The Nature Writers of Texas

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

Sunday, October 30, 2005

Spiders are Garden Friendly
by Ro Wauer

It seems that every year at about this time spider webs become a real nuisance. Going out each morning to retrieve the newspaper can become an obstacle course with spider webs hanging from almost every tree, and sometimes between tree branches and adjacent structures. Especially early in the mornings before it is light enough to see well, I can end up with webbing all over my face. And occasionally one of the weavers as well. A face to face encounter can be disturbing to say the least! Some of the webbing is thick and sticky, and it can be difficult to get those sticky strands off skin and clothing.

Garden spiders, sometimes known as yellow and black argiope, are common in fall. These spiders, with a leg-span of two to three inches, often construct giant webs, each with vertical white lacing in the center. The adult spider usually rests head downward in the center, waiting to snare a meal. Flying insects make up the majority of their diet, but garden spiders can feed on almost any small creatures, including those as large as hummingbirds and lizards. Once killed and partially eaten the prey is wrapped in webbing for a later meal.

Although garden spiders are our most obvious species, especially in fall, a search of any South Texas garden will undoubtedly turn up a wide assortment of spiders. Others that are likely include various crab, lynx, wolf, and jumping spiders. All can be garden friendly as they do a great job of keeping garden pests controlled. Spiders are carnivorous and do not feed on plants.

Crab spiders are somewhat crablike in appearance; they even walk sidewise. They range in size from one-half to almost two inches in diameter, and can vary in color from brown to green or yellow. Instead of building a web to snare prey, they lie in wait on flowers or leaves. Lynx spiders follow the same strategy in capturing prey, but can also jump and chase down prey with great speed. Mostly green with brown streaks, to blend in well with the vegetation, lynx spiders capture an untold number of butterflies.

Jumping spiders are small- to medium-sized spiders that are rather stout with short legs. Most are black with a red or white spot of the abdomen. And since these spiders hunt during the daylight hours, they seem to be fairly common. Wolf spiders are also daytime hunters. Sometimes called ground spiders because of their preferred habitat, they can be as large as three inches, with long legs and a stout body. Their gray to brown coloration blends in very well with their surroundings.

Spiders are truly abundant creatures; as many as 5,000 species occur in the United States. Some biologists suggest that there may be as many as 50,000 per acre of land, and that as many as 2.25 million may occur on an acre of undisturbed grasslands. All spiders possess eight legs, while insects have six. Also unlike insects, spiders have no antennae, wings, or compound eyes. But they all spin silk, and all are carnivorous. Female spiders deposit eggs in masses that can include two to 250 per mass. The eggs usually are covered with a silk covering or egg-sac, and the females often stand guard over their eggs until the young have emerged. This process takes from a few days to several weeks. The spiderlings undergo several molts before becoming adults, a cycle that may take from eight months to four years. Most spiders live for only a year, although tarantulas may live for several years in captivity.

Except for brown recluse and black widow spiders, two species that are most likely to be found in sheds and dark corners instead of gardens, most spiders are not dangerous to humans. Although all spiders do possess enough venom to subdue or kill prey, people are rarely bothered. However, some folks can be allergic to spider bites. But for the most part, those spiders we find in our gardens are rarely dangerous, are fascinating, and extremely beneficial.

Sunday, October 23, 2005

American Kestrels are Back for the Winter Months
by Ro Wauer

The last couple cold fronts, as mild as they were, have brought a number of northern birds back into South Texas. One of the most attractive and one of my very favorites is the little falcon, the American kestrel. Anyone driving along the highways in winter can find some of these little raptors perched on utility lines, on various snags and poles, or hovering over open areas searching for prey.

Once known as "sparrow hawk," due to its habit of taking sparrows, its proper name is now American kestrel. It also has been called "killy-killy," after its distinct killy-killy call; "windhover," because of its habit of hovering in the wind; "rusty-crowned falcon," due to its reddish cap; and "gavilan chitero" in Spanish-speaking countries.

The kestrel is not a true hawk, such as the much larger, broad-winged buteos - red-tailed, Swainson's, and white-tailed hawks - but it is a true falcon of the genus Falco, closely related to peregrine, prairie, and Aplomado falcons. Each possesses long pointed wings bent back at the wrist and can reach great flight speeds when necessary. A coursing falcon flies fast and direct, usually without interruption. And all four of the above falcons also possess the typical falcon face pattern of a long, black wedge (sideburns) against otherwise whitish cheeks.

