The Nature Writers of Texas

The best nature writing from the newspaper, magazine, blog and book authors of the Lone Star State . . .

Thursday, February 26, 2009

Purple vs. House Finches
by Ro Wauer

A February 10 article in the Victoria Advocate, titled “Birds Shifting North,” with a subtitle “Global warming cited for changes in migration routes,” contained a couple issues that need to be clarified. Firstly, the National Audubon Society study that was mentioned did not suggest that birds are changing their migration routes, but only that several species are beginning to spend their winter months further north than they had in earlier years. Secondly, and totally different, I could not help but wonder how many folks, after seeing the photo of a purple finch, might misidentify our local house finches. Although purple finches do rarely winter in South Texas, the closely related house finch is far more numerous.

The article pointed out that global warming was the cause of many birds shifting their wintering grounds further north. The authors pointed out that the average January temperature in the U.S. has increased from 27 degrees in 1966 to 34 degrees in 2005. The northward shift is indeed a fact, and I suspect that many of our wintering birds that we did not see a few years ago but are now found regularly are the result on climate change. According to the article, the poster bird for this shift is the purple finch that now “winters more than 400 miles farther north than it used to.”

The central reason for this nature note is to discuss the differences between the two finches, so that purple finches will not be reported for what are actually house finches. The two species are not that different, so they could be confused. The females, in particular, are very similar, as both possess streaked underparts. However, the head pattern of female purple finches possesses a broad line through the eye edged with broad whitish bands. Female house finches lack the bicolor head pattern and they are not as bulky as their cousins. Males also have similarities, in that they both possess reddish heads and streaked backs. The head, throat, and back colors of adult male purple finches is more a burgundy-red, while the head and throat of house finches is more a true red color. Plus, male house finches possess a streaked belly and flanks; that of the purple finch is spotty.

There also is a third finch, the Cassin’s finch, that has a number of similarities, but it is found only in the West. In Texas, Cassin’s finches are found only in winter and only in the mountainous areas of the Trans-Pecos. While wintering purple finches are now rare in South Texas, house finches, a species that has a western affinity, has increased in our area in recent years. And they also are increasing in the eastern United States. While it was a rarity when we lived in Washington, D.C. during the 1980s, it is now commonplace there.

All three of these finches are closely related, classified in the same genus, Carpodacus. And they belong in the family Fringillidae that includes goldfinches, siskins, crossbills, and redpolls. The majority of these are of northern affinity. The only two of that breed in South Texas are the house finch (its scientific name is Carpodacus mexicana) and the lesser goldfinch (Carduelis psaltria) that is only an occasional visitor to Victoria County but more common to the south and southwest.

Thursday, February 19, 2009

Clay-colored Robin is a Rare Visitor
by Ro Wauer

What a surprise to find a clay-colored robin in our yard! It was among a hundred or so American robins that we found drinking from our birdbaths. The American robins had arrived in a huge flock, like that had during the last several weeks. This flock was accompanied by a couple blue jays and four green jays, also like what we had observed in recent weeks. But also included in this flock for the first time was a clay-colored robin. In fact, the clay-colored robin was a brand new bird, representing our yard bird number 182.

Clay-colored robins are quite different from their American robin cousins. They lack the robin-red breast and the white eye-rings of American robins. They are olive-brown color above and tawny-buff (clay-color) below, with a yellow bill and finely streaked white throat. They are the same general size as the American robin.

This clay-colored robin is not the first ever for Victoria County, but it is considered an extremely rare visitor. It is even rare in the Lower Rio Grande Valley, although it is now considered a full-time resident there, and it has been found nesting in Hidalgo and Webb Counties. It actually is a Mexican bird that barely reaches the United States. So the few sightings north of the Valley truly are exceptional. According to Mark Lockwood and Brush Freeman’s “Handbook of Texas Birds” (2004), single records exist “from Huntsville, Walker County, Lake Jackson, Brazoria County, and Victoria.”

South of the border, clay-colored robins can be fairly common at choice locations as far south as Central America. They can occur in a variety of habitats, ranging from semiarid areas, riversides, broadleaf forests to about 8,000 feet elevations, plantations, and even in urban areas. In the Lower Rio Grande Valley, they seem to prefer well-wooded locations along the river. Clay-coloreds are rarely found in open areas, seldom found foraging on lawns like their cousins. They prefer “secluded thickets, where it quietly gathers earthworms, slugs, caterpillars, an occasional lizard, and other animal food; also wild figs, bananas, and other fruit,” according to Harry Oberholser’s “The Bird Life of Texas.”

Is the clay-colored robin one of the birds that seems to be affected by climate change? The answer is a probably yes. According to Timothy Brush, author of “Nesting Birds of a Tropical Frontier – The Lower Rio Grande Valley of Texas,” the species was first recorded in Texas in 1940. The earliest nests were recorded in 1986 and 1988 at Bentsen-Rio Grande State Park. It is now a year-round but rare resident in the Valley, from Laredo to Brownsville. And more northern sightings are on the increase. They are welcome in my yard any time!

Thursday, February 12, 2009

Signs of Spring Are Everywhere
by Ro Wauer

In spite of our very dry winter, signs of spring are all around us. Although the spring wildflower bloom has hardly begun, a few early flowering trees and shrubs have begun. Already my agarito shrubs have starting to produce bright yellow flowers, and yellow-flowering huisache trees have been detected in a number of areas. The early spring wildflowers I have so far detected include ten-petal anemone, false garlic, milk vetch, and yellow wood sorrel. Can paintbrushes, puccoons and bluebonnets be far behind?

