The Nature Writers of Texas

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

Sunday, September 24, 2006

It Is Again Time for Monarchs
by Ro Wauer

The fall monarch migration through our part of Texas is due any day now. The major portion of the southbound monarchs that pass through our area can be expected by mid- to late September and to continue through most of October. The majority of the migrants will move out of our region into Mexico by the end of October. And this year should be another big year, in spite of previous concerns about impacts to their wintering grounds in Mexico.

Good news about monarchs comes from an article by Mike Quinn, TPWD Invertebrate Biologist, in "The Texas Nature Tracker," a TPWD newsletter. Mike wrote that surveys of wintering monarch colonies by Mexican biologists in the Monarch Butterfly Biosphere Preserve in Michoacan in 2005 revealed numbers "nearly tripled in size, from a record low of 2.19 hectares the previous winter to 5.92 hectares of occupied forest habitat last winter!" He added that "The annual benchmark is represented by the size of the forest area occupied rather than the actual number of insects due to the widely disparate estimates of between 10 and 50 million monarchs per hectare."

The monarch preserve lies at about 10,000 feet elevation, where periodic freezes occur. Last winter was relatively mild and the wintering monarchs were not subject to deadly freezes as they had during the previous winter. That combined with loss of habitat had resulted in some serious declines in the number of over wintering monarchs.

But by mid-March 2006, Texans were seeing above average numbers of northbound migrants, including groups, rather than single monarchs. These spring migrants were "on the final leg of a sojourn" that had "begun half a continent and over a half year ago." Mike pointed out that these migrants, "composed of worn individuals approaching the eighth month of their adult life, and coincides with the insect’s lowest annual population level." The spring migrating females that found milkweeds (larval foodplants) layed eggs and continued northward, although the majority of these old-timers soon perished. It was their offspring and their offspring that continued northward into the Great Plains, the Midwest, and further north into Canada.

Mike reported that "by the end of June 2006, the monarchs were still expanding to new locations in Canada with many observers reporting above average numbers of all stages of monarchs!!! All individuals in terms of monarch observations and current weather conditions in the upper Midwest suggest that this might be a banner year for the mighty monarch butterfly!"

Observers interesting in sending their monarch observations can do so either to Texas Monarch Watch, 3000 S. IH-35, Ste. 100, Austin, TX 78704, or directly to Mike Quinn at mike.quinn@tpwd.state.tx.us.

Sunday, September 17, 2006

Raptor Migration Can Be Spectacular in South Texas
by Ro Wauer

As the mobs of hummingbirds passing through South Texas begin to subside, another group of migrants, the much larger raptors - the hawks, kites, eagles, and falcons - can be expected. Raptor numbers should peak in late September, and on select days up to 100,000 hawks in continuous flights of over 40 miles long are possible in South Texas. That is something to see!

It is estimated that 95% of North America's broad-winged hawk population migrates southward along the Texas central Gulf Coast. Moderate numbers of Swainson's, red-tailed, Cooper's, and sharp-shinned hawks, Mississippi kites, American kestrels, peregrine falcons, and smaller populations of ferruginous, Harris's, red-shouldered, and zone-tailed hawks, bald and golden eagles, merlins, and white-tailed and swallow-tailed kites move through our area as well. Mississippi kites have already been evident over the treetops in area towns, and I also have had a report of a hundred or more individuals over Schroeder.

But the most outstanding spectacle of the raptor migration is a circling flock of broad-winged hawks, especially when several hundred of these hawks begin to leave a preferred overnight roosting site at one time, usually about 8:30 A.M., and slowly ascend by circling to a point where they are out of sight.

The broad-winged hawk is a fairly small hawk, built very much like our common red-tailed hawk but with a banded rather than an all reddish tail. It is a common nester throughout the eastern deciduous forests of North America. And like many of our raptors, it is a neotropical migrants that goes south for the winter. Broad-wings spend their winter months from southern Mexico south to Peru and Brazil.

Hawk migration occurs in many parts of the world, and organized hawk watches at a few key sites have provided some amazing statistics. The best known historic sites include Pennsylvania's Hawk Mountain and New Jersey's Cape May Point, but in recent years, Texas sites have produced even greater numbers. The single most productive one is Hazel Bazemore County Park near Corpus Christi, where over one million hawks are known to cross over each year from mid-September to mid-October. Hawk watchers at Hazel Bazemore, a geographical chokepoint, have recorded up to 100,000 individual hawks in a single day. Hazel Bazemore County Park is located west of I-77, on SH 624, just beyond Calallen. Participants and onlookers are welcome.

Other organized Texas hawk watches occur at Smith’s Point near Anahuac National Wildlife Refuge; Bentsen-Rio Grande State Park (best in spring); Santa Ana National Wildlife Refuge; Padre Island, especially good for peregrines; Dangerfield State Park near Longview; and Devil’s Backbone near Wimberley. But all-time high counts have been recorded farther in Veracruz, Mexico. A grand total of 5,077,152 raptors were tallied in 1999.

Hawk watching can be a most exciting outdoor activity, and one in which anyone, birder or not, can participate.

Sunday, September 10, 2006

Beetles, Beetles Everywhere
by Ro Wauer

Every year in late summer beetles are commonplace. But this year, probably relating to our odd weather pattern, they seem to be more numerous than usual. At least a dozen species of beetles have been found in my backyard the last few weeks, and it doesn’t take a great deal of searching. For instance, four different species share the overripe watermelon that I have placed on my feeding tray that I use to attract butterflies. The most unusual of these beetles are two long-horn beetles. One is large (about an inch in length) orange and black with equally long orange-and-black segmented antennae. Truly a marvelous creature!

