There is a time for many words, and there is also a time for sleep. –Homer
Soaring Swainson’s Hawk (Light Form), Fiorenza Park, Houston, Texas. Fiorenza Park is one of those places: You never know what is going to show up next. Canon EOS 7DII/600mm f/4L IS (+1.4xTC). Natural light.
The school year is winding down, and exhaustion has settled in—so we’re takin’ a break! Never fear, we’ll be back on the job in no time to share some more images and prose. We’ll have some neat nature photography projects to report on in the upcoming weeks and months–so stay tuned!
Juvenile Neotropic Cormorant with Threadfin Shad (Dorosoma petenense), Fiorenza Park, Houston, Texas. Now that warm weather is here, small fish can be found in the shallows—where the birds can gobble them up with ease. Time will tell how many different fish species we can document as prey items at Fiorenza. Canon EOS 7DII600mm f/4 L IS (+1.4x TC). Natural light.
Portrait: Whimbrel, Frenchtown Road, Bolivar Peninsula, Texas. Whimbrels will soon be gone: They nest in the arctic, mostly Alaska and around Hudson’s Bay. Frenchtown Road is the only dependable place to see them around here (that I know of). Canon EOS 7DII/600mm f/4 (+1.4x TC). Natural light.
When not chasing songbirds around during migration, we’re chasing shorebirds! In one sense, we’ve been less successful on the shorebird front than the songbird front this year. Specifically, this spring we saw two new warbler species (Blackpoll and Prairie, making a total of 38 species!), but we have yet to see a new shorebird. But it hasn’t been for lack of trying.
On the Way to the Arctic: Long-billed Dowitcher, Lafitte’s Cove, Galveston Island, Texas. This bird seems to have a “straight” supercilium, a “brick-red” cast to its feathers, a straight bill tip, and a relatively low-set eye (a “loral angle” of 19 degrees)—all Long-billed Dowitcher features. The loral angle was defined by Lee and Birch (2006). Canon 7DII/600mm f/4L IS (+1.4x TC). High-speed synchronized fill-flash.
As far as shorebirds (and waterbirds) are concerned, it really has been a “usual suspects” year. There are lots of Least and Western Sandpipers, Dunlin, dowitchers, and Semipalmated, Snowy, and Wilson’s Plovers around places like East Beach, Lafitte’s Cove, and Frenchtown Road (a favorite spot). And I can say that we’re getting better at identifying the trickier ones. Snowy, Semipalmated, and Piping Plovers are no longer look-a-likes in the field. I’ve even attempted to study up on dowitcher identification, one of the toughest challenges in North American birding. I feel more confident in my dowitcher identifications, but whether or not I’m right . . . .
Short-billed Dowitcher, Frenchtown Road, Bolivar Peninsula, Texas. This bird has an arcuate supercilium, an orangish cast to its feathers, and a relatively high-set eye—all Short-billed Dowitcher features. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
Finally, irrespective of which species you love most, the shorebird migration has two distinct advantages over the songbird migration. First there are almost never crowds. You can always find a lonely stretch of beach to bird alone. Second the beaches are almost always breezy enough to spare the birder the annoyance of mosquitos. Oh, yeah . . . and then there is the magnificent sea . . . .
Bathing Female Red-breasted Merganser, Frenchtown Road, Bovlivar Peninsula, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
Reference
Lee, Cin-Ty, and Birch, Andrew. 2006. Advances in the Field Identification of North American Dowitchers. Birding (Sept./Oct.): 34-42.
Never say there is nothing beautiful in the world anymore. There is always something to make you wonder in the shape of a tree, the trembling of a leaf. –Albert Schweitzer
Black-throated Green Warbler on Grapevine, Lafitte’s Cove, Galveston Island, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
As we get into May, the number of migrant songbirds appearing at the coastal migrant traps will begin to taper off. We found this spring to be a mixed bag of birding experiences. Due to south winds, we went long stretches without seeing much. Visits to the Corps Woods (Galveston), Smith Oaks, and Quintana did not bear much fruit. But there were a few really birdy days at Lafitte’s Cove, 4/23 and 4/30, for example. The mix of migrant songbird species here was a bit different from migrations of the recent past, though. We continue to hope for some good sightings before the spring migration effectively draws to a close . . . .
