Rim Country Garter Snake Labeled Endangered

Feds decide Northern Mexican Garter Snake is endangered — but the Fish and Wildlife Service has no money to protect it



Photo by Jeff Servoss, U.S. Fish and Wildlife Service

The Northern Mexican Garter Snake holding out in Tonto Creek and the Verde River is endangered after all, according to the U.S. Fish and Wildlife Service.


Turns out, the Northern Mexican Garter Snake holding out in Tonto Creek and the Verde River is endangered after all, according to the U.S. Fish and Wildlife Service (USFWS).

Our bad, concluded the agency this week in response to a lawsuit challenging its previous decision not to list the water-loving reptile, that once undulated through most of the streams in Arizona but now may survive in Rim Country and some isolated stock ponds and southern Arizona streams.

Good news for the snake.

Sort of. Now the fine print.

Specifically — the federal agency charged with protecting endangered species says it doesn’t have any money to actually do anything to protect the once-widespread garter snake subspecies. The striped snake can grow up to four feet long and lives on a diet of fish, frogs and crayfish — hunted on the bottoms of streams and ponds. In a pinch, they’ll venture onto land to gobble rodents, lizards and even earthworms.

“The Northern Mexican Garter Snake faces significant threats in the United States and Mexico,” concluded USFWS Arizona Field Supervisor Steve Spangle, “however, we don’t have the resources at this time to engage in the listing process for all species nationally that warrant Endangered Species Act protection.”

The empty victory for the snake comes at the end of a convoluted process, in which the Tucson-based Centers for Biological Diversity goaded the federal government into action.

The environmental group asked the wildlife service to list the snake as endangered back in January of 2006, was rejected, and kept fighting — and won the concession this week.

The garter snake subspecies once occurred in streams and ponds throughout Arizona and Mexico’s Sierra Madre mountains. The snake favors thick streamside vegetation and ponds and pools in streams where it can hunt its underwater prey.

However, diversions, dropping water tables and dams have drastically affected more than 90 percent of Arizona streams and rivers.

Moreover, the snakes have struggled to survive the impact of non-native predators that gobble up the young snakes when they’re not much more than a wiggle and compete for food with the snakes that survive. That includes species like bass, but most especially it includes bullfrogs.

These voracious amphibians were introduced by the Arizona Game and Fish Department in a misbegotten effort to establish a bullfrog fishery, since frog legs are a delicacy in areas where the bullfrogs originated. Instead, the bullfrogs became the scourge of Arizona’s riparian areas — along with the also-introduced crayfish. The giant frogs can cross miles of open country to reach streams and ponds, so they have spread throughout Arizona. They will eat almost anything smaller than themselves and make a quick snack of baby garter snakes.

Biological surveys of riparian areas throughout Arizona found the Northern Mexican Garter Snakes had vanished from almost all of the streams in Arizona and New Mexico in which they’d once thrived. The snake was last recorded in New Mexico in 2002.

Currently, biologists believe the snake’s distribution in Arizona is limited to the upper and middle Verde River drainage, the middle and lower reaches of Tonto Creek and isolated ponds, stock tanks and riparian stretches in the San Rafael Valley. However, cited a loophole to reject the 2006 request for a listing.

The snake historically also lived in the Sierra Madre Occidental and Mexican Plateau in Mexico. Biologists said the snake’s populations had also declined dramatically in Mexico, but since the Mexican government hadn’t done any formal studies or rigorous population studies, the USFWS concluded it lacked the information to conclude the snake was also endangered in Mexico.

At that time, the USFWS had a strict interpretation of a phrase in the endangered species act that said a candidate species had to be endangered in “a significant portion of its range.” Since the federal agency concluded that Arizona and New Mexico alone didn’t qualify as a “significant portion” of the range, it declined to act without better studies on the status of the snake in Mexico.

However, subsequent court cases involving Desert Bald Eagles and other species prompted the USFWS to adopt a less restrictive definition of “significant” and some new information from Mexico filled in gaps in knowledge there.

In addition, new information documented continued declines in the U.S. to no more than 10 percent of the historic range in this country.

As a result, the USFWS concluded it should list the snake as endangered.

However, the government now lacks the money to determine where the snake still exists, what it needs to survive and which riparian areas that constitute “critical habitat.”

Therefore, despite the new information, the Northern Mexican Garter Snake will have to remain a “candidate” species — joining a growing line of other creatures in legal limbo.

The outgoing Bush Administration has added only one species to the endangered list in the past eight years — the polar bear.

A federal listing of the snake could have substantial effects, given the degraded condition of Arizona riparian areas and the competing demands for water. As it turns out, the snake once lived in most of the stream stretches that also serve as critical habitat for other endangered species, including an array of native fish and the desert nesting population of bald eagles.

A formal listing would require the federal government to designate certain streams and riparian areas as “critical habitat” for the snake’s survival and recovery. That could then affect further development and diversion of those streams. That would be a boon for people who like healthy streams, but a problem for people who want to divert the water to other uses.


Use the comment form below to begin a discussion about this content.

Requires free registration

Posting comments requires a free account and verification.