There are also are early signs of spring from the birds. Perhaps the earliest bird songs to brighten the days are those of the cardinals, but the Carolina wrens express their pleasure as well, singing louder and more spirited than they had during the winter months. Then, Carolina chickadees and tufted titmice add their songs to the springtime chorus. In open wooded areas, Bewick’s wren songs have become more energetic. The soft, melodic songs of eastern bluebirds can be heard about open fields. And the resident red-shouldered hawks begin their courtship, flying overhead and emitting loud calls, all to impress their mates.

A few purple martins have already been detected, although it probably will be another few weeks before our breeding birds return. Their lovely, melodic chirping will soon be heard from an hour before sunup to throughout the daylight hours. To many folks the martins serve as their most important spring herald. And the many additional neotropical songbirds, such as cliff swallows, yellow-billed cuckoos, and painted buntings will return as the days progress.

At about the same time, a number of our regular wintering birds begin moving out, heading for their ancestral breeding grounds to the north. Skeins of geese, especially snows and white-fronts, form long lines as they pass overhead. The sandhill cranes will also be on the move, leaving the feeding fields during March and April, while the larger whooping cranes will begin their departure in April.

Shorebirds also are beginning to move northward. The earliest migrants are likely to include American golden-plovers and upland sandpipers. Some of their cousins, such as black-bellied plovers, dowitchers, and various sandpipers, that have resided on local mudflats and shorelines, move out even earlier. Many of these marvelous birds breed far to the north on the Arctic tundra.

Perhaps the paramount indicator of spring for many of us is the return of the ruby-throated hummingbirds. Although a few of these tiny birds have remained with us all winter long, keeping company with our resident buff-bellied hummingbird, many more ruby-throats will return by March. They will remain through the summer months, and leave for their wintering grounds in late fall, just before our colder weather sets in.

Springtime is an exciting time of year for everyone who enjoys the natural world around us.

Thursday, February 05, 2009

Woodcock is One Strange Bird
by Ro Wauer

There are many oddities about our American woodcock! Firstly, it is classified in the bird world as a shorebird, but it never spends time along the shore like other shorebirds such as sandpipers, curlews and godwits. Woodcocks prefer brushy or grassy areas, at least during the winter months that they spend in South Texas. Secondly, woodcocks are weird looking with their very plump body and long, heavy bill. And thirdly, woodcock behavior is so very different than most other birds.

Last week I received a call from Marlin Frederick who informed me that he had a woodcock hanging out behind his house. He told me that this woodcock stayed much of its time in the open, only flying into a brushy area when disturbed. He invited me over to see for myself. So sure enough, when I reached his home he was able to show me this plump, long-billed, well-marked bird sitting on the lawn some distance from woody habitat that I would have expected it to have chosen for its daytime resting site. I was able to see very well and obtain a number of photos, something that would normally be unusual to say the least. My several earlier sightings have been of birds sitting in brushy cover so that unobstructed photos would be next to impossible.

I was able to see all the features of Marlin’s woodcock: a large, plump body, long heavy bill, fascinating head pattern, large brown eyes, and distinct plumage that include a rusty, non-barred belly, barred crown, and streaked brown and black back with a series of gray blotches. It stayed perfectly still, allowing me to get within 15 feet or so, before it finally flew with a distinct twittering sound into the brush.

Another reason I was surprised that Marlin’s woodcock was “out in the open” is that this shorebird normally is nocturnal in its behavior, feeding at night and hiding in the daytime. The reason for it’s larger than normal eyes. They feed primarily on earthworms by probing and they may even foot-stamp at times to help locate prey. They daily eat more than their weight in earthworms, although if necessary they will also feed on various other soil invertebrates. Their bill contains sensitive nerves, in which the sense of touch is highly developed; it can detect the movement of worms in the soil and capture them by probing. Their keen ears may also help them locate prey.

It is too bad that woodcocks do not nest in South Texas, although they do so throughout much of the eastern half of the state. One of the earliest of birds to leave their wintering grounds and begin courtship on their breeding grounds, woodcock courtship flights are a thing to behold. They will fly upward in increasing spirals to 200 to 300 feet, uttering musical twittering notes, and then circling, zigzagging downward, still singing, to alight on its starting point. There it may walk about stiff-legged with tail erect and spread and with its bill pointed downward, resting on its chest. Then it may produce loud, rasping and emphatic zeeip notes. Then it is time for a repeat flight.

Nesting occurs in swampy or moist areas along the edge of brushy sites. Pairs may both sit on the nest, usually facing in the opposite direction, to protect their eggs or nestlings, especially during cold weather. Two broods are the norm. Incubation lasts about three weeks, and the young are precocial, able to leave the nest within a few days. While feeding nestlings, it is not unusual that several adults utilize the same feeding grounds. Unusual for such a solitary bird.

Where might one see one of these fascinating birds? Although Marlin’s woodcock’s is spending its daylight hours in the open, they are more often found by walking through wooded areas. Thicker patches of woods are better than the more open areas; finding a roosting woodcock is not easy. But finding and observing a woodcock at any time is well worth the effort.