Tennessee Warbler with Grape Leaffolder Caterpillar (Desmia funeralis), Lafitte’s Cove, Galveston Island, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
As always at Lafitte’s Cove, there were quite a few Black-throated Green Warblers, but there were far fewer Black and White, Magnolia, and Hooded Warblers. We haven’t seen the “usual” unusual bids like Canada, Golden-winged, Bay-breasted, Blue-winged, or Kentucky Warblers (yet). We also only saw a handful of Prothonotary, Yellow, Palm, and Chestnut-side Warblers along with a single Ovenbird. On the other hand, Tennessee Warblers were around in large numbers.
Shy Bird: Palm Warbler on Grapevine, Lafitte’s Cove, Galveston Island, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
For the first time ever we saw Blackpoll and Cape May Warblers, and a single Prairie Warbler at Lafitte’s Cove. On 4/23 there were loads of Red-eyed Vireos (and at least one Black-whiskered Vireo), but we haven’t seen more than a handful of White-eyed Vireos, typically one of the most common migrants in the migrant traps. My impression is also that the number of other “common” brightly-colored songbirds like Indigo and Painted Buntings, Orchard and Baltimore Orioles, and Summer and Scarlet Tanagers has been down relative to recent years.
Male Orchard Oriole on Grapevine, Lafitte’s Cove, Galveston Island, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
But what really struck me at Lafitte’s Cove this year was the central role of the grapevines in attracting birds. The sanctuary at Lafitte’s Cove is an oak motte, a patch of trees on a slightly elevated section of a barrier island. As such, it is inherently a natural attraction for trans-Gulf migrants.
After several days at Lafitte’s Cove, however, it seems clear that the mere presence of the motte is not enough to explain why this spot is so much more attractive to birds than many other potentially similar localities.
I think the grapevines are the real draw. I witnessed many bird species eating grape leaffold caterpillars plucked from the grapevines. At times the vines were alive with foraging birds. For millennia, grapevines have been used as a symbol of blessing, and at Lafitte’s Cove they are a literal blessing to passing birds.
Building your own migrant trap? Plant some grapevines.
Quizzical Male Summer Tanager, Lafitte’s Cove, Galveston Island, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
Red-eyed Vireo with Dragonfly Caught in a Spiderweb, Lafitte’s Cove, Galveston Island, Texas. Why go dragonfly hunting when the spiders do all the work for you? Red-eyed Vireos and Tennessee Warblers have been abundant at Lafitte’s Cove this spring. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
Being the height of spring migration, we’re spending as much time as possible in the field. Weather conditions have determined that it will not be a great year for sighting Neotropical migrant songbirds along the Texas Gulf Coast (except for the fallout of 4/23!), but we have been seeing a few things of interest—notably Blackpoll Warblers, a Black-whiskered Vireo (Elisa only), and a Prairie Warbler at Lafitte’s Cove.
Male Blackpoll Warbler on Grapevine with Caterpillar, Lafitte’s Cove, Galveston Island, Texas. Blackpoll Warblers have been just behind Red-eyed Vireos and Tennessee Warblers in abundance this spring migration at Lafitte’s Cove. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). High-speed synchronized fill-flash.
We’ve also been seeing a variety of interesting predator-prey interactions we’ve not seen before. Catching songbirds in the act of grabbing prey in the dense thickets of a place like Lafitte’s Cove is the supreme challenge of bird photography. The split-second timing of the action, coupled with contrasty lighting conditions and a myriad of obstructions really test your resolve.
Slightly less formidable, though still not easy, is documenting waders and divers grabbing and eating prey. I truly love watching these birds going about making a living.
