . . . for at least this breeding season.
Last week we didn’t see many Neotropical migrant songbirds. The weather was incredible . . . but maybe that was the problem. With crystal clear skies and a consistent wind out of the south, i.e. a tailwind, the trans-Gulf migrants may have simply blown past the Coast and the usual migrant traps. What’s good for birds, is bad for birders.
What’s more, dry weather means that there haven’t been many arthropods around other than caterpillars and a few flies, mosquitos, dragonflies, and spiders. So there really hasn’t been much of a reason for birds to stop if exhaustion or thirst wasn’t a problem. At Lafitte’s Cove on 4/8 I saw a few Ruby-throated Hummingbirds and one vireo or warbler (I saw only a creamy yellow underside through the canopy)—a terrible showing for April at a Gulf Coast migrant trap.
Some stormy weather moved into the Gulf Coast throughout this week. On Tuesday (4/11), for example, a major front swept down mid-day and looked the perfect set-up for a fallout. Sadly, I watched the atmospherics on radar from work, trapped and unable to get into the field. But yesterday (4/14) was also bad at Lafitte’s Cove. I only saw a few hummers, a Black and White Warbler, a Hooded Warbler, a Bronze-headed Cowbird, and a White-eyed Vireo. In addition to these, Elisa saw two Tennessee Warblers. Not great.
In any case, hope springs eternal, and we’ll give the Coast the old college try again this weekend! One of these days . . . .
Birds’ love and birds’ song
Flying here and there . . . . Spring, Alfred Lord Tennyson
As of this writing, we are still waiting to see a significant number of migrant songbirds and shorebirds. We are, however, watching spring unfold in other ways. New growth is sprouting up across the landscape, and will soon overwhelm the dead plant life of the previous growing season.
Flashes of wildflower-color can be seen scattered around. Insect life is starting to awaken—although, mercifully, the mosquitos have been strangely modest in number.
Everywhere caterpillars can be seen crawling around, and everywhere birds are gobbling them up! If the birds had their way, there would be no moths or butterflies!
On our last visit to Lafitte’s Cove—despite being in April–we saw no wood warblers (or any other migrant songbirds for that matter) at all. A lone Brown Thrasher called from the thicket. Disappointed, we headed over to East Beach . . . .
Here, we saw a few migratory shorebirds. Dunlins and Western Sandpipers were around and beginning to transition into breeding colors. Snowy and Wilson’s Plovers (and Killdeer) were scooting around along tidal channels and on the supratidal flats. One of these days, one of these days . . . the mottes and beaches are going to throng with avian life. Here’s to being there when it happens!
What we achieve inwardly will change outer reality. –Plutarch
This week on Galveston, Common Loons could be seen in many stages of transitional plumage. Every bird looked slightly different. All the birds I saw had some degree of spotting on the wings, and so lacked the brown, scalloped pattern of nonbreeding wing plumage. I saw one bird with a shaggy mane of pin feathers (Thanks to S.M. for pointing out this bird!) and one bird in almost complete breeding colors—only a stray feather here or there needed to be pigmented.
Many birds were engaged in hunting behavior much of the time. I saw fish, crabs, and a single mantis shrimp (Squilla empusa) being taken. This is clearly the time of year to be gorging and fattening up. It’s a long way back to Canada and environs for the breeding season! A good deal of preening was also going on, likely related to molting and keeping feathers in shape for the big trip ahead. Two birds had already pair-bonded and spent a significant amount of time together–another reminder that breeding in birds is often a process that unfolds in many stages over much of the year.
Life is one long process of getting tired.–Samuel Butler
The house is in shambles, and the yard looks like a post-apocolyptic wasteland (Thanks, sod webworm moth larvae!) so we’re takin’ a break! Not to worry, we’ll be back on the ball soon!
Feet, what do I need you for when I have wings to fly?—Frida Kahlo
Among extant birds, grebes have a unique method of foot propulsion. There are other foot-propelled divers, loons, for example, but these birds have significant webbing between the toes. The birds with webbed toes push themselves forward against the drag force of water. Grebes, on the other hand, have separate toes with stiff, collapsible asymmetrical lobes on each side. The lobes on the inside are larger than those on the outside. Grebes are also unusual in that their relatively short femora (thigh bones) are oriented perpendicular to the long axis of the body, and the toes beat along a complex dorso-lateral to ventro-medial path, rather than parallel to the direction of the body’s forward motion.
The traditional interpretation of how grebes paddled through the water, and the one I was taught, is that the lobes of the toes would unfold during then power stroke to provide maximum drag to push against, and fold up to reduce drag on the the recovery stroke. A more recent interpretation is that the grebe foot acts like a (slotted) hydrofoil and provides a lift force that propels the bird forward from behind (Johansson and Norberg, 2001)–physically similar to the way in which a wing allows a bird or airplane to fly. The lift hypothesis has an immediate visceral appeal to me given the asymmetrical lobes of the toes—like the vanes of a flight feather. Lift is usually explained by elementary physics textbooks as the result of the Bernoulli principle, essentially the conservation of energy for a moving fluid. This explanation is not correct quantitatively. The true explanation likely involves the most terrifying of all physics concepts . . . turbulence . . . .