The second long-horned beetle eating away at the watermelon is only half the size of the orange and black species, but is even more colorful. It is blackish blue with numerous tiny yellow, rectangular spots. Its antennae are also the length of its body. I have been unable to specifically identify these beetles, other than knowing that they are both long-horn beetles, members of the family Cerambycidae. The two other beetles sharing pieces of watermelon are more easily identified: June beetle, a heavy-set, rounded insect with a maroon upper side and less than an inch in length, and an eyed click beetle, blackish with tiny white spots and with an obvious pair of eyespots on the head.

Spending a few minutes wandering around the yard will likely turn up several more beetle species. I can expect one or two tiger beetles, scarabs, carrion beetles, stag beetles, darkling beetles, wood borers, lady bugs, weevils, and fireflies, all beetles in the insect order Coleoptera. Why so many kinds? Probably because beetles are the largest order of insects, an amazing diversity of species that utilizes every possible niche. In North America alone there are 115 families and more than 27,000 species. World-wide, there are more that 290,000 of them. Beetles are the largest order of living things, according to Richard White, in his book, Beetles, one of the Peterson Field Guides.

Yet, in spite of the huge variety of beetles, they are fairly easy to separate from other insects. All possess rather horny or leathery front wings (elytra) that usually cover the entire abdomen and nearly always meet in a straight line down the back. Beetle antennae, according to White, are highly variable, "often threadlike, sometimes sawtoothed, or with terminal segments variously enlarged." And beetle mouthparts are designed for chewing.

There are a few insects, however, that can be confused with beetles. True bugs, for instance, can resemble beetles. But bugs (Order Hemiptera) can easily be identified by their overlapping wing covers, not equally divided on their back like beetles. Hoppers, earwings, and roaches have similar characteristics. But only beetles have equally divided wing covers.

White also provides a perspective on the number of beetles within all the families found in North America. Seven families contain more than a thousand members. In declining order they include rove beetles (3100), snout beetles (2432), ground beetles (1700), leaf beetles (1475), scarab beetles (1375), darkling beetles (1300), and long-horn beetles (1100). By anybody's count, that's a lot of insects.

I have not been able to find details of what species occur only in Texas, but White does include the Texas beetle that is a single member of the Family Brachypsectridae (ugh!) occurring only from Texas to California. The Texas beetle is a tiny, flattened, ridged insect that is yellow-brown in color. Sorry, but not all that impressive!

The editor's note in White's book states: "Of the approximately 1,000,000 known species of animals on earth, about three-quarters, or 750,000, are insects. Of these, perhaps two-fifths, or 300,000, are Coleoptera, and therefore a beetle-watcher need never run out of new and exciting finds." One of every living creature is a beetle! My yard beetles prove the point!

Sunday, September 03, 2006

Eastern Kingbirds Pass Through in Flocks
by Ro Wauer

Among my favorite Neotropical migrants this time of year is the black-and-white Eastern kingbird. It looks a little a scissor-tailed flycatcher but lacks the long tail and pinkish sides. And Eastern kingbirds are just as stately as the scissor-tails, but with a very different dress. They possess all-white underparts, black face and cap, dark back and wings, and a black tail tipped with white. They also possess a narrow orange-red crown patch that is seldom visible. And they have a very distinct song, a stuttering "kip-kip-kipper-kipper; dzee-dzee-dzee." Eastern kingbirds nest throughout much of our area in small numbers. They seem to prefer moist areas, often nesting in low trees along the water's edge. For instance, I have found nesting birds pairs along FM 1289 between Port O'Connor and Port Lavaca.

But what makes this bird rather special is its varied behavior at different times of the year. They arrive along the central Gulf Coast as early as late March, although they cannot be expected in numbers until mid-April. These northbound migrants often occur in flocks of several dozen to 100 or more. Most pass through our area, continuing northward to their more northern nesting grounds that extend from Washington State eastward through central Canada into the Maritime Provinces and south to central Texas.

When nesting, they occur in solitary pairs and vigorously defend their nesting territory against all other kingbirds and much larger birds as well. They become extremely aggressive, even driving off crows and passing hawks, landing on their backs and giving them a peck or two. They also have marvelous displays in midair. Their courtship flights consist of flying up and down, zigzagging, doing backward somersaults and other aerial robotics, all with quivering wings and a widely spread tail. They have even learned to reject the cowbird eggs that cowbirds lay in the nests of many birds the same size as kingbirds. There are very few records of cowbird parasitism for Eastern kingbirds.

Like all flycatchers, their principal diet during their nesting season is insects. Most are captured in flight, usually by the kingbird flying up or out from a lookout perch; they also will hover over the ground, searching for insects, and then pounce on unsuspecting prey. But just as soon as their nesting season terminates, they revert to their winter pattern of flocking with other Eastern kingbirds. And they also begin to feed on fruit that is usually abundant in late summer and fall.

By early September, we find most Eastern kingbirds in flocks, flying southward toward their wintering grounds. They will often rest of wires along the highways or bare treetops at the edge of our pastures. But they gradually drift southward, so that by early October, they have pretty well left our area, although occasional flocks can be found to mid-October. On their wintering grounds in South America, they gather in even larger flocks, sometimes in the hundreds. And unlike their feeding patterns in the United States, they spend much of their time foraging for berries in the tropical forests.

There is little question about the behavioral diversity of this fascinating flycatcher. Plus, it is one more of our birds that we share with our neighbors to the south.