Where the Heck is My Shrimp Cocktail? Juvenile Neotropic Cormorant with Ohio River Shrimp (Macrobrachium ohione), Fiorenza Park, Houston, Texas. For a moment the bird lost track of the shrimp as it attempted to “flip” it into easy swallowing position. The Ohio River shrimp is one of the most common freshwater macroinvertebrates in North America—but try getting a shot of a bird eating one! Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.Juvenile Neotropic Cormorant with Shad(?), Fiorenza Park, Houston, Texas. This is the first time I’ve seen a cormorant eat a fish other than an armored catfish at Fiorenza. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
Finally, we witnessed some survival of the fittest action in stark, brutal terms at the Smith Oaks Rookery, High Island.
Great Egret nestlings put on a show of pure Id as they attempted to jostle, push, or toss each other from their nests. One nasty little bird had its sibling by the scruff of the neck and attempted to toss it from the nest for a solid fifteen minutes. When it accepted that its nemesis was just as strong and heavy as it was, the aggressor cuddled up for warmth. Charming.
In less than two hours, I witnessed three displaced Great Egret nestlings being eaten by alligators. The Cain and Abel stuff probably tapers off for the night as the warming rays of the sun disappear.
One Stone-cold Killer Eats Another: Alligator with Great Egret Nestling, Smith Oaks Rookery, High Island, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
Sometimes siblings can get in each other’s space. –Gisele Bundchen
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.
Black-necked Stilts 1: The Nod, Lafitte’s Cove, Galveston Island, Texas. The ritual proceeds with a nod to the presenting female. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). High-speed synchronized fill-flash.
He then stirs the water with his beak . . . .
Black-necked Stilts 2: Look what I can do! Lafitte’s Cove, Galveston Island, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
The male strolls to the female’s other side . . . .
Black-necked Stilts 3: The Stroll, Lafitte’s Cove, Galveston Island, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
Here, he again stirs up the water with his beak . . . .
Black-necked Stilts 4: Look what I can do (again)! Lafitte’s Cove, Galveston Island, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). High-speed-synchronized fill-flash.
The male then mounts the female and consummates the relationship . . . .
Black-necked Stilts 5: The Act, Lafitte’s Cove, Galveston Island, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). High-speed synchronized fill-flash.
After copulation, the male descends. He then places his wing over her body and crosses his bill over hers . . . .
Black-necked Stilts 6: Crossed Beaks, Lafitte’s Cove, Galveston Island, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). High-speed synchronized fill-flash.
The pair then promenades together for a few paces. They are now together . . . for at least this breeding season.
Black-necked Stilts 7: Begin Promenade, Lafitte’s Cove, Galveston Island, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4xTC). High-speed synchronized fill-flash.
Swimming Diamondback Water Snake, Fiorenza Park, Houston, Texas. No birds means looking for other subjects. This snake was living dangerously: The water at Fiorenza is filled with fishing cormorants. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). High-speed synchronized fill-flash.
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 . . . .
Dabbling Mottled Drakes, Lafitte’s Cove, Galveston Island, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). No migrant songbirds around? Just photograph some resident ducks! High-speed synchronized fill-flash.
Birds’ love and birds’ song
Flying here and there . . . . Spring, Alfred Lord Tennyson
Female Common Yellowthroat on Dead Vegetation, Pilant Lake, Brazos Bend State Park, Texas. Common Yellowthroats are among the most common warblers in North America. They winter primarily in Mexico and Central America and breed across the United States. They can be found year-round along the Texas Gulf Coast. The south side of Pilant Lake is a great place to see them picking bugs from emergent vegetation (alive or dead). Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
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.
Resident: Young Reddish Egret (White Morph), East Beach, Galveston Island, Texas. This bird was taking killifish from small tidal channels. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
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!
Loggerhead Shrike with Caterpillar, Lafitte’s Cove, Galveston Island, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
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!
