November 09, 2005

Researchers ponder rise in armadillo sightings

by Tim Crosby

CARBONDALE, Ill. — He's known by many names, including "Texas Speed Bump," "Opossum on a Half-Shell" and "Hoover Hog." But the humble armadillo, the only mammal that grows its own armor, may add another moniker to this colorful list: Illinois resident.

Researchers at Southern Illinois University Carbondale are taking notice of the increasing number of armadillo sightings this side of the Mississippi River. A recent survey of Illinois residents revealed dozens of sightings during the last few years, and many recovered carcasses.

The insect- and road-kill-eating critter with the long nose and football-shaped body may not inspire the same sense of awe as the cougar, an animal known to make occasional appearances in Southern Illinois though does not live here. But SIUC wildlife scientists want to know where armadillos are living, how they got here and most of all, if they are here to stay.

"Armadillos are on the increase in Southern Illinois," said Clay Nielsen, a wildlife ecologist at the SIUC Cooperative Wildlife Research Laboratory. "Their distribution has changed over time, like many species, and they seem to be moving north throughout their range. But it's an armored mammal, which is strange to see in the Midwest."

Nielsen spotted one of them on the Illinois side of the Mississippi River near St. Louis. His sighting was unusual in that the animal was alive. Most sightings occur post-mortem, usually along a road following an unfortunate encounter with an automobile. Local residents brought several such specimens to the wildlife lab in recent years.

A native of South and Central America, armadillos migrated steadily north during the past two centuries. First reports in the United States surfaced in the mid-1800s in Texas. In more recent times, this variety – known as the nine-banded armadillo – became commonplace in the southern United States, inspiring many schools and clubs throughout that region to adopt them as mascots.

Some reports of armadillos in Illinois stretch back to the 1970s. But an increase of reported sightings within the last few years prompted the Illinois Natural History Survey recently to conduct a survey of known nature watchers in Illinois. The survey revealed nearly 80 sightings between 1999 and 2003, mostly from Southern Illinois.

Nielsen, whose expertise lies in carnivores and white-tailed deer, routinely answers media inquiries about cougar sightings in the area. While he determined that cougars are not residents of Southern Illinois, the armadillo issue is a mystery at this point.

"We're not entirely sure why they're here or how they got here," he said.

If an armadillo gets to Southern Illinois, however, there's reason to believe he'll like it here, Nielsen said.

"They eat insects, so basically there's lots of food for them here, and cover is plentiful," he said. "Whether this is an established population or relatively few showing up is unknown. It's too early to say."

The main limitations are temperature and rainfall. Scientists estimate the creature cannot establish a breeding population in places where the average temperature in January is below 28 degrees. And the armadillo requires a constant source of water.

Armadillos have some endearing qualities. They are relatively unafraid of humans, yet can run surprisingly fast. They also are known to jump several feet into the air when startled. Despite common beliefs to the contrary, armadillos and opossums are not members of the same family, nor are armadillos marsupials. They are related to anteaters and sloths and their offspring are almost always a set of identical quadruplets.

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