Although the larger falcons prey on species such as ducks and shorebirds, kestrels take much smaller prey, including small rodents, birds, snakes, bats, frogs, lizards, and a variety of insects. Crickets and grasshoppers are favorite food items. In fact, in some parts of their range, they are known as "grasshopper hawks," due to their preference for these insects. Kestrel prey is usually located from a perch or by hovering in midair. Prey capture is undertaken by a swift, direct pounce from above, with talons extended. Usually the prey is taken to a perch to eat immediately, but kestrels also are known to store extra food in a protected niche for several days.

Many folks consider the American kestrel the most appealing of all our raptors. Perhaps this is because of their small size, but it also may relate to their ability to adapt to a variety of environments. They seem to do very well in urban settings, so long as they can find food in a backyard or field. They may even nest in tree cavities close to our homes, usually where there is an abundance of local prey, such as house sparrows. But in the wild, they utilize a variety of nesting sites, ranging from tree cavities or old crow or jay nests, such as those in the Texas Pineywoods, or on isolated cliffs in the Chisos and Guadalupe mountains of West Texas.

Like most raptors, females are somewhat larger than the males, 10 to 12 inches in length and with a wingspan of 22 to 25 inches. The males possess the brightest plumage. One of the most colorful of all raptors, they sport a rufous red back and tail, with a black subterminal band and white tip, bluish wings, pale reddish underparts, and white, black, bluish, and reddish head. They also possess a pair of black eye-spots of their nape, thought to be protective coloration; the watching "eyes" may confuse some predators. Females are similar but not so brightly colored and lack the blue-gray-colored wings.

American kestrels occur throughout the Americas, from Alaska south to Tierra del Fuego, the southern tip of South America, and from California east to the West Indies. Although kestrels are rarely found in South Texas during the breeding season, they are abundant in winter when many individuals congregate here from throughout their breeding grounds. They are our avian equivalent of human "snow-birds."

Wherever they have come from, they are most welcome. American kestrels are a favorite visitor to many of us who enjoy birds and the wonderful avian diversity that is available in South Texas.
Ro Wauer's latest book is "The American Kestrel, Falcon of Many Names." Published by Johnson Books, this 102-page, soft-cover book includes numerous color photos; it sells for $15.00.

Sunday, October 16, 2005

Western Tanager, Yard Number 174
by Ro Wauer

The fall migration is well underway, with thousands of birds en route to their wintering grounds to the south. Only a few of those that pass our way may remain in South Texas, while many, many more continue across the border to Mexico, Central America, or even into northern South America. These neotropical migrants will then overwinter in suitable habitats in tropical forest areas, but will eventually return to the United States in spring. The majority of those that pass through our area of South Texas going south will pass this way again in spring. A few others may never come this way again, as those individuals that apparently got off track from their normal southbound route are more likely to follow a more appropriate route.

Finding one of the "out-of-the-way" migrants is always exciting, and when I discovered a western tanager in my yard on October 4, it represented a new bird for my yard list. Now that is not to say that western tanagers have never before been recorded in our area, but I had never before found one in my yard. According to Mark Elwonger's "Finding Birds on the Central Texas Coast," there are scattered records from mid-August to mid-May. And Bill Farnsworth's list of birds found on Victoria Christmas Bird Counts includes one at least every three or four years.

The western tanager is true neotropical species, probably more at home in the tropics than it is during its brief stay in North America. Like so many of the neotropical songbirds, its diet changes from being dominated by insects on its breeding grounds to fruit in the tropics. Although the tanager family is a huge one, with some 224 species in the New World, only four species - western, scarlet, summer, and hepatic tanagers - occur in the temperate zone of North America. Only one of the four, the summer tanager, nests in our area of Texas, utilizing broadleaf woodlands. The western tanager is a western bird that nests in coniferous forest areas in the mountains from the Davis and Guadalupe mountains in West Texas northward to northern Canada. The hepatic tanager breeds in pinyon-juniper woodlands of Southwestern mountain ranges, including the Chisos, Davis, and Guadalupe mountains of West Texas. The scarlet tanager nests in broadleaf woodlands in the eastern portion of North America and only passes through South Texas in migration.

