(CN) – It’s a good bet the year after a rainy season someone is going to get bit by a rattlesnake in California, according to a study of 20 years of snakebite data released Thursday.
Rain and drought play a big role in the mating habits of rodents and snakes, which in turn means humans will get bit more often, the study’s authors say.
According to the study published in Clinical Toxicology, California’s rattlesnakes go on a feeding frenzy after the rodent population goes on a mating frenzy due to more rain and vegetation for the critters to eat.
Grant Lipman, an emergency medicine physician at Stanford Medicine and one of the authors of the study, offered an explanation: “More food, more snakes, more snakebites. But that’s just our theory.”
Researchers expected to find that rattlesnakes would become desperate during a drought and bite more humans while searching for food, but that wasn’t the case.
The researchers reviewed every phone call made to the California Poison Control System from 1997 to 2017. Of the calls received, 5,365 involved snakebites – all from rattlesnakes.
Five deaths were reported over the 20-year period and most occurred during the spring or summer in counties with shrub or scrub growth. Mariposa County, near Yosemite National Park, had the highest rate with 96 bites per 1 million people, according to the study.
Following a drought, snakebite reports decreased by 10 percent – and the reverse was true after a rainy season. An extreme example of this theory played out during a two drought periods in California, between 2002-2005 and 2007-2010. California’s worst drought period, from 2015-2016, saw the lowest point in reported snakebites, the researchers found.
Lipman says snakebites can be avoided and humans should give rattlesnakes a wide berth when they encounter one in the wild. He advised stomping on the ground to scare them away.
Brian Todd, an associate professor of fish, wildlife and conservation biology at University of California, Davis – who was not part of the study and had not read the research – said it’s not a stretch to say there is a direct link between weather and rattlesnake populations.
Rattlesnakes only mate once a year, Todd said, which explains the delay in the population boom after the rainy season and the increase in reported bites.
According to Todd, there is also a noted difference between legitimate snakebites and ones that shouldn’t have happened in the first place.
“In ERs they have a joke: What’s the most common expression you hear before a snakebite? Hold my beer. Or watch this,” Todd said in an interview, noting snakebites can usually be avoided except the person took it upon themselves to try and kill the snake.
According to Lipman’s study, snakebite data from 1997-2007 shows men were most commonly bitten. They were typically in a back yard and had an average age of 37.
Todd saidthe best treatment after a bite are a person’s car keys.
“Drive to a hospital. Don’t try to suck the poison out,” said Todd. “Respect the snakes you find. Leave them alone.”