Gila Monsters Face Multiple Threats From Warming, Notably Water During Shifting Monsoon Seasons, Prey Availability

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Gila monsters are shrouded in mystery. The venomous, desert-dwelling lizards spend most of their lives underground and out of sight, only coming up to the surface occasionally to hunt for food, bask in the sun or find a mate. These hefty reptiles that look like they’re covered with Halloween-colored beadwork are so introverted that scientists aren’t even certain how many of them exist across their range, which spans the American Southwest and northwestern Mexico. What is known is that their population is decreasing—the International Union for Conservation of Nature lists them as a “near-threatened” species due to challenges like human development and invasive species.

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Though there is scant research on how Gila monsters might fare in a warming world, a March study published in Ecology and Evolution suggests that their range in the Mojave Desert—considered their northernmost habitat—could shrink significantly under higher emissions scenarios. Some of the most pressing climate-related threats to the species include a shifting monsoon season and reduced availability of food, researchers note. It’s unclear how far these lizards will go to adapt to a new climate future, and scientists are divided on where to focus their efforts to help the species survive.

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Gila monsters are dependent on the summer monsoon season for hydration, he explained. Most projections suggest that under current climate models, the Southwestern monsoon season, which brings increased moisture and rainfall to the region, will start later in the summer, according to Climate.gov. This delay could cost Gila monsters, (Ed. - Arizona State biologist Dale) DeNardo said. Though they can reabsorb the water content of their urine, utilizing their bladder sort of like an internal canteen, this hydration reservoir can only carry monsters so far.

“The problem is that this canteen gives them about 80 days of buffer against a long drought,” DeNardo said. “So they can go 80 days before they get significantly dehydrated.” While that’s doable in current conditions, just a half-month delay of the monsoon season could push Gila monsters into dangerous territory, he said. “Even with this canteen they have, they’re not going to be able to tolerate this extended longer hot dry season,” DeNardo said. Gila monsters can survive for months without feeding by storing fat in their tails. Still, they need to eat a few large meals per year, with the feasts usually consisting of rodents, birds, insects, eggs and other reptiles. They paralyze their prey with a potent venom that scientists have used to develop drugs that can treat type 2 diabetes. But some experts are worried that climate change could significantly reduce their ability to find food. “Gilas are built to survive,” said Leland Pierce, state herpetologist (a reptile and amphibian specialist) at the New Mexico Department of Game and Fish. “But it’s all going to come down to how does changing climate impact their prey?”

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https://insideclimatenews.org/news/16092025/gila-monster-under-threat-southwest-desert/