Galveston Island

Dunlin!

Isn’t life a series of images that change as they repeat themselves? –Andy Warhol

Dunlin in Breeding Color, Lake Superior, Wisconsin
Dunlin (Breeding), South Shore, Lake Superior, Wisconsin. The bright rufous back is unique for a North American sandpiper. Note how trim this bird is compared to the Texas fatties below! Flying a few thousand miles will definitely get a bird in shape! This bird was still on its way to the Arctic. Photo taken in June, 2013. Canon EOS 7D/500mm f/4L IS (+1.4x TC). Natural light.

I continue to find bird watching a most challenging hobby. This week, after reading an article about cormorant identification, I discovered to my horror that I had misidentified several birds in previous posts. I was going by a common field mark (no yellow lores on Neotropic Cormorants), published in many field guides—that is wrong! As a result, I went through the entire blog and made corrections.

Small sandpipers, too, are the stuff of nightmares, as far as bird identifications go. For some reason, I often find myself staring at Dunlins, trying to establish a gestalt to distinguish them from the other look-alike cutie-pie sandpipers they might be . . . .

Dunlin, East Beach, Galveston Island, Texas
Dunlin (transitional), East Beach, Galveston Island, Texas. Photo taken this spring. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.

Because Dunlins breed in the Arctic and winter along the Texas Gulf Coast, we usually don’t see them in their distinctive breeding colors. This spring I’ve seen a few transitioning into breeding plumage, though. And in those cases, it really helped with the identification—especially the black belly feathers coming in, which are unique for a Texas sandpiper. Otherwise, I’m looking for black legs and a long, droopy black beak on a butterball. If you see these features, you’ve only got to make sure you haven’t got a Western Sandpiper, and you’re done—except for figuring out what the bird’s up to!

Dunlin, Frenchtown Road, Bolivar Peninsula, Texas
Dunlin (Nonbreeding), Frenchtown Road, Bolivar Peninsula, Texas. Photo taken November 7, 2016. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.

©2017 Christopher R. Cunningham. All rights reserved. No text or images may be duplicated or distributed without permission,

Spring at the Shore

Hug the shore; let others try the deep. –Virgil

Portrait: Whimbrel, Frenchtown Road, Bolivar Peninsula, Texas
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.

Long-billed Dowitcher, Lafitte's Cove, Galveston Island, Texas
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, Bovlivar Peninsula, Texas
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
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.

©2017 Christopher R. Cunningham. All rights reserved. No text or images may be duplicated or distributed without permission.

Songbirds Among the Vines

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 Grape Vine, Lafitte's Cove, Galveston Island, Texas
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 . . . .

Grape Leaffolder Caterpillar (Desmia funeralis), Lafitte's Cove, Galveston Island, Texas
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.

Palm Warbler, Lafitte's Cove, Galveston Island, Texas
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, Lafitte's Cove, Galveston Island, Texas
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.

Male Summer Tanager, Lafitte's Cove, Galveston Island, Texas
Quizzical Male Summer Tanager, Lafitte’s Cove, Galveston Island, Texas. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.

©2017 Christopher R. Cunningham. All rights reserved. No text or images may be duplicated or distributed without permission.

New Predator-prey Action

Red-eyed Vireo with Dragonfly Caught in Spiderweb, Lafitte's Cove, Galveston Island, Texas
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
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.

Cormorant with shrimp, Fiorenza Park, Houston, Texas
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.
Cormorant with Minnow, Fiorenza Park, Houston, Texas
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.

Alligator with Great Egret Nestling, Smith Oaks Rookery, High Island, Texas
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

©2017 Christopher R. Cunningham. All rights reserved. No text or image may be duplicated or distributed without permission.

The Black-necked Stilt Courtship Ritual

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 Stilt 1, Lafitte's Cove, Galveston Island, Texas
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, Lafitte's Cove, Galveston Island, Texas
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, Lafitte's Cove, Galveston Island, Texas
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 Stilt 4, Lafitte's Cove, Galveston Island, Texas
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 Stilt 5, Lafitte's Cove, Galveston Island, Texas
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, Lafitte's Cove, Galveston Island, Texas
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, Lafitte's Cove, Galveston Island, Texas
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.

©2017 Christopher R. Cunningham. All rights reserved. No text or images may be duplicated or distributed without permission.

Still Waiting to See Neotropical Migrant Songbirds . . . .

Nothing happens. Nobody comes, nobody goes. It’s awful.—Samuel Beckett, Waiting for Godot

Swimming diamondback water snake, Fiorenza Park, Houston, Texas
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
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.

©2017 Christopher R. Cunningham. All rights reserved. No text or images may be duplicated or distributed without permission.

Spring: The Old and New

Birds’ love and birds’ song
Flying here and there . . . . Spring, Alfred Lord Tennyson

Common Yellowthroat, Pilant Lake, BBSP, Texas
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.

