The Nature Writers of Texas

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

Sunday, November 30, 2003

Book Review
The Behavior of Texas Birds
Ro Wauer, November 2003, The Victoria Advocate, © 2004

This book - The Behavior of Texas Birds - is the first of its kind. It is a superb book! Anyone interested in birds, whether they are avid birders or only watch yard birds, will want to own this one. Written by Kent Rylander, Professor of Biological Sciences at Texas Tech University, this book will serve as an excellent resource for all of us that want to know more about bird behavior, beyond the basics included in field guides. It is very obvious that the author has acquired years of good data, and he has been able to compile that information into an easily usable reference.

Rylander begins by explaining the principals of animal behavior and illustrating how they can be applied to interpreting bird behavior in the field. Then he goes about discussing the behavior of more than 400 of our Texas birds. Each species account describes such behaviors as feeding, courtship, parenting, and other behaviors that are significant for that species. He also incorporates significant references, all of which are listed after the species accounts by bird groups.

To illustrate how useful this book is for my readers, here are a few examples. He points out that grebes feed principally on fish, but they also consume lots of feathers. They even "feed feathers to their young. It was formerly thought that feathers protect the intestinal walls from being injured by fish bones, but more likely grebes ingest feathers as a way of recycling oils and other nutrients." For wood ducks, Rylander explains that they walk erect on can even run on the forest floor "where they consume more acorns than any other waterfowl." He also explains why ducks possess a more complex courtship display than most birds: ducks usually select a new mate each year, and one way she is able to select a mate of her own species is not by the drake's appearance as much as by its unique courtship display.

Three raptor characteristics seemed fascinating: Bald eagles seem to play a good deal. "For example, several birds spiral high into the air while following a bird that is carrying a stick. When the bird drops the stick, another bird catches the stick before it reaches the ground, and then this bird flies up and drops the stick." Red-tailed hawk eyesight is remarkable, "capable of focusing on potential prey at 500 feet or more." And the mate selection of American kestrels is determined by the female that copulates with several males: "This behavior is sometimes explained by the mate assessment hypothesis, which maintains that birds assess the genetic potential of other birds by frequently copulating with them."

Did you know that our common Inca dove roosts in pyramids during cold weather? Rylander wrote: "Frequently, 50 or more birds flock together in winter. In cold weather a dozen or more perch on each others' backs to form a pyramid two or three tiers deep. They remain like this for about an hour during the day, evidently to maintain body warmth." And our little Eastern screech-owl brings live worm snakes to its nest. "These small, wormlike snakes are released in the nest's debris, where they burrow out of sight and eat insects and mites. Owlets in nests with these snakes grow faster - and have a lower mortality - than those raised without snakes."

The Behavior of Texas Birds is filled with such fascinating information. Rylander mentions that a pair of scissor-tailed flycatchers placed their nest on a working oil pump and "successfully raised their young in spite of the incessant up and down movements." And did you know that female cardinal (redbirds) "with brighter underwing plumage spend more time feeding their offspring than those having duller underwing plumage. This relationship supports the good-parent hypothesis, which proposes that color brightness signals to a potential mate how well she will care for her offspring."

This is an amazing book, filled with lots of fascinating tidbits. Published by the University of Texas Press, it sells for $26.95 paperback, or $60.00 library edition. In the Texas Coastal Bend, it can be purchased at Tricia's Antiques and Gifts, 117 John Stockbauer, in Victoria.

Chipping Sparrows are one of our
Smallest Winter Visitors
Ro Wauer, November 30, 2003, The Victoria Advocate, © 2003

This little winter sparrow has already become a fixture in my yard, consuming an unbelievable amount of seeds for such a tiny bird. On returning home from a week in Utah, visiting my 82-year old mother, it was the very first bird found at my feeders; it had not yet appeared before my trip. Its appearance is one more reliable sign that winter is really with us.

Chipping sparrows are tiny birds, especially in comparison with most of the other feeder birds, such as cardinals, Inca doves, house sparrow, and such. Yet, at least adults, are one of our most distinct species, readily identified by their small size, red cap, gray collar, and black line that runs from the top of the bill back to the nape. Young birds can be confusing, however, as they are very nondescript with fine streaks on their breast and somewhat heavier streaks on their back. But youngsters and the adults usually occur in small to large flocks, and usually feed together at feeders. They prefer to feed on the ground, but will also take advantage of whatever small seeds are available at feeders at any height.

