The desert tortoise gnawing on Daniel Marchand's shoelace has plenty of company at this reptile sanctuary.
The Phoenix Herpetological Society, where Marchand serves as curator, has taken in 25 tortoises in the past two weeks - the number it usually receives in six months. Most are turned in by people leaving foreclosed homes, he said.
"We're finding them abandoned, dumped or brought to us," Marchand said. "Or they call and say they're going to lose their house at the end of the month and have to get rid of their tortoise."
As Arizona reels from the housing slump, desert tortoises kept as pets are increasingly becoming victims as families either turn them over to shelters or release them. Experts say doing the latter can be a death sentence for pet tortoises, which often can't fend for themselves. The tortoises also can spread disease to wild populations.
Marchand said 80 percent to 90 percent of the tortoises his sanctuary receives are there because of home foreclosures.
"It forces people to downsize to condos with no backyards from houses with big backyards," he said.
It's illegal to remove tortoises from the desert, though that often happens. It's more common, and also legal, for people to adopt tortoises that are already kept as pets or the offspring of those tortoises, Marchand said.
"They're safe, docile and friendly," Marchand said. "They don't need to be coddled every day, and they'll come to you if you call."
Cristina Jones, coordinator of the state Game & Fish Department's Turtles Project, estimated that tens of thousands of desert tortoises are kept as pets around Arizona.
The Phoenix Herpetological Society finds homes for tortoises brought there, but some owners simply leave the reptiles in the desert or in neighborhood parks. The Arizona Game & Fish Department recently issued a warning that dumping or abandoning tortoises is a crime.
Jones said pet tortoises can transmit diseases to wild tortoises. Released tortoises often die because they are unfamiliar with the area and can't find food and water.
"It's important to know that it's illegal," said Cecil Schwalbe, a research ecologist with the U.S. Geological Survey's Sonoran Desert Research Station in Tucson. "The wildlife doesn't need another sick animal in the desert."
Russ Johnson, president of the Phoenix Herpetological Society, said tortoises in captivity can pick up ailments such as upper respiratory tract disease, which is suspected of wiping out whole regions of desert tortoises in California and Utah.
The Game & Fish Department has teamed up with Johnson's group to create a desert tortoise adoption program.
It costs $50 or less to adopt a tortoise, Johnson said, but the society will first confirm that those wishing to adopt have suitable living space.
"We don't want to just give them away; these are amazing creatures," Johnson said.