Glossy snakes in El Monte Valley a rare surprise for USGS scientists
The recent sand mining project in El Monte Valley has left many locals outraged with the disturbance it will cause in the area.
The project will take a total of 19 years and the mining will begin by the fourth year. Eighteen million tons of cement resources will be spread over 189 of the 530 acres in the valley according to sandiegocounty.gov. The demand for sand in the county is high, three million tons a year is imported from other counties.
Jonathon Q. Richmond of the United States Geological Survey conducted the study: Rare alluvial sands of El Monte Valley, California support high herpetofaunal species richness and diversity of reptiles and amphibians, despite severe habitat disturbance.
The main objectives of the study are to find out if the California glossy snake still exists in El Monte Valley and to measure the species richness and diversity of the reptiles and amphibians inhabiting the materials left by river valleys within the El Monte Valley.
Richmond and his partner Matt split the project into five sections along where the El Monte Nature Preserve plans to sand mine in the valley. The reason they put it into five sections was to look at the differences in diversity across the valley. Each section has four, 500m fencing that traversed the valley and five cover board displays to trap the snakes. They also drove around the areas looking for different species in the valley.
The study lasted for 12 months and consisted of 48 days of trapping and 24 nights of walking approximately 75 miles and driving over 460 miles searching for reptiles and amphibians on the roads. They reported 27 native reptile and amphibian species found. Ten of them were on the list as species of special concern by the state of California. El Monte Valley is ranked ninth in species richness compared to 23 other USGS study sites.
“USGS over the past 21 years have been studying snakes at 23 different sites and 3,700 were snake species and they only caught one glossy snake yet we caught 20 in one year at El Monte Valley so that was shocking to us,” said Richmond.
In the study, Richmond found out that the glossy snakes were the second most abundant snake species in the valley, rattlesnakes being the first. This is important because they are considered top predators. Catching 20 unique glossy snake species, 23 in total, three were recaptured. They would take a sample of tissue from each of the snakes to keep track of any that would be recaptured.
“I was going to be stoked if we caught even just one,” he said.
They did not only find adult glossy snakes but also baby ones, so the snakes are reproducing in the valley.
“We are confident that this is a long term self sustained population,” he said.
The glossy snakes were found in four out of the five sections they divided the valley into. Anywhere in the EMV, with loose soil, they found a glossy snake.
In the different sections they found out in section one it had the highest richness in species with snakes, frogs, lizards and more. Section two and five were substantially lower due to those areas being the most disturbed.
Snakes in the experiment was the most captured species. He had 1,208 captures in total and 499 was captured using the cover board.
If you have not seen the El Monte Valley, it is a dry desert backcountry with an ecosystem that changes with the environmental conditions full of wildlife and fauna that depend on it. The current drought has effects that have taken a toll on the reptiles and amphibians that live there.
“We are at the end of a five year drought, and it can have a lot of effects and if we have a heavy rain winter and did this study again next year the results may be different,” said Richmond.
Within this short amount of time of sampling they found that EMV has a species count that ranks them ahead of many conserved lands in San Diego County.
“It took lot of work to do this but the payoff is big,” he said.