All of the tanagers are some of our most colorful birds, although there is considerable sexual dimorphism. That is, male plumage is different than that of the female. Male tanagers possess considerable red markings; the scarlet tanager may be the best known with the male's scarlet body and coal black wings. Female tanagers are more subtly marked with yellow or greenish bodies and only slightly darker wings. Our local breeder, the summer tanager, is dull red with blackish streaks on the wings and a yellowish bill. The hepatic tanager is liver-red color with gray cheeks and a black bill. The male western tanager, like the one found in my yard, has only a red head. Its body is yellow and black. The back and wings are black while the underside, rump, and collar are bright yellow. It truly is a gorgeous bird!

Another special quality of the tanagers is the male's marvelous singing ability, noted for length and persistence. The females do not sing. But male tanagers, unlike many of the neotropical songbirds, continue to sing throughout the breeding season. And they also give rather distinct call notes throughout the breeding season and even during the winter. For instance, the summer tanager sings a song much like that of the American robin, and the call notes are a dry rattled "pit-a-tuck" or "pit-a-chuck." That call helps one locate one of these wintertime loners.

Sunday, October 09, 2005

Monarch Migration is Underway
by Ro Wauer

Monarch butterfly fall migration is well underway. These marvelous creatures are heading south toward their wintering grounds in the forested highlands of central Mexico. I am daily finding several individuals in my yard, nectaring on various flowering plants or soaring overhead, constantly moving toward their goal another 850-plus miles away. Some of these same individuals may have started their southward trek as far away as Canada, although others may have emerged from a chrysalis much closer, some even perhaps in North Texas. But all are heading south in what is one of nature’s most amazing happenings!

Monarch migration occurs throughout Texas, but the majority passes through the state in two principal flyways. The central Texas route stretches for about 200 miles from Wichita Falls to Eagle Pass, and a second flyway exists along the Gulf Coast. The southbound migrants pass through Texas during September and October, but by the third week of October they have almost all passed through into Mexico. Although Texas migrants may originate throughout much of northern and eastern North America, their journeys end in a ten-acre area in central Mexico where five to six million monarchs over winter together, hanging from conifer boughs in huge clusters.

Monarchs are the only true butterfly migrant, the only species that travels both south and north. Although several other butterfly species, such as the painted and American ladies, red admiral, and several of the large sulphurs, are often considered fall migrants, they rarely live long enough to head back north in spring. They one-way movement is properly called emigration. Monarchs that migrate to Mexico and return to the southern United States live at least eight months, although the spring and summer generations live only four to six weeks. Those that return to Texas in spring, usually in March and April, reproduce as soon as possible and the next generation continues the northward movement. Monarchs breed four to five times per year, and almost every generation is part of the migratory movement.

Monarchs are the poster-child of the insect world. As the best known North American butterfly, monarchs attract an amazing amount on interest throughout the United States. And in spring and fall, when they are in the process of migrating, "Monarch Watch" reporters keep track of their progress and post it on the internet. "Real-time Migration Maps" can be seen at http://www.learner.org/jnorth/monarch/index.html. These are updated weekly. Anyone interested in submitting reports can do so; instructions are available at: http://www.learner.org/egi-bin/jnorth/jn-sightings. And Jim Lovett of Monarch Watch (http://www.MonarchWatch.org) reports that, in spite of earlier predictions of severely declining populations, the fall 2005 migration looks promising.

Monarch migration truly is amazing! Although we are familiar with bird migration, especially those that fly northward from southern Mexico or further south to nest in the United States. But birds are warm-blooded vertebrates, while monarchs are cold-blooded invertebrates, very different creatures, biologically and physiologically. Their survival itself is miraculous! An adult female monarch must find a milkweed plant on which to lay eggs, the eggs must survive long enough to hatch, the tiny caterpillar (a true eating machine) must then pass through four growing stages (instars) before it crawls to a suitable location and “hardens” into a chrysalis, and then the chrysalis must survive several more days before an adult butterfly emerges. All the while, each stage – adult, egg, caterpillar, chrysalis, emerging adult - is subject to cold, heat, aridity, and numerous predators and parasites.

