Invasive Snake Species Spreads Along Colorado River In Yuma

By Maya Springhawk Robnett
Published: Monday, December 19, 2016 - 9:20am
Updated: Thursday, January 19, 2017 - 4:24pm

(Photo by Maya Springhawk Robnett - KAWC)
Arizona Game and Fish Wildlife Manager Richard Meyers at Mittry Lake in Yuma, Arizona.
(Photo by Maya Springhawk Robnett - KAWC)
Arizona Game and Fish Wildlife Manager Richard Meyers searches for the Southern Banded Water Snake at Mittry Lake in Yuma, Arizona.
(Photo by Maya Springhawk Robnett - KAWC)
Mittry Lake in Yuma, Arizona.

An invasive snake has been found in Yuma waters. Officials are concerned because the snakes could pose a threat to local species and alter the Colorado River ecosystem.

“So where we’re heading right now is north of Yuma on Laguna Dam Road. We’re going to a lake called Mittry Lake," said Richard Meyers, an Arizona Game and Fish wildlife manager.

Meyers is investigating the arrival of the Southern Banded Water Snake at Mittry Lake and other Colorado River waters in the Yuma area.

On a humid Friday afternoon, Meyers, drives to the lake where the snakes have been spotted most frequently.

The invasive snake can grow up to 3 feet long. It sports thick bands of black and faint bands of orange. But you’re not likely to see one. As Meyers stands in a thick of cattail reeds, he said they like to hide.

“Sometimes if they’re going after an amphibian or frog or something, sometimes they’ll be on the edge of the water," Meyers said. "So, they probably hunt at night when these things are out doing their thing, so they’re probably skirting the shoreline, maybe at dusk. But during the day, they’re kind of like any animal. They’re getting back in refuge a little bit.”

The snakes like Mittry Lake because, with cattails and stagnant water, it is similar to the Florida swamps where the snakes are native. The animals are also drawn to the area due to the abundance of invertebrates, amphibians and fish.

They are not venomous, but Arizona Game and Fish is concerned about the snake’s impact on other species. They compete with and could potentially wipe out native species, such as the protected Giant Garter snake.

Sitting in his truck, Meyers explained that the snakes are already a problem in California, but he’s not sure how they got into this area.

“However it came in, whatever means it came in as, if it was somebody’s pet—it wasn’t just a pet, it was probably more than one," Meyers said. "So it would take two, obviously, to successfully breed, which they have done. We have over twenty now collected, so obviously there was more than the initial one that was reported.”

Arizona Game and Fish is monitoring the snakes and their spread.

“We probably have thousands at this point, based on how many we were able to collect,” said Lin Piest, the Terrestrial Wildlife Biologist for the Yuma office.

Piest, who has been with the department for 31 years, said the snakes might have started with just two, but they’ve quickly reproduced. He said another concern is how far the animals have spread geographically.

“We’ve pretty well documented where they occur around Yuma, like around the Mittry Lake area. Any sightings from Mittry Lake, I guess we’re not too concerned with but we’re still trying to document how far it’s spread up and down the river.”

That’s something a lot of experts worry about.

Robert Reed is the Branch Chief for Invasive Species Science at the Fort Collins Center of the U.S. Geological Survey. Reed traveled from his office in Colorado to the Yuma area for a 10-week study of the snakes. He said he wants to know about the potential impact they could have on the Colorado River ecosystem.

“I think it’s likely that they will spread," Reed said. "I think the spread will be fairly slow to the north because the Colorado becomes channelized and doesn’t have as much good habitat. I think that’ll slow them, but it won’t stop them.”

How far the snakes may spread south is another issue.

“I am concerned about their spread south in Mexico and then into the Colorado River Delta. I think that they’re probably in the Lower Colorado River to stay unless we develop some sort of a technological silver bullet for controlling that species," Reed said. "Thus far, those silver bullets have proved to be elusive for pretty much all invasive snakes.”

To try to slow the spread of the Southern Banded Water Snake, Game and Fish intends to conduct local trapping efforts in high conservation areas.

Officials encourage local residents to report any sightings.

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