Portrait young Reddish Egret, East Beach, Galveston Island, Texas
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 wiht Caterpillar, Lafitte's Cove, Galveston Island, Texas
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!

Wilson's Plover, East Beach, Galveston Island, Texas
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.

©2017 Christopher R. Cunningham. All rights reserved. No text or images may be duplicated or distributed without permission.

Common Loons: Into Breeding Plumage

What we achieve inwardly will change outer reality. –Plutarch

Common Loon in Pin Feathers, Offatt's Bayou, Galveston island, Texas
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, Offatt's Bayou, Galveston Island, Texas
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, Offatt's Bayou, Galveston Island, Texas
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.
Common Loon, Offatt's Bayou, Galveston Island, Texas
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 (Nearly) Breeding Colors, Offatt's Bayou, Galveston Island, Texas
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.

©2017 Christopher R. Cunningham. All rights reserved. No text or images may be duplicated or distributed without permission.

The Two Shutterbirds Take a Break!

Life is one long process of getting tired.–Samuel Butler

California Pelican, Offatt's Bayou, Galveston Island, Texas
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!

©2017 Christopher R. Cunningham and Elisa D. Lewis. All rights reserved. No text or images may be duplicated or distributed without permission.

Grebes: Unique Foot-propelled Divers

Feet, what do I need you for when I have wings to fly?—Frida Kahlo

Eared Grebe, Offatt's Bayou, Galveston Island, Texas
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
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, Offatt's Bayou, Galveston Island, Texas
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, Offatt's Bayou, Galveston Island, Texas
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!

Pied-billed Grebe withCrawfish, Elm Lake, Brazos Bend State Park, Texas
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 Biology 204: 1687-1696.

©2017 Christopher R. Cunningham. All rights reserved. No text or images may be duplicated or distributed without permission.

 

Birds in “Good” and “Bad” Light

There is nothing either good or bad but thinking makes it so. –William Shakespeare

Double-crested Cormorant with Plecostomus, Fiorenza Park, Houston
Double-crested Cormorant with “Plecostomus,” Fiorenza Park, Houston, Texas. We Texans may be horrified by the proliferation of these South American armored catfish in our waters, but to cormorants that range far to the south, it still feels like home when they’re around. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.

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.

Neotropic Cormorant with Plecostomus, Fiorenza Park, Houston, Texas
Eye to Eye: Neotropic Cormorant with “Plecostomus,” Fiorenza Park, Houston, Texas. In this shot, the sun was in the wrong position (or rather I was), leading to too much glare from the water and a backlit bird. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.

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!

Eared Grebe, Offatt's Bayou, Galveston Island, Texas
Ad Noctem: An Eared Grebe Paddles off into the Fog, Offatt’s Bayou, Galveston Island, Texas. I like the way the wake ends at a veil of fog. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
Eared Grebe, Offatt's Bayou, Galveston Island, Texas
Eared Grebe, Offatt’s Bayou, Galveston Island, Texas. Perfect light, but not perfect perspective. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.

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!

Common Loon, Offatt's Bayou, Galveston Island, Texas
Made in the Shade: Common Loon, Offatt’s Bayou, Galveston Island, Texas. It looks like this bird is swimming in mercury. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.
Common Loon, Offatt's Bayou, Galveston Island, Texas
Transitional Common Loon, Offatt’s Bayou, Galveston Island, Texas. Images from this locale tend to look better from a bit of a distance, given the raised nature of the observation platform. Canon EOS 7DII/600mm f/4L IS (+1.4x TC). Natural light.

©2017 Christopher R. Cunningham. All rights reserved. No text or images may be duplicated or distributed without permission.

Cooperative Feeding in American White Pelicans

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

Line of American White Pelicans, East Beach, Galveston Island, Texas
Line of American White Pelicans, East Beach, Galveston Island, Texas. Canon EOS 7D/600mm f/4L IS (+1.4x TC). Natural light.

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 Pelican Feeding Frenzy, East Beach, Galveston Island, Texas
American White Pelican Feeding Frenzy, East Beach, Galveston Island, Texas. Canon EOS 7D/600mm f/4L IS (+1.4x TC). Natural light.

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).

Pelican Phalanx, East Beach, Galveston Island, Texas
Pelican Phalanx, East Beach, Galveston Island, Texas. Canon EOS 7D/600mm f/4L IS (+1.4x TC). Natural light.

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.

After fishing, East Beach, Galveston Island, Texas
Back in Line, East Beach, Galveston Island, Texas. Canon EOS 7D/600mm f/4L IS (+1.4x TC). Natural light.

©2017 Christopher R. Cunningham. All rights reserved. No text or images may be duplicated or distributed without permission.