Female Wilson’s Plover, East Beach, Galveston Island, Texas. Breeding Wilson’s Plovers begin arriving along the Texas coast in mid-February and depart by September. They nest on simple scrapes on beaches, among other places, from April to June. Note the new growth sprouting up from among dead old-growth. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
Many great actions are committed in small struggles. –Victor Hugo
A Great Egret Shades its Young, Smith Oaks, High Island, Texas. Even in March, the brutal Texas sun can kill delicate nestlings. Mom (or dad) to the rescue! Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
As I write this, we stand on the cusp of the best month of birding on the calendar! But for the past few weeks we’ve been (mostly) photographing our more typical species (year-’rounds, wintering or summering species) going about their business, not transients flying through from somewhere to somewhere else.
Singing Male Red-winged Blackbird on Rice Plant, Pilant Lake, Brazos Bend State Park, Texas. The margins of Pilant Lake were filled with Red-winged Blackbirds (and their calls) on our last visit. What a nice change: The marsh sounds as it should. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
One of the more pleasant surprises of the past few weeks is the recognition that Brazos Bend State Park (BBSP) is starting to rebound a bit from the catastrophic floods of the recent past. It is still nowhere near the mecca for observing wader action that it was before, but day by day things are improving. It will be interesting to see if songbirds return for nesting in a big way. Elisa spotted a female Northern Cardinal building a nest just above water-line on Pilant Slough, and the trilling songs of Northern Parulas are everywhere. Can Prothonotary Warblers be far behind?
The Flip, Fiorenza park, Houston, Texas. The catfish hunt goes on! This juvenile Neotropic Cormorant is attempting to maneuver a spiny armored catfish into swallowing position. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.White Ibis in Breeding with Beak Full of Arthropods, Pilant Slough, Brazos Bend State Park, Texas. This bird has (at least) a spider, a water bug, and a metallic bronze damselfly in its beak at the same time. Water hyacinth is a nasty invasive, but it’s full of nutritious bugs! Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
As noted, wader action at BBSP is still a bit down from the best of times, but the patient observer can still see a few things occasionally. Especially prominent now are the American Bitterns. Bitterns can be seen hunting all over BBSP. On our last visit, we observed one confrontation between two birds on Pilant Slough. Soon calling and confrontations should be common, only to die away by May.
In any case, starting today, we’ll shy away from BBSP for a few weeks and visit Galveston more. Hundreds of millions of songbirds have started streaming across the Gulf of Mexico, and we’re not going to miss it! With luck, we’ll capture some of these birds in action . . . Sipping from a flower, here, or grabbing a dragonfly, there. Can’t wait!
American Bittern with Crawfish, 40-Acre Lake, Brazos Bend State Park, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.Looking American Bittern, 40-Acre Lake, Brazos Bend State Park, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
A light exists in spring
Not present on the year
At any other period.
When March is scarcely here . . . .
—Emily Dickinson, A Light Exists in Spring
Roseate Spoonbill in Flight, Smith Oaks Rookery, High Island, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
In our travels last week, we stopped by Smith Oaks on High Island, Texas, one of the most famous birding sites on the Texas Gulf Coast. Although we saw no early migrant songbirds in the surrounding woods, the rookery was hopping with activity—the drive toward life.
Nest-sitting Neotropic Cormorants, Smith Oaks Rookery, High Island, Texas. Note that the nest is stained white with guano. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
Spoonbills, egrets, and cormorants filled the air. Great Egrets and Neotropic Cormorants shuttled back and forth with nest-building materials. Double-crested Cormorants fished in the water surrounding the rookery. Some Great Egret pairs were building nests, sitting on eggs, or rearing chicks. Neotropic Cormorants were nest-sitting, but no chicks were to be seen. A few energetic Tricolored Herons swooped past but gave no indication of intentions. Spoonbills squabbled with each other: Nesting can’t be far behind!
