The Nature Writers of Texas

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

Thursday, October 23, 2008

Sandhill Cranes Are Returning to Their Wintering Grounds
by Ro Wauer

October marks tat time of year when sandhill cranes are staring to move into their wintering grounds throughout South Texas. It is wonderful to have these large, graceful birds back in our fields and pastures. They will remain all winter, leaving for their northern nesting grounds in late April and early May. From now until May, one can find hundreds of these birds by driving the roads throughout the region.

Unlike the more famous whooping cranes that also winter in South Texas at Aransas National Wildlife Refuge and on adjacent coastal flats, sandhill cranes prefer old fields and pastures. Their needs are very different. While the whoopers overwinter only in wet coastal marshes, feeding on fish and other marine life, as well as marsh plants, acorns, and grains, sandhills prefer newly planted or harvested corn, sorghum, and grains. They may even range into semiarid areas west to the Big Bend country.

Our returning sandhill cranes often possess an odd color pattern, especially when they first arrive; their feathers are rust colored from the iron-rich feeding grounds where they spend their summer months. Normal sandhill crane plumage is overall gray with a whitish throat and cheeks, a bare reddish cap in adults, and dark legs, Whooping crane adults are all white except for a black facial pattern and reddish cap. In flight, whoopers display obvious black-and-white wings, while flying sandhills are all gray, except for their whitish throat. Both fly with their heads stretched for out and legs extended; great blue herons and egrets, also large birds that are sometimes confused with cranes, normally fly with their necks bent so that their head does not extend.

Sandhill cranes may be one of our most expressive birds. They often can be heard at a considerable distance, talking to one another in their unique call, a long, rolling, hollow rattle, like “garpoooooo.” Whether in flight or feeding in a field, they seem to spend a great deal of their time communicating.

Although huge flocks of 50 to 100 or more birds can be found regularly in South Texas, these groups can usually be broken into rather distinct family groups. Especially when they first arrive in our area, groupings of adults and juvenile are commonplace. The young generally remain with the adults all winter and gradually, by the time they are ready to head north again, mature to the point that they are difficult to distinguish from the adults.

Normally sandhill cranes mate for life, and as their mating season draws close, they often can be seen dancing before their mates. Although their mating displays in Texas are less elaborate than the dancing that occurs on their breeding grounds, it is till worthy of our observations. Courtship involved loud calling and marvelous dances with head bobbing, bowing and leaping, grass tossing, and running with wings extended.

It is good to see sandhill cranes returning to South Texas.

Thursday, October 16, 2008

Blue Jays Are More Active Than Usual
by Ro Wauer

Numerous blue jays, probably two or three family groups that have flocked together since nesting, are spending an inordinate amount of time in my yard, especially at the birdbaths. That behavior for the normally shy and elusive blue jays is unusual. Several of these jays still possess juvenile plumage, not the bright blue and white features so evident in the adults. Even their crest and black chest-band have not yet fully developed. The adults, however, show all the typical blue jay features: blue back and crest, blue wings with white wing bars, blue tail with black bands, whitish cheeks, and grayish underparts with a black chest-band.

The blue jay is one of our best known birds, common throughout the eastern half of North America. In Texas, blue jay distribution extends west through the Edwards Plateau and northeast to the eastern portion of the Panhandle. They also occur southward to and beyond Corpus Christi, but they are only vagrants in the Rio Grande Valley and in far West Texas.

Blue jays, perhaps more than most other bird species, engender mixed feelings in people. Although they are often admired for their color, togetherness, and tenacity, they often are disliked as thieves and loudmouths. Jays in general are well known as predators on other bird life, often preying upon smaller birds, their eggs, and nestlings. They also fed on a wide variety of other materials, whatever animal and plant foods they can come upon. They accept almost any handout offered from seeds to table scraps. In the wild, acorns are important in their diet, and they cache acorns in out-of-the-way places for later use. They hide these nuts in crevices above ground as well as in holes they dig in the ground. This caching behavior is common to all jays, crows, ravens, magpies, and nutcrackers, all members of the Corvidae family. The advantage of such behavior is that it allows these birds to survive even during hard times, even during periods of drought. Northern jays are able to nest in winter, long before the abundant seasonal foods are available.

All of the jays, of which that are nine resident species in North America (blue, gray, Steller’s, brown, Mexican, and pinyon jays, and western, Florida, and Island scrub-jays), are well known loudmouths. In fact, the harsh “jay jay jay” calls of the blue jay are where their name was originally derived. But our blue jay has numerous other calls. In “The Bird Life of Texas,” author Harry Oberholser states that the blue jay’s “song is a series of notes considerably keyed down to low, sweet whistles, lispings, and chipperings. Usually the bird performs this jumble while concealed in tangled vegetation or on interior branches of a tree. This song is heard infrequently from March into June.” He also claims that jays possess a slurred sound like “jeer” or “peer.” And “usually in spring the bird whispers a pleasing teekle, teekle that is often joined with a whee-oodle, the later commonly called its creaking wheelbarrow note. Members of foraging groups, particularly in autumn, converse with a chuckling kuk.”

Oberholser also points out that blue jays often sound like other birds. The “bird’s teerr cry sounds like that of the red-tailed hawk; the similarity of the screams is apparently more coincidental than imitative. Another call is a low throat rattle.” However, whether or not the jay’s abundant calls are intended to imitate other birds, they do succeed in attracting attention, and some of that attention is from some of the small birds, such as chickadees and titmice, species that are susceptible to larger predators. One can’t help but speculate!