Monarchs, an insect that appears extremely fragile with delicate wings, each fall guides itself thousands of miles over terrain it has never seen before to an isolated site in the high mountains of central Mexico. And in a very few weeks it will head back north. Look twice at these marvelous creatures as they pass through South Texas.

Tuesday, October 04, 2005

Cross Timbers Wildlife News
Great Egrets Are Grrrrrrreat
Jim Dillard, Wildlife Biologist, Texas Parks & Wildlife Department, Mineral Wells

From time immemorial, man has marveled at the beauty of birds and their feathery attire. Many cultures incorporated certain species of birds or their feathers into their religion, folklore and traditions. Bird feathers were used by aboriginal cultures to decorate clothing, drums, pipes and lances. Down feathers put into garments or bedding provided warmth and insulation from the cold. Eagle feathers were often used to represent power or recognize some outstanding deed.
Even in our own culture, we only have to look back to the turn of the Twentieth Century to be aware of our own fascination with bird feathers. During the late 1800s and early 1900s, feathers on women’s hats were in vogue. Ladies that didn’t have a lavishly decorated hat with an assortment of feathery plumes just weren’t keeping up with the Joneses. Trendy bonnets were piled high with feathers, birds, fruit, flowers, furs, even mice and small reptiles. Women’s hats sported egret plumes, owl heads, sparrow wings, whole hummingbirds and even warblers, all in the name of fashion.

The demand for feathers was so great that commercial hunting for many species of herons and egrets became a very lucrative venture along the East Coast. Certain feathers were literally worth their weight in gold. The great egret (Ardea alba) was a prime target. Relentless, unregulated hunting in the wetlands along the Atlantic Coast almost wiped them out. Thankfully, an outcry from conservation groups resulted and laws were enacted to stop the slaughter. The Audubon Society formed during this time and used the great egret as their symbol to promote conservation of herons, egrets and their habitat. Today, great egret populations have recovered and fortunately ladies hat fashions have changed.

The great egret is also known as great white egret, American egret, common egret or angle bird. They’re cosmopolitan in distribution and inhabit wetlands and coastal estuaries in North and South America, Europe, Russia, Australia, Africa, India and Southeast Asia. In the United States, their breeding range appears to be spreading northward during recent years. The sight of one of these tall, long-necked and long-legged white wading birds here in Northcentral Texas is not all that uncommon these days. In Texas, most resident birds winter along the Gulf Coast.

Of all the other white egret species, great egrets are the largest. They stand over three feet tall, have five foot wingspans and a neck that is longer than their body. The long bill is yellow; their legs and unwebbed feet are gray to black. Although they look big, they weigh only about two pounds; males are slightly larger than females. During the breeding season, long feathery plumes (aigrettes) flow from the back to beyond their tail in both sexes and are used in elaborate courtship displays. Market hunters called great egrets “long whites” because of their highly sought after long, lacy aigrettes. Their call is a raspy croaking sound - cuk, cuk. In flight, they crook their neck in an open “S” shape.

By wading and stalking prey in shallow water, they hunt for food around the shoreline of freshwater streams, lakes, ponds and wetlands and in salt marshes along the coast. Flooded fields are also favorite feeding areas. They’ll defend small feeding territories form other egrets that venture too close for comfort. Great egrets are diurnal and may feed in loose groups, but for the most part are solitary and feed during the early morning and late afternoon (crepuscular). Unlike some other heron and egret species, they don’t feed at night. They may roost together with other heron and egret species at night.

Preferred food items include frogs, crayfish, snakes, snails, insects and fish. Small mammals are also at risk and can be gulped down whole. When prey is spotted, it’s quickly dispatched by a quick jab using their coiled neck and sharp bill. Indigestible “parts” are regurgitated as pellets. On the lower part of their neck, the esophagus and trachea actually curls behind the vertebra giving these organs the shortest course to the body. This also protects the neck from injuries during a strike at prey. They sometimes use their feet to stir up the water and force prey to move or expose their location – big mistake. There apparently is no honor among great egrets since they are known to steal food items from smaller birds.