Although chippers do not nest in South Texas, they do nest in the Texas Pineywoods and a portion of the Hill Country, as well as in the Davis and Guadalupe Mountains of West Texas. On the breeding grounds they are very vocal, singing a trilling songs throughout the daytime. On their wintering grounds, including South Texas, they rarely sing early on, but by early spring they begin to utter partial songs. And just before they depart they can often be heard singing almost full songs. Many of the partial songs apparently are practicing juveniles.

Chipping sparrows are most closely related to Brewer's, clay-colored, and field sparrows, also little birds that occasionally spend their winters in South Texas. Field sparrows, in particular, can be expected in weedy areas most winters. It looks very different with a pinkish bill, gray collar, and white eye ring; it does not possess the black line that runs from the bill to the nape of the chipping sparrow. Field sparrows also nest in Texas, including most of the Hill Country, where their sing very distinct descending trills that sound like someone holding a paddle over a ping pong ball.

Chipping sparrows will be with us throughout the winter months, but begin to move northward by March. Some remain until mid-May; probably those individuals that can depend upon a steady food supply at feeders. While they are with us, they can be fun to watch, as they are one of the most aggressive of all of sparrows. Maybe because they are so small, like hummingbirds, they seem to spend an amazing amount of time bickering with neighbors. They will even charge another chipping sparrows if it gets in the way or agitates it for some reason. They are real characters and worth watching.

Sunday, November 23, 2003

The Turkey is our Symbol of Thanksgiving
Ro Wauer, November 23, 2003, The Victoria Advocate, © 2003

The turkey, that huge, ungainly bird of the oak woodlands and barnyards, has become a common symbol of Thanksgiving. No "Turkey Day" would be complete without it.

We are told that turkey is one of the most nutritious and healthy foods; we are encouraged to eat it year-round. For me, however, except for that marvelous smell from the oven, freshly cooked turkey is rarely as appealing as it is two or more days later. I like it best when I can pick the remaining meat from the bones or eat it in a sandwich or in enchiladas.

The vast majority of the frozen turkeys we purchase at the grocery stores are mass-produced and are a far cry from the critters that occur in the wild. Harry Oberholser, in The Bird Life of Texas, provides a marvelous comparison: "A wild gobbler has an alert eye in a slender blue head, a streamline body covered with highly burnished feathers, and long legs; the domestic bird has a dull eye sunk into a swollen red head, a flabby body clothed in dirty feathers, and dumpy legs. The former bird runs better than a race horse through the woods and flies as lightly as a ruffed grouse; the latter can scarily walk about its pen, much less fly." Wild turkeys can be separated from feral turkeys by the tuftlike beard hanging from the wild male (occasionally female) bird's chest.

Wild turkeys are magnificent birds, especially a courting male that struts about in a pompous manner with a fanlike tail display and expressive gobbling. The polygamous gobbler maintains a sizable harem, fending off rival males. The hen hides her nest with great care and protects it and a dozen or so eggs against predators and other invaders. Incubation takes about twenty-eight days, but the poults are so precocial that the hen and young leave the nest immediately after the last egg has hatched. Within three weeks, they are able to fly well enough to perch overnight in trees. By fall, when acorns are ripe, several families may congregate into huge feeding flocks.

The Native Americans had already domesticated wild turkeys by the time the first Europeans reached North America, and it was one of the very few animal imports to the Old World. The abundant wild turkeys of the New World (estimated at 10 million) became all important to the settlers. They were so important, in fact, that when our "national bird" was chosen, the turkey was second only to the bald eagle. Benjamin Franklin defended the turkey as his choice because it was "more respectable" than the "thieving, scavenging bald eagle."

As Europeans moved westward, wild turkeys were plentiful throughout the eastern half of the continent, but by the late 1800s, only remnants of the original populations remained. So, today, the Texas turkey population is largely a product of reintroductions from other localities. But because of its adaptable nature, it has become commonplace again in our fields and woods. No other creature is so representative of our natural world, as we prepare to give thanks for our many blessings, as our wild turkey.