As a photographer on the surface, I haven’t been able to document the strange way in which grebes move through the water. Once and a while, when conditions were right, I have been treated to a glimpse of the legs in motion as in the image below. Swimming with grebes is one more activity to add to an already lengthy bucket list.
I mentioned at the opening that grebes were unique among extant birds. Hesperornithiformes, a group of toothed Cretaceous foot-propelled diving birds, are thought to have had a method of propulsion similar to grebes and to have possessed asymmetrically lobed individual toes. On a recent visit to the New Mexico Museum of Natural History in Albuquerque, I had the opportunity to study the feet of a life-sized model of Hesperornis regalis, the largest of these Cretaceous divers from the Kansas Chalk Sea. Reading the label . . . sure enough, reconstruction supervised by Dr. L. D. Martin, my late (paleo)ornithology professor, a gifted teacher with so many fascinating stories to tell about the lives of birds. . . .
While grebe-watching, I am always interested in seeing these birds return to the surface with prey. In my experience along the Gulf Coast, Eared Grebes rarely return to the surface with prey. After dozens of dives, I have seen only one small fish clamped in a beak. This means that grebes are either remarkably unsuccessful hunters (unlikely), or that they can swallow small prey underwater (likely). Pied-billed and Least Grebes can be seen with large prey on the surface like fish, crawfish, frogs, and dragonflies. Perhaps small prey may be easily swallowed in the submarine realm, whereas large prey items may need to be manipulated into an ideal orientation in the air. In any case, grebes are certainly among the most interesting subjects for study and observation. Elisa doesn’t have to ask me twice to go grebe-watching!
Reference
Johansson, L.C., and Norberg, U. M. L. Norberg. 2001. Lift-based Paddling in Diving Grebe. The Journal of Experimental Biology204: 1687-1696.
There is nothing either good or bad but thinking makes it so. –William Shakespeare
l know there is a great diversity of opinion on this subject, but my favorite kind of Texas photo-birding day is the day after a strong blue norther. The howling winds have died down, and the 40º sky is clear, but for a thin haze of cirrus clouds. This kind of day has been in very short supply for several years now.
Lately the weather has been wildly variable, with clear, cold days rare. This has meant having to make the most of a wide variety of lighting situations. The two cormorant shots above were taken under what I consider to be “bad” conditions. The sky was mostly cloudy with sunbreaks every few minutes leading to having to constantly chimp settings. When the sun emerged, it produced a blinding, muddy-yellow glare off the water’s surface. Because the fishing behavior documented was happening all around me, the sun was sometimes behind and sometimes ahead—making for an exciting morning of work!
Two recent visits to Offatt’s Bayou occurred during very different optical conditions. The upper grebe and loon immediately below were shot on a gloomy, gray, foggy morning. And the lower grebe and loon were shot on the same glorious, clear, bright morning about a week later at the same place.
This shooting locale (where 61st crosses Offfatt’s Bayou) has only recently become accessible again. Where rickety old docks used to stand, there is now a large raised cement viewing/fishing platform. The problem with the new platform is that it is too high, leading to an extreme shooting angle. The old situation was actually better, assuming you were willing to risk falling into the drink to get the shot. Alas, there’s really nothing to be done about the angle now—except to try and capture some interesting wave forms, colors, reflections, or textures from the surface of the water. Sometimes you have to take what you can get! Progress!
Birds are the most popular group in the animal kingdom. We feed them and tame them and think we know them. And yet they inhabit a world which is really rather mysterious. –David Attenborough
Frankly we haven’t gotten out much lately. This is a function of terrible weather and just plain exhaustion. The prospect of fighting traffic on a gloomly, humid 85° day in February hasn’t held much charm. Spending time indoors has led to combing through the photo archives and pining for past years in which we had a proper winter.
One of the things we would have been watching for this week, had we been outdoors, is the cooperative feeding behavior of American White Pelicans. Whenever I see these birds I stand in awe, just waiting for them to so something neat. Is there anything more majestic in American birding than a string of White Pelicans paddling in formation along the shallows searching for schools of fish?
American White Pelicans are known to cooperatively herd fish into the shallows by beating their wings. On Galveston, a fairly common sight is a line of White Pelicans suddenly forming a circle, beaks pointed inward, and gobbling up a school of fish (presumably).
Once the feeding frenzy is over, the birds turn around within their circular formation and reassemble into their line and continue paddling along peacefully . . . until the next school of fish.
Do the leg bands on my subjects ruin the shots for you? Me, I’m on the fence. Generally, Chris and I like to capture an idealized view of nature. We travel to state and national parks, wildlife refuges and nature preserves. We try to avoid shots that include fences, telephone poles, signs and roads. We like our birds au natural.
