Fewer Cowboys, More Deer

A kind reader forwarded an old article from "Texas Wildlife: Newsmagazine of the Texas Wildlife Association," written by Charly McTee, and published in 1992. The article was titled "Where have all the cowboys gone?" I found its argument compelling, and since it has a tie to Kerrville's history, I thought I'd share parts of it here with you.

I'm old enough to remember when there were a lot more folks employed in ranching. While we have ranchers today, and a lot of young people who wear western wear, it seems to me there was a time, when I was very young, when many of the folks you'd encounter around town wore boots (and even spurs) -- not as a fashion choice, but as a practical choice. 

In those days more people had jobs which kept them on horseback, working livestock. They weren't trail drivers, as the old-time cowboys were, but they worked from horseback most every day, especially during certain seasons of the year.

Likewise, when I was younger, it seems like we didn't have nearly as many deer in our neighborhoods as we do today. Even as recently as the early 1990s, when one of our nephews visited from Houston and wanted to see deer, we had to drive to a big field on the outskirts of town. It took some searching to find the boy a deer at which to look.

Today one bumps into at least three deer taking the trash to the curb -- and five more when checking the mailbox.

What's changed?

According to McTee's article, the change happened because of work done right here in Kerrville at the USDA's Knipling-Bushland U.S. Livestock Insects Research Laboratory: the program that led to the eradication of the screwworm.

A screwworm is something you'd find in a horror movie, "the most horrible thing imaginable," McTee writes. "The process is simple enough: a fly lays its eggs on an open wound in an animal -- a wire scratch, antler gouge, navel sore, or even a tick bite. The eggs hatch into larvae, which then sustain themselves by feeding on the flesh around the wound -- in effect, consuming their host while it is still alive. Since the wound stays open, more flies can lay their eggs, and the process goes on. As the larvae mature, they pupate, fall to the ground, and hatch out into still more flies, and the process continues until eventually the animal dies and is consumed."

I told you it was horrible.

"Any animal larger than a cottontail rabbit could support screwworms long enough for the larvae to mature," meaning pets, livestock, and deer were targets of the pest. Humans, too, were occasional victims.

Because of the danger of the screwworm, ranchers had to visually inspect every animal "at least twice a week during fly season," or face catastrophic losses.

Such labor-intensive inspections meant a lot of people working on horseback in this part of the world.

The early work to eradicate the flies was done in Menard, in 1937-39. Dr. R. C. Bushland had developed a technique for artificially raising screwworm flies -- initially to test medications to fight the pests. Another scientist there, Dr. E. F. Knipling, noticed there were "relatively few screwworm flies in nature. Another curious observation was that the female screwworm fly, the egg-layer, seemed to breed only once."

An idea was formed: if the female screwworm flies bred with a sterile male, "then the eggs would not hatch, and there would be no larval infestation."

After World War II, the lab was moved to Kerrville. Another scientist, Dr. A. W. Lindquist, "happened across a scientific paper which described radiation producing sterility in flies."

Knipling and Bushland began experiments to see if sterile male screwworm flies could exterminate a wild population of screwworm flies.

And the idea worked, though getting funding and acceptance of the idea took many years.

Sterile flies in boxes were dropped from airplanes, systematically blanketing areas. And the screwworm menace eventually came under control.

With less need to inspect livestock twice a week, fewer were employed in that occupation. With fewer screwworm flies, more deer survived, multiplying and moving into town with us.

Meaning: fewer cowboys, more deer. Happy hunting!

Until next week, all the best.

Joe Herring Jr. is a Kerrville native who remembers a lot of the folks who worked at the USDA Laboratory over the years.  This column originally appeared in the Kerrville Daily Times November 7, 2015, just in time for hunting season.