Great egrets are colonial nesters and usually nest in rookeries with other heron and egret species. Their nests are built 10-40 feet high but may be located in low brush or cattails in marshes. The platform nest of loose sticks is built by the mated pair during April or May. A single clutch of 4-5 oval, greenish-blue eggs is incubated by both sexes for 23-26 days. Unlike most birds, great egrets begin egg incubation as soon as the first egg is laid, thus young don’t all hatch at the same time. Those that hatch first grow quicker and usually get most of the food. If food is in short supply, the stronger young may kill their weaker siblings. It’s the old “survival of the fittest” scenario for baby great egrets. Young are fed by regurgitation and leave the nest in three weeks. In six-seven weeks, they’re capable of flight and are off to feed and fend for themselves. Here in Northcentral Texas, I’ve seen great egrets nesting in rookeries of cattle egrets, little blue herons, night herons and snowy egrets, usually toward the center of these colonies and in the tallest trees.

With the enactment of laws to protect great egrets and other shorebird species that were near extinction due to exploitation, populations have recovered. In Texas, all heron and egret species are classified as protected species. But, there continues to be threats to their long-term well being as more and more of their wetland and nesting habitats are being lost to development and pollution. I’m sure the recent hurricanes along the Gulf of Mexico and Atlantic coasts have taken their toll on many species of wildlife, including great egrets. Perhaps these “angle birds” can once again become a symbol for recovery and hope for those surviving this tragedy. They too have been through their own storms and came back from the brink to grace our beautiful land once again. Until next time – I’ll see you down the road and God Bless America!

Monday, October 03, 2005

Book Reviews
Hummingbirds and Chasing Neotropical Birds
BY Ro Wauer

Hummingbirds of Texas and Chasing Neotropical Birds offer the nature reader two super reads! Hummingbirds of Texas, written by three Texas naturalists, Clifford Shackelford, Madge Lindsay, and Mark Klyn, contains up-to-date information about all 18 Texas hummingbirds, along with some excellent photos by Sid and Shirley Rucker and paintings by Clemente Guzman III. This book is generally divided into two sections. The first is full of good information about hummingbird biology; finding hummingbirds; food, water and shelter; feeders; visitors, pests, and predators; overwintering hummingbirds; migratory behavior; and photographing the hummingbirds.

The second section of Hummingbirds of Texas contains a two-page spread on each species that includes identification hints, a range map for Texas as well as adjacent New Mexico and Arizona, and some excellent illustrations. These illustrations include front and back views, including both male and female views when pertinent, and also the tail that can be extremely important for identifying some species. Species include Allen's, Anna's, berylline, black-chinned, blue-throated, broad-billed, broad-tailed, buff-bellied, calliope, Costa's, green violet-ear, green-breated mango, lucifer, magnificent, plain-capped starthroat, ruby-throated, rufous, violet-crowned, and white-eared.

Scattered throughout the text are a variety of comments that any reader will find interesting and useful. Here are a few examples: "Migratory male hummingbirds reach the breeding grounds before the females in order to stake out their claim to the best territory. A hummingbird territory is an amorphous area that ranges in size (often smaller than a football field) and must include ample food sources, which are vigorously defended." "Hummingbirds are polygamous and thus do not form mated pairs. Instead, males attempt to mate with as many females as possible and leave all the nest building and brood rearing to the females." "Spiders are important to adult and nestling hummingbirds in several ways. First, hummingbirds use web fibers as sticky material to hold the nest together. In addition, hummingbirds take prey caught in the web of a spider, and they may also consume spiders and their young or eggs." And finally, "Hummingbirds can be found at cold, high elevations. While roosting through the night, some species of hummingbirds have the ability to slow down their metabolism, which cuts their body temperature in half to conserve energy, a state known as torpor."

Hummingbirds of Texas, published by Texas A&M University Press, is 110 pages and sells for $24.95 in hardback. It is a real bargain for anyone interested in birds, and especially for those of us fascinating by these flying jewels, the hummingbirds.

Chasing Neotropical Birds, by Vera and Bob Thornton, is a very different kind of book, as it highlights the Thornton's efforts of 15 years to photograph a wide variety of neotropical birds in their native habitats south of the U.S.-Mexico border. Besides a vast array of marvelous photographs, the book includes an excellent narrative about their personal adventures while photographing the birds throughout Mexico, Central America, and South America. Many of the bird photographs included in this beautiful book are seldom found in other books of this type.