Sunday, November 16, 2003

A Favorite Wintering Yard Bird
Ro Wauer, November 16, 2003, The Victoria Advocate, © 2003

Everyone probably has a favorite wintertime yardbird, one that spends its winter months in your yard. These can be winter-only species, such as the eastern phoebe, ruby-crowned kinglet, or yellow-rumped warbler, or full-time residents, such as the Carolina chickadee, Carolina wren, or northern cardinal.

Those who pay attention to their wintertime yardbirds may already have a favorite, but I honestly don't. If forced to make a decision, I would have a difficult time of it. But I'll try, nonetheless. Maybe I will first select a top five or six species. That might include the buff-bellied hummingbird, yellow-bellied sapsucker, eastern phoebe, Carolina chickadee, Carolina wren, orange-crowned and yellow-rumped warblers, and Lincoln's and white-throated sparrows. Opps, that's nine species instead of five to six. Oh well, but how to pick just one?

Buff-bellied hummingbirds could well be a favorite. A year-round colorful resident that readily comes to feeders for great views, and a personality that is one of a kind. And it is a tropical species at the northern edge of its range, kind of special in anyone's perspective. But the yellow-bellied sapsucker is also special. It is a keystone species that keeps sap wells open all winter that attract and help feed other birds and insects. Pretty special indeed. Besides, these woodpeckers may have come a long way from their northern breeding grounds to overwinter in my yard.

The eastern phoebe has not traveled so far, since some nest in the northern half of Texas. This flycatcher does just fine even during cold weather when insects are few and far between; it is an extremely adaptable species. It gets high marks for its persistence, in addition to its usual abundance in winter. And who can slight the Carolina wren? For no other reason that it has entertained me all the rest of the year. No other songbird builds its nests in my flowerpots.

Warblers are always special, especially those that winter north of the Mexican border; most of their relatives seek more tropical habitats with easier pickings. Orange-crowns are tough little birds; fellow birder Mark Elwonger and I once watched one individual kill another one trying to take over a feeder during a freezing rain in the Lower Rio Grande Valley. Besides, orange-crowned warblers breed in some of my favorite habitats, spring sites in the highlands of the Rocky Mountains. Yellow-rumps also are breeding birds of the northern highlands and all of northern North America, and they are one of the few warblers wintering in numbers in the United States. This little yellow-rumped bird even sings partial songs in my yard on sunny winter mornings.

Then there are the two sparrows mentioned above, Lincoln's and white-throated. Lincoln's sparrows are skulkers that are never very obvious, but they stay close to sheltered areas along the edge of my yard. They only occasionally come to my seed feeders; really gutsy for such a small bird. They also possess a subtle beauty in the own right, buff breast and a contrasting facial pattern. White-throated sparrows are also colorful, with the adult's snow-white throat and black-and-white crown with a golden spot in front of each eye. In addition, anyone who has spent time if the northern forests, cannot help but have a special appreciation for its' marvelous song - "pure sweet Canada Canada" or "sow wheat peverly, peverly, peverly, peverly" - that can often be heard in sunny winter days.

Which one is my most favorite? What a decision! But I forgot two other favorites, American kestrel and American robin. - Maybe I had better leave such a major decision up in the air. After all, cedar waxwings, Carolina chickadees, chipping sparrows, and American goldfinches are pretty special wintering yardbirds, too.

Sunday, November 09, 2003

Changing Leaf Color even in South Texas
Ro Wauer, November 9, 2003, The Victoria Advocate, © 2003

Almost everyone admires the beautiful mountainsides and hills of the Western and Eastern states in fall. That is when the leaf colors change from greens to red, browns, and yellows. Golden-colored aspens in the Rocky Mountains can be so spectacular that they become a long-lasting memory. And the changing colors of the eastern maples, oaks, and other broad-leaf trees can beckon us back time and time again. But, even those of us that live in South Texas can get a tiny taste of color from a few of our broad-leafs, representing a change in season that is rather subtle.

Chemistry is most responsible for the color changes. Tree expert Robert Bartlett explained the process this way: "As summer wanes a band of tiny cells at the end of a leaf stem, where it looks like a twig, begin to dry and harden. This stops up the plumbing system inside the leaf. The manufacture of sugar slows down and the green chlorophyll no longer reached the leaves. Now yellow pigments that have been masked within the leaves all summer are revealed. The red pigments are manufactured and the trees take on a kaleidoscope of hues and tones, a harmony of color."

