There is limited information about the Tucson shovel-nosed snake, a red-and-black ringed, foot-long creature that the U.S. Fish & Wildlife decided Tuesday deserves a closer look.
“It’s very hard to study,” said Marit Alanen, the lead U.S. Fish & Wildlife Service biologist for the status review.
The snake, which uses its snout to burrow into sand to hide from enemies or seek food or moisture, has not been seen closer to Tucson than Picacho since 1979, said Phil Rosen, a herpetologist at the University of Arizona who has been studying the snake for about 30 years.
“There are no photographs, no specimens and no reliable sightings,” Rosen said.
The snakes still live near Florence Junction, east of Queen Creek, and possibly near the Casa Grande ruins in Coolidge. Through the mid-1970s the snakes were common along Avra Valley Road northwest of Tucson, where two or three per night could be found, said Rosen, who called the decline “stunning.”
“The subspecies is really on a fast track toward extinction,” he said.
In the 2004 petition to add the snake to the endangered species List, the Center for Biological Diversity cited urban sprawl and agriculture as key threats.
Rosen agreed that agriculture and urban sprawl contributed to the snake’s decline, but other species have not declined as much in those same areas, he said.
“So there’s some mystery as to what’s going on,” Rosen said.
The decline seems to be among species that rely on the sandy creosote- and mesquite-laden desert floor.
The desert horned lizard, which lives in those areas, has also declined. But the regal horned lizard, which lives across a broader spectrum of desert including higher paloverde and saguaro desert, remains abundant, Rosen said.
Other species that may be in decline on the Sonoran Desert floor include the kit fox, burrowing owls and the Le Conte’s thrasher, which Rosen called America’s only pure desert bird.
“All of these have very similar competing species that may be benefiting and moving in” or hastening the declines, he said.
The decision to review the status of the snake does not mean Fish & Wildlife has taken a stance on the snake, said Marit Alanen, a Forest Service wildlife biologist.
The service Tuesday announced a status review that includes a 60-day period during which the public can comment about the snake. But the service needs information from scientists more than comments from the general public, Alanen said.
Fish & Wildlife will review all it can find about the snake, including a study of the impact of agriculture and residential development, Alanen said.
The Endangered Species Act requires the government to either recommend or reject the protection within one year.