A few of the most impressive photos, at least for me, included a Baird's trogon, green-crowned brilliant, and three-wattled bellbird from Costa Rica; a tufted coquette from Trinidad; a yellow-tufted woodpecker, speckled tanager, blue-winged mountain-tanager, and golden-tanager from Venezuela; a zigzag heron and toucan barbet from Ecuador; a bicolored antbird and western slaty-antshrike from Panama; a golden-hooded tanager from Honduras; a black jacobin and red-billed scythebill from Brazil; a versicolored barbet from Peru; and a yellow-billed jacamar from Suriname.

The narrative within each chapter includes enough information so that the reader understands the efforts made to capture each of the photos, as well as the details about where the authors traveled on each of their expeditions. This is truly a beautiful book and one that a birder sooner-or-later will want to include in their birding library. Especially for those of us interested in traveling to countries south of the border, it can be a very worthwhile reference. Published by the University of Texas Press, this 160-page hardback, that includes 78 color photos, sells for $34.95. It, as well as the Hummingbirds of Texas, would make for excellent Christmas presents.

Sunday, October 02, 2005

Be on the Lookout for Bald Eagles
by Ro Wauer

It is again time for the annual arrival of bald eagles into South Texas. Southern bald eagles normally return to their ancestral nesting sites in late September to November from their summering grounds to the north. They will remain through the winter months, nest in midwinter, and leave in March or April. Young birds may linger into early May, but all of the adult bald eagles and their offspring usually are long gone before the heat and humidity of summer truly set in. Rarely, one may remain year-round.

The bald eagles that nest in South Texas, along the coastal plain from Nueces County to near Houston, and around the lakes in northeastern Texas, are members of the southern bald eagle race, rather than the northern race of bald eagles that nest north of the state and as far away as Alaska. All bald eagles are long-lived and mate for life, although if one of the pair dies, the remaining bird will usually take a second mate. Adult nesters construct huge stick nests in trees usually located along waterways or along lakeshores. Sometimes those stick nests, which may have been used for twenty or more years, become so large that they literally can break down the tree branches. One nest was measured at 10 feet across and 20 feet deep.

Females normally lay two or three large, bluish white eggs, but more than two hatchlings is an exception. Incubation takes 34 to 36 days, and the nestlings are fed by both parents for about three months before fledging. So by the time the southern youngsters are flying, it is time for them to go north. More often than not, the adults will leave ahead of the uncertain youngsters.

Although bald eagles take advantage of available carrion, their diet is rather broad. Wayne and Martha McAlister write in their book, "A Naturalist's Guide: Aransas," that "food items found in the nests on the Aransas generally confirm the eagle's diet of fish and waterfowl: flounder, mullet, red drum; a white pelican, many American coots, pintails, scaups, and numerous grebes; swamp rabbits and cottontails, and one armadillo that may have been picked up a carrion. One adult eagle was seen in flight carrying a struggling scaup duck in its talons. Another was observed over Dunham Bat dive-bombing an osprey in an apparent attempt to make it drop its fish."

Adult bald eagles are truly magnificent birds, with a snow white head and tail and a huge yellow bill; these are in stark contrasts to its chocolate brown body. Its general appearance as a fierce predator also is in contrast to its true character, that of a timid carrion feeder. But anyone who has watched one of these grand creatures for any length of time cannot help but be impressed. In fact, Congress declared the "American eagle," instead of the wild turkey that Benjamin Franklin preferred, as our "national bird" on June 20, 1782.

Yet in spite of the bald eagle being established as our national bird, North American populations declined precipitously during the 1950s and 1960s, primarily as a result of egg-shell thinning caused by pesticides and heavy metals that the birds absorbed from fish and other foods. The birds were listed as endangered by the United States and Canada in 1963, and DDT, one of the most long-lived and widespread pesticides, was banned for use in the United States and Canada in 1972. Since then, bald eagles have made a remarkable recovery throughout their range.

Today, one can observed our national birds in winter in several South Texas locations. Best bet sites include a variety of fishing sites such as Coletosville Reservoir, Lake Texana, and various points along the Guadalupe and San Antonio rivers. And Dupont Victoria has constructed an observation platform along the north entrance road to the plant where bald eagles can often be seen during their winter residency. Those of us living in this part of South Texas are fortunate, indeed, to be able to see one of our most magnificent wild birds close up and personal much of the winter.