Thursday, October 09, 2008

Shrikes Are Back! Winter Isn’t Far Behind
by Ro Wauer

Several loggerhead shrikes are back on their wintering grounds. These little predators are once again back on fence and utility lines throughout South Texas. Although a few actually remain year-round, the winter population is much greater. The majority of our wintering birds migrate north in spring to nest elsewhere. But now, their harsh trill or rattle calls can be heard at almost any open field.

Shrikes are easily identified by their stocky, short-necked appearance, short wings, and black-and-white colors: black wings, tail, and mask; gray back; and white underparts and wing patch evident in flight. Its black mask makes it look like a little avian bandit. And it flies in a straight line with fast on-and-off wing beats.

The loggerhead shrike is most unusual in a number of ways. Unlike most other songbirds, it preys on birds, mammals, lizards, and small snakes, as well as a wide variety of insects. But because it does not possess sharp talons to tear its prey apart, as do the larger raptors (hawks, eagles, falcons, and owls), it must utilize a different technique. Therefore, it has learned to impale its prey on sharp yucca leaves, cactus, and other thorns, barbed wire, and such. It can then feed on the carcass for several days. It is not uncommon to find several prey species impaled on a fence or on a certain spiny shrub. The prey is almost always suspended with its head up and body hanging down. This impaling behavior has given the loggerhead shrike the name “butcher bird.”

Recent studies have shed new light on the shrike’s unusual behavior. On its nesting grounds where impaled prey are most evident, the numerous impaled prey specimens represent the male shrike’s hunting prowess in attracting a female shrike. Males with the larger number of impaled prey are first to attract a mate. Although both sexes impale prey year-round, decorated spiny structures are most common on their nesting grounds.

As many as 72 species of shrikes are known worldwide, but only 2 occur in North America, the northern shrike of the northern boreal forests and the loggerhead shrike of the central and southern states. All of the world’s shrikes are small to medium-sized birds, 7 to 10 inches long, with large, broad heads and stout bills that are strongly hooked and notched near the tip. The notched bill is very similar to that of falcons. It includes a toothlike structure on the cutting edge of the upper mandible that corresponds to a notch on the lower mandible. These “teeth” are important in the shrike’s killing ability. It is able to kill prey with a series of sharp bites with its strong bill which can sever neck vertebrate of its prey.

Small birds can be swallowed whole, and their feathers and bones later regurgitated, but larger prey are carried to favorite sites and impaled where they can be eaten at their leisure. Shrikes are fascinating birds, and the number of loggerhead shrikes that over winter in our area offer us a great opportunity to watch a most unusual songbird.

Thursday, October 02, 2008

The Fall Season is All Around Us
by Ro Wauer

Although South Texas has only a few broadleaf trees that turn color in fall, numerous other signs of fall are present for those of us that recognize those changes. And those changes can vary considerably from falling leaves to migrating birds and monarchs to fall blossoms that are extra attractive to hummingbirds and butterflies.

Already we are experiencing the southward movement of a wide variety of birds, from waterfowl and shorebirds to a huge diversity of songbirds. And for those of us who watch carefully for our returning wintertime species, we already are finding American kestrels, loggerhead shrikes, and a few warblers on their wintering grounds. My favorite of all those is the American kestrel, a small falcon that haunts our fields and pastures, usually found sitting on a high post or on utility lines. There they watch carefully for movement of a small rodent or snake, grasshopper, or other insects that they can dive upon, capture with their sharp talons, and haul back to a perch to consume their catch. The majority of our early kestrels are females that usually arrive ahead of the smaller but more brightly marked males to claim a territory. The arriving males usually find a less preferred site.

Right now, during the last few days of September and early October, migrating hummingbirds are at their peak. Any hummingbird feeder could possibly host one or two dozen ruby-throated hummers, a few black-throated hummers, the resident buff-bellied hummer, and any unusual species that happens by. Anna’s, Allen’s, broad-tailed. and rufous hummingbirds are possible.

Fall is the best time in our area for butterflies. There already has been a huge build-up of sulphurs. My garden currently is playing host to dozens of large orange and cloudless sulphurs and fewer numbers of lysides and southern dogfaces and little yellows. Pipevine and giant swallowtails also are commonplace right now, as are queens and a few skippers. But the huge numbers of butterflies can be expected by mid-October and into December when crucitas (Eupatorium odoratum) bloom. These marvelous shrubs are true butterfly-magnets, and their flowers are preferred over any other flowers that bloom in fall.

More species of butterflies can usually be found in our area during October and November than in any other period during the year. If my yard is an example, I recorded 68 species in 2007, 69 in 2006, and 71 in 2005. October and November is that time of year when a number of species appear that emerge locally only in fall or move northward en mass from more southerly areas. Some of those fall-only butterflies include Lacey’s scrub-hairstreaks, Julia and zebra heliconians, common mestras, white peacocks, soldier, and Dorantes longtails. In 2007, probably because of the amount of rainfall, the number of Julia heliconians in our yard was unbelievable. From November 9 to 13, we counted as many as 300 individuals daily. So far this fall there has been only one or two Julias per day. Perhaps that number will increase during the next few weeks.

But what is so extra species this time of year is the number of strays that can occur. Although some of the stay species may appear for only a few minutes, a few hours, or a few days only, before moving elsewhere, they can add considerable excitement while present. Some of my most exciting fall finds these last few years have included Florida whites, white and yellow angled-sulphurs, statira sulphurs, Mexican yellows, tailed oranges, dingy purplewings, zilpa longtails, white-patched skippers, Erichson’s white-skippers, and violet-banded skippers.

Fall of 2008 will undoubtedly produce more excitement. As the butterfly numbers increase and the wintering birds return, there is little doubt that nature-lovers have a lot to look forward to.