Nature provides a necessary respite from the human hustle—an escape from the man-made. Perhaps its true for you, too. Alas, the escape is an illusion. Even if we agree that humans are not the center of life on earth, we can’t deny that our influence is all but ubiquitous. How I crave those vistas without a trace of mankind—hard to find when you live in a metropolis. But, peering at the world through a camera lens takes me there. I suspend disbelief with a world view framed by the viewfinder and the silent still images that result.
So, when your subject sports a leg band, it kinda bursts the bubble.
Many agencies and organizations use bird leg bands for tracking purposes. For example, U.S. federal agency bands are for birds covered by the Migratory Bird Treaty Act, and state and provincial bands are for game birds (Galliformes). These banding programs are the reason we know what we know about the timing and scale of migration. Some agency programs, such as the North American MAPS (Monitoring Avian Productivity and Survivorship) Program, also produce data on the abundance, survivorship, and ecology of our continental land birds so the conservation community can better address conservation needs.
Chris and I sometimes romanticize the idea of time-traveling to the Pleistocene Epoch and experiencing the world at the dawn of man—before we altered the environment so discriminately in our favor. But here we are, in the Anthropocene, deeply intertwined with so many of our fellow species. And, unlike our fellow species, we know what we do. Conservation science through bird banding places our best foot forward to mitigate some of the damage, or at least learn how to considerately coexist.
So, putting aside all fantasies of a better past, I am compelled to celebrate these unwitting research subjects. They carry a burden for their well being—and so must we.
Life moves pretty fast. If you don’t stop and look around once in a while, you could miss it . . . . —Ferris Bueller’s Day Off (1986).
This is the time of year for sporadic frustrations. The unpredictable weather, sometimes nice, sometimes oppressive and freakishly warm, can easily become an excuse for doing nothing. Witnessing the saddening, nit-witted babbling of the media during the current silly season of politics doesn’t inspire great energy, either.
The birds and other organisms, however, are still out there and waiting to be observed and photographed! Biologically, there is quite a bit going on along the Texas Gulf Coast these days: Lately we haven’t been disappointed by East Beach or Fiorenza Park.
Our field work is undoubtedly the healthiest thing we do. It is a tragedy when nature lovers sit out a day in the field because of the malaise or exhaustion brought on by our absurdist era or the fear (or revulsion) of traffic jams and hordes of yahoos. This realization is why we drag ourselves out of bed early, even on our days off. We almost never regret getting out there, even if we had to talk ourselves into it in the first place!
You go to Brooklyn, everybody’s got a beard and plaid shirt. They may be able to tell each other apart, but they all look alike to me.–Don Lemon
Last glorious (but-too-windy-for-flash) Sunday we took a trip down to East Beach, Galveston Island looking for shorebirds and found all three species of the smallest Texas plovers in winter plumage.
The Semipalmated Plover breeds in the Arctic and winters along the Pacific, Atlantic, and Gulf Coasts. The Piping Plover has a complicated breeding range, but winters along the southern Atlantic and Gulf Coasts. Some Snowy Plovers reside year-round on the Texas Coast. The upshot of plover biogeography: All three of these cuties can (luckily) be found on the Upper Texas Coast in winter. But telling them apart can be a bit tricky, especially if they’re doing what they’re usually doing–skedaddling along the strand line looking for detritus and tiny infaunal invertebrates. This is termed the “run, pause, and pluck” style of foraging/hunting.
The legs are always the first place I look to identify a small plover. Snowy Plovers always have pinkish gray legs, in breeding and nonbreeding colors. Piping and Semipalmated Plovers have more colorful legs. In nonbreeding, Semipalmated Plovers have more yellowish legs, whereas Piping Plovers tend to have more orangish legs. The overall color palette is usually sufficient to separate Piping and Semipalmated Plovers: Semipalmated Plovers are mostly shades of brown and white and Piping Plovers are mostly shades of gray and white.
Snowy Plovers and Piping Plovers are not common birds—neither, for that matter, are Semipalmated Plovers. The Waterbird Society places a population estimate of around 25,000 for Snowy Plovers. Wikipedia places the number of “near threatened” Piping Plovers at around 6500. Semipalmated Plovers are the “common” small plover on Texas Coast, with an estimated 150,000 individuals worldwide—about as many humans in a smallish city. I wonder what the state of alarm would be if the global human population stood at 6500, 25,000, or even 150,000?
When an early autumn walks the land and chills the breeze
And touches with her hand the summer trees . . . . “Early Autumn,” Lyrics by Johnny Mercer
This week the sun passed the equator at high noon yielding a day with nearly equal darkness and light. But the important part: the days keep getting shorter. Birds are riding a blue train to the tropics in the hundreds of millions. We stand at the brink of the best of times, the longest stretch of cool, beautiful weather on the Texas calendar.
At least for now, the summer wind will be blowin’ in from across the sea–bringing patches of stormy weather. These atmospheric obstacles to avian movements will eventually cease as glaciers of cool breeze eventually bulldoze the sticky Gulf Coast air out to sea. On these frosty days the Gulf Coast, especially Galveston and the Coastal Bend, are a kind of Shangri-La. Can’t wait!