Sunday, March 13, 2005

Sonoran pronghorn

SONORAN PRONGHORN: Making a comeback:

Little more than a century ago, tens of thousands of Sonoran Pronghorn roamed the desert wilds of the American Southwest, but hunting, changes in climate and factors associated with human intervention have impacted the number of animals.

“Three years ago, there were 300. Then a drought hit - only 1.1 inches of rain fell over a 13- month period - and 90 percent of the population was lost,” Eslinger said. “Our population plummeted to only 18 animals.”

A survey done in December counted 39 Sonoran pronghorn in the United States, “so we have actually doubled the number in the past two years,” he said. “There could be several more born before this cycle is over.”
This recovery is a combination of habitat recovery and old fashioned breeding programs. Greater care for the desert habitat and better hunting regulations have laid the groundwork. That's what ESA does. Recovery is about breeding programs and reintroductions. There's a difference, and an important one, between stopping the decline and starting the recovery.

Pronghorn antelope are one of the special things in the world. The second fastest land mammals (after cheetahs), the family is endemic to North America. It's as fast as it is because there used to be cheetahs here to chase them. That's evolution at work.

They also have an interesting place in the evolution of mammals. The difference between horns and antlers is that antlers are shed each year while horns are permanent. Pronghorns have a bony core which isn't shed, but a sheath which is shed annually. Are they on the antler side or the horn side? Most people think they're horns with an outside which sheds, but it does make things complicated.

Life itself is complicated, and biology is about finding how it all fits together.