Snowy Egrets in High Breeding, Smith Oaks Rookery, High Island, Texas. In high breeding color, Snowy Egrets have pink lores and feet. Canon EOS 7DII/600mm f/4 L IS (+1.4x TC). Natural light.Nest-building Great Egrets, Smith Oaks Rookery, High Island, Texas. Nest building is a team effort for Great Egrets. Note the fluorescent green lores of high breeding color. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
Great and Snowy Egrets in glorious breeding plumes (that almost doomed these species to extinction in the Gilded Age) with lores ablaze in electric colors were everywhere and revved up on hormones. Soon, the later-breeding species, Cattle Egrets, Tricolored Herons, and Roseate Spoonbills, will join the frenzy. By that time, the trees will be filled with brilliant flashes of Neotropical migrant songbird plumage and the picture of spring will be complete . . . .
Great Egret Feeding Young, Smith Oaks Rookery, High Island, Texas. A regurgitated crawfish is being presented to the nestlings. Three nestlings are visible in this image, but a fourth smaller one is also present. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
But, as always, predators lurk in the dark water below waiting for larger nestlings to oust smaller, weaker ones, or for birds of any age to simply make a mistake . . . .
Death Stalks the Rookery, Smith Oaks Rookery, High Island, Texas. Despite the beauty, have no illusions: Nature is red in tooth and claw . . . always. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
For life and death are one, even as the river and the sea are one.–Khalil Gibran
What we achieve inwardly will change outer reality. –Plutarch
Common Loon in Pin Feathers, Offatt’s Bayou, Galveston island, Texas. The tips of the pin feathers on the neck and head are pigmented black. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.Common Loon in Pin Feathers 2, Offatt’s Bayou, Galveston Island, Texas. This is the same bird as above. Note the shagginess of the pin feathers on head and neck. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
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.
Common Loon in Transitional Plumage, Offatt’s Bayou, Galveston Island, Texas. This bird appears to be in nonbreeding plumage from the neck forward. Spots on the wings show the transition to breeding colors has begun, though. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.Another Common Loon in Transitional Plumage, Offatt’s Bayou, Galveston Island, Texas. This bird is a little further along than the one immediately above. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
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.
Common Loon in Breeding Colors (Nearly), Offatt’s Bayou, Galveston Island, Texas. This bird was more shy than many others and had apparently already pair-bonded. Another bird in less well-developed transitional plumage kept appearing in close proximity. Could shyness toward humans and pair-bonding behaviors be related? Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
Life is one long process of getting tired.–Samuel Butler
California Pelican, Offatt’s Bayou, Galveston Island, Texas. We always keep an eye out for the red throat pouch—a sign of the Pacific race of the Brown Pelican. The blackish- or brownish-green-throated Atlantic Brown Pelicans greatly outnumber the Pacifics along the Texas Gulf Coast. Canon EOS 7DII/600mm f/4 L IS (+1.4x TC). Natural light.
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
Portrait: Eared Grebe, Offatt’s Bayou, Galveston Island, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
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.
Diving Eared Grebe, Offatt’s Bayou, Galveston Island, Texas. Although grebes have a unique method of foot-propulsion, they look like many other submarine hunters (e.g., loons, mergansers, cormorants) from above the water as they dive after prey. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
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 . . . .
Diving Eared Grebe 2, Offatt’s Bayou, Galveston Island, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
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. . . .
Diving Eared Grebe 3, Offatt’s Bayou, Galveston Island, Texas. Offatt’s Bayou is a great place to see Eared Grebes hunting in winter. Texas City Dike is another. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
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!
Juvenile Pied-billed Grebe with Crawfish, Elm Lake, Brazos Bend State Park, Texas. In the past, Brazos Bend SP was great place to see Pied-billed Grebes hunting year-round. Recent flooding has decimated the ecology of the park, and water birds are no longer abundant. Canon EOS 7D/500mm f/4L IS (+1.4x TC). Natural light.
Reference
Johansson, L.C., and Norberg, U. M. L. Norberg. 2001. Lift-based Paddling in Diving Grebe. The Journal of Experimental Biology204: 1687-1696.
