Sunday, May 3, 2015

Turkey Vulture

While we were near Dallas, we visited Lewisville Lake. A couple of Turkey Vultures fed on the shore. I thought one had an extraordinary collar, but it was not until I worked on the photo that I realized this was actually a radio transmitter. Notice the arial running down the vulture’s back.

A quick and cursory Internet search resulted in finding a vulture-radio-tagging program by the Hawk Mountain Sanctuary. I have no guarantee that this vulture is one of theirs. But, nevertheless, two still-living vultures banded in Saskatchewan, Canada, migrated over the Dallas area on their way to southern Central America and Venezuela. Both migrations skirted the Gulf of Mexico, and cruised along the Mexican coast through eastern Texas. Perhaps this bird is a Canadian returning home.

Saturday, May 2, 2015

Broad-winged Hawk

John Holden and I discovered this small hawk in Rice County last Wednesday. The bird is perched on one leg. The odd-looking, yellow projection sticking out of the hawk’s belly is part of the bird’s right leg. I don’t think the leg is broken. Rather what you see is one of the toes, with the claw either missing or folded back in under the belly feathers.  Hawks and other birds often perch on one foot. See, for example, a photo of a Red-tailed Hawk that I posted in 2011. I am planning a future post on this behavior in the near future.

Broad-winged Hawks are common, albeit secretive, breeders across southeastern Canada and most of the eastern United States. They are, however, often abundant during migration, when flocks of hundreds can be seen as they make their way north in the spring or south in the fall. They winter from southern Mexico south into northern South America, even as far as Peru and Bolivia. Curiously a few also winter in southern-most Florida.

Friday, May 1, 2015

Brown-headed Cowbird

Brown-headed Cowbirds are brood parasites—they lay their eggs in other birds’ nests. At one time, cowbirds were only found in short-grass prairies. They followed buffalo and ate insects kicked up by the mammals.

With Western conquest of North America, forests were felled and forest and prairie were converted to farming and suburbia. Cowbirds moved into these areas, where they parasitized new species unadapted to coping with cowbird eggs in their nests. Many of these new host populations have declined as a result. Cowbirds can lay up to 40 eggs in a single season (Lowther 1993).

Erika and I photographed this male cowbird in a Dallas, Texas, suburb during our travels last March.

Thursday, April 30, 2015

Speckled Green Fruitworm Moth

Scott King told me the identity of this moth. Field marks include the large, liver-shaped spots on the back of the wings—spots that have a large black dot on the inner halves. I found this moth, to my surprise, on a fake, floating waterlily in our water-feature. (The water-feature is always too shady and now is too early for waterlilies for the pond to support real waterlilies.)

A wide variety of deciduous trees serve as hosts for Speckled Green Fruitworm Moth caterpillars. These caterpillars are, indeed, green and often damage fruit crops. The genus is usually nocturnal and can be baited with sugar water or light (Peterson (2012). To me, because of its furry body and black eyes, this moth looked like a caped, extra-terrestrial creature from a Star Wars movie. In fact not extra-terrestrial, this species is found throughout eastern North America.

Wednesday, April 29, 2015

Spring Beauty

Every spring, Erika and I find Spring Beauty flowers. Usually they are solitary or in small clusters. This year, however, we were surprised to find them growing in luxuriant mats. I blogged about Spring Beauty in 2011 and 2013.

Spring Beauty's scientific name is Claytonia virginica. The species name, virginica, simply means that the plant is from Virginia. Claytonia has a more interesting derivation. In the early 1700s, John Clayton was a Virginia county clerk whose passion was botany. He sent specimens to Mark Cateby (a naturalist who was also a famous ornithologist) who forwarded many of Clayton’s specimens to European botanists. Among these Europeans was Linnaeus, who, in 1730, using Clayton’s collections, named 400 new plant species, including Spring Beauty (Gracie 2012).