Locally, the nonnative Chinese tallow tree may provide us with considerable color change when its dark green leaves turn to red, yellow, orange, or purple. Color change is also evident in a number of our native species, such as Mexican buckeye, cedar elm, soapberry, sycamore, willows, and a few oaks.

Location and genetics also are significant factors in leaf colors. The southwestern side of a tree usually has a deeper color since it gets more sunshine. Trees in lower places may show color earlier than those in higher spots if cold air settles in the low spots on still nights and the cooler temperatures trap sugar earlier. Generic differences are also important. Typical red leaves are found in maples, dogwoods, and red and scarlet oaks. Browns and oranges are typical for white and black oaks, hickory, and hornbeam, while yellows are more prominent in cottonwoods, pecans, redbud, and elm trees.

Some eastern Native American tribes claimed that leaf changes were due to celestial hunters who killed the Great Bear and that his dripping blood fell onto the forest trees, gradually changing the leaves to various shades. And although "Jack Frost," or the actual occurrence of frost, has little to do with the changing colors, weather is involved. If the fall is rainy, cloudy, or very hot, the foliage generally becomes bland, yellowish, or less vivid. Sugars, which are manufactured by the leaves, are transported down into the trees where they have little effect on fall foliage.

Even though our fall colors are less dramatic than they are to the north, they still represent a change in season, a time to appreciate the end of hot weather and the beginning of mild winter days.

Sunday, November 02, 2003

Harris's Hawks are Something Special
Ro Wauer, November 2, 2003, The Victoria Advocate, © 2003

On a recent trip to the Rio Grande Valley, I was once again impressed with the numerous Harris's hawks found along the way. Although these marvelous raptors can often be found as far north as Victoria and Jackson counties, they are far more numerous to the south. And they often are seen on utility poles along the main highways. Sometimes they will allow a good close view. Then their contrasting plumage of a black-brown back, front, and head, chestnut shoulders and feathered legs, and a white tail marked with a broad black band, can be admired. Slightly smaller than our red-tailed hawk, they are one of our most colorful and fascinating raptors.

Its flight is sometimes slow and sluggish, and usually fairly low over the ground. But they also can soar high overhead, especially when the thermals are good, and may even soar out of sight from the ground. Vocalizations are usually rather weak "eee eee eee eee," but they also possess a loud harsh "karr" call.

Harris's hawks, most closely related to the common black-hawk of the Southwest, ranges from coastal Texas west through most of southern Arizona. They are found among the saguaros of Arizona's Sonoran Desert and within the Big Bend Country of Texas, but they are most abundant in South Texas. They prefer semiarid woodlands and brushlands. Prey species include a variety of creatures that utilize these habitats, including various rodents and snakes, lizards, cottontails, and even insects on occasions. Wood rats and mice are favorite prey.

Harris's hawks are highly social birds, usually found in family groups and known to hunt cooperatively. Ornithologist James Bednartz reported on "social foraging" as a common technique for this species. Groups of four and five Harris's hawks often pursue prey as a relay team. He found this hunting method produced higher success than when hunting alone or in pairs. And ornithologist William Mader found that Harris's hawk nest not only in pairs (twosomes) but also in trios (threesomes). He reported that the "extra hawk served as a nest helper by feeding the chicks and/or supplying prey at the nest." Although helpers are utilized by a few other bird species, such as bushtits, Harris's hawk helpers are unique in the raptor world.

Of course, all of the raptors are rather unique, each one in its own right. Another hawk I am rather partial to is the white-tailed hawk, a South Texas specialty, and often considered the most beautiful of all our raptors. But even the stately red-tailed hawk is special. And who could complain about our bald eagle that is resident in our area all winter into spring. Our full-time resident red-shouldered hawk is also special, although it is often ignored because it is so common. Another rather special wintertime hawk is the northern harrier, the white-rumped, long-winged raptor that cruises low over our fields and pastures. And who does not appreciate the peregrine falcon in winter? This large falcon is the fastest bird in the world, able to dive at more than 100 miles per hour. Although it is most often found along the coast, it occasionally is found inland.

South Texas has more wintertime raptors than anywhere else in North America, as many as 17 hawks and 6 owls. Each take their share of rodents and other creatures often considered vermin by some folks. But all of the birds and their prey are part of an amazing web of life, one that we all have responsibilities to protect.