Essays

Wild On The Prairie: Birds

When daytripping in the fall and winter, watch for wintering hawks
September 20, 2006

“The crippled hawk took out for the south in the fall, hopping along the road. The neighbors a mile south saw him go, and the fellows at the pumping station down past the railroad 7 miles south saw him chasing big lubber grasshoppers.” Frances Williams, the late pioneer west Texas ornithologist (and my mother,) raised three nestling Swainson’s hawks in the 1950’s. In the Midland Naturalists newsletter The Phalarope, she reported “All three hawks left on the same day, headed for South America.”

The single-minded intent of the crippled hawk was uncompromising. Emblematic images of hawks adorned Roman standards, hawks became Egyptian gods, and boldly fluttered on early American state flags. Falconry, the “sport of kings,” mirrors the imperial self-image of the elite. The symbology of hawk images is easily understood; Hollywood used the scream of a red-tail hawk in hundreds of westerns as a transition device signifying the sharpening of the hero’s senses. (It is common knowledge that hawks have the ability to discern the twitch of a mouse whisker at a hundred yards.)

In June of 2002, on the ridge between the watersheds of the Concho and Colorado Rivers in southern Glasscock County, a pair of Swainson’s Hawks stood over a pair of young, their bodies absorbing the force of wind-driven rain. The nest, in a ten-foot tall fence-line hackberry of tumbleweed snarled shape, was otherwise exposed. When I stopped our car, Deborah and I were given a dismissive glance before the parents bent over again with heads nestled parallel, the young burrowing into the warmth of breast feathers. The family had been in tableau for quite sometime, for the barditch was filled to overflowing with a frothy scum meringue washing onto the road. Finally the smaller male left the nest, as if to draw the unwanted visitors away.

Raptors display reversed sexual size dimorphism – unlike most species of birds. Female hawks are larger, and theories have proliferated as to why. Are male hawks hyper-aggressive toward young? Is the size difference due to the partitioning of the prey resources; males feed females during incubation, and small prey is more abundant than larger. Or do females need to accumulate reserves of energy for egg production?

As raptors are long-lived “top-level consumers,” monitoring the population of hawks allows rapid assessment of the ecological quality of a local ecoregion. In the long drought of the 1990s and early 2000s west Texans have noticed a remarkable decline in summer and winter resident hawks. With the rainy June in 2003, rabbit numbers skyrocketed with predator numbers at historically low populations. Of the few Swainson’s Hawk still in the area, fledgling success was doubled the number of the year before, but were able to make only minor inroads into the prey base. After 2005 and 2006 being of average rainfall, predator numbers are high enough to start bringing prey numbers down.

Hawks are opportunistic intelligent creatures. Farmers expect hawks to accompany a thresher or combine and harvest rodents crazed by the roaring monstrous machines. A Martin County rancher observed that hawks and eagles learned to come to the crack of his .22 rifle when he combated invading prairie dogs in his haygrazer field. Hawks will come when grass and brushfires erupt, drawn by the easy capture of rodents writhing in charred anguish. A wintering Harrier learned to parallel my late parents on their evening walks so as to capture fleeing prey, and even seemed to learn to act in concert with a cat as it hunted wintering flocks of sparrows.

Raptors utilize a wide range of hunting styles – from the round-winged accipiters (chicken hawks) plucking birds off of perches as they duck through forests, to swept-back winged falcons dispatching fast-moving prey in mid-air, to short-winged kestrels hovering and dropping onto pocket mice and grasshoppers, and groups of Harris’ Hawks chasing rabbits like a pack of coyotes. In the winter, big Red-tailed Hawks often wait for an even larger Ferruginous Hawk to make a successful kill, then swoop in with larcenous results.

Predator and prey have complex relationships. Prey species often mob hawks. For example, a dozen kingbirds will join in a screaming match, swooping and bopping a territory-trespassing hawk until it leaves. Mobbing does not always occur, however. My mom built a 10 by 6-foot brushpile out her kitchen window to provide cover for birds visiting her feeding station. Sharp-shinned Hawks frequently dove into the swarm of feeding sparrows and caught one. The Hawks would then sit on the brushpile and slowly pluck their lunch. By the time they would begin to tear into the meat, all the sparrows would be back feeding five feet in front of the hawk, or sitting in the brushpile even closer to it. “If you have a sharpie visiting your feeders, you are a successful birdfeeder,” she always told people who called her for advice on how to “get rid of those evil hawks.”

Back when most of the United States population was rural, hawks were killed on sight because they considered free-range chickens easy prey. A few people hold on to their grandparent’s prejudices and still shoots hawks, and do so driving down rural roads until perched targets are found. Such folks are mindless target hunters with no respect or knowledge of the spiritual value of hunting, and besmirch the honor and dignity of true sportsmen.

During September and October the population of hawks in West Texas increase. They come to spend the winter, and if we have had sufficient rains for vegetative growth and seed production for rodent food, we have plenty of rodents for the hawks. Most will be Red-tailed Hawks. A number of Ferruginous Hawks will also be present, but it is a rare and wonderful day when a Rough-legged Hawk is found. We already have Kestrels back in the region. A Peregrine Falcon also just arrived in town. Prairie Falcons should soon be arriving along with the accipiters, the smaller Cooper’s and Sharpshinned Hawks. Hawks are cool!