Tuesday, April 28, 2015

Hermit Thrush

I took this photo of one of the Hermit Thrushes I banded this spring to show off some of its field marks. A little creative Photoshopping erased my hand. Two things to consider first. The Hermit Thrush is the only thrush expected in the Upper Midwest in April—it is an early migrant, usually seen before the other thrushes arrive. Next, the Hermit Thrush habitually bobs its tail up and down.

The distinct spots on the breast might tempt you to call this a Wood Thrush. But Wood Thrushes are larger birds that have reddish heads, brighter than their backs and tails. The Hermit thrush only has a reddish tail. Veerys are uniformly reddish above. Finally some observers might say this is a Swainson’s Thrush, because of the tan eye-ring. Swainson’s Thrushes do have a tan eye-ring, but lack any rufous color anywhere on their head, back, or tail.

Sunday, April 26, 2015

Double-crested Cormorant

When I took this photo near Dallas, Texas, this spring, I was not positive as what kind of cormorant this one was. The facial skin is yellow like a Double-crested Cormorant, but its bill seems more the size of a Neotropic Cormorant. The Neotropic, however, should have a more distinct white line behind the bill. Likely this individual is a juvenal Double-crested Cormorant molting into adult plumage, since young cormorants often have smaller bills than do adults. In any case, the yellow face is diagnostic of Double-crested Cormorants.

Saturday, April 25, 2015

Yellow-bellied Sapsucker

I banded this female Yellow-bellied Sapsucker on 22 April. Because the facial markings are rather indistinct, I assume this is a second-year bird molting into its adult plumage. Several crimson feathers in the sapsucker’s otherwise white throat fascinated me. I band but a few sapsuckers a year, and I have never noticed red feathers such as these. Male sapsuckers have red throats, but I do not think this bird is a young male. No red adorned the bird’s nape, so it is unlikely to be a hybrid with a Red-naped Sapsucker of the Rocky Mountains.

My Sibley field guideshows nothing like this plumage. When I looked up sapsuckers in Peter Pyle’s Identification Guide to North American Birds, Part I, I discovered that female Yellow-bellied Sapsuckers molt later than do Red-bellied Sapsucker (although molt should be finished by April). Furthermore, female Yellow-bellieds’ throats, while normally pure white, occasionally contain a few red feathers. Pyle’s book, by the way, is a guide to identifying, aging, and sexing North America's songbirds (and a few others). The book is essential for bird banders, and, despite its lack of color illustrations and dependence on written text, is probably well worth the money for intermediate to advanced birders.

Friday, April 24, 2015

Carolina Wren

Carolina and Bewick’s wrens can be difficult to tell apart. Juvenal and worn adult Carolinas can be quite pale below. Bewick’s tend to be browner, less chestnut above—they are also smaller than Carolinas. Finally, as I mentioned in my last post, Bewick’s Wrens have a relatively longer tail that the bird flips about, almost like a gnatcatcher.

This bird in this photograph is clearly a Carolina Wren. This species is common in the southeastern United States and is found in almost every woodland and even in urban areas. This wren’s call is a loud, distinctive “tea-kettle, tea-kettle, tea-kettle,” and the bird is often heard before it is seen,

Thursday, April 23, 2015

Bewick’s Wren

On one morning’s walk near Dallas, Texas, I heard an unfamiliar bird song. It sounded vaguely like a Song Sparrow with a loud trill. I made bird noises—squeaking and such—and attracted the songster’s attention—a Bewick’s Wren.

My not knowing the Bewick’s Wren’s call may be forgiven, as the species has mostly disappeared from the eastern United States. Now they are a bird of the West (see my 2012 post). One field mark worth noting is this wren’s tail, much longer than the somewhat similar Carolina Wren. This particular wren, however, was too shy to let me photograph its tail.

Bewick’s calls vary greatly across their range. Males learn their songs from neighboring birds and they tend to have large repertoires (Kennedy and White 2013). These repertoires gradually change geographically. Here is a link to several Bewick’s Wren songs.