To survive this week’s historic heat wave, much of the Bay Area’s wildlife is finding relief in deep burrows, damp mud or dense underbrush.
But baby tree squirrels, unable to dig or climb, are tumbling from tall trees — landing in a big hot mess.
Calling it a “squirrel-palooza,” Bay Area wildlife rescue groups report a surge of distressed animals and are mobilizing teams to rescue the rodents with ice packs, fluids, medications and special diets.
“They’re literally jumping from their nests to escape the heat,” said Buffy Martin Tarbox of the Peninsula Humane Society, which is treating 101 squirrels. Dehydrated and sometimes injured, the youngsters “don’t have the climbing skills to get back up.”
The Wildlife Center of Silicon Valley is caring for 188 tree squirrels, with more expected, said executive director Laura Hawkins. Of those, 138 are all blanketed in small cages that are stacked on shelves, and 50 are getting care at volunteers’ homes. At one point, 14 squirrels arrived in one hour.
“Everyone here is doing squirrel feedings,” said Hawkins. To ease the workload, the center is calling in extra volunteers to rotate through four-hour shifts.
At San Rafael’s WildCare, which is also seeing a surge in demand, “all of the little ones we’ve admitted this week have come in with symptoms of hyperthermia,” said Alison Hermance, director of communications. San Francisco’s Yggdrasil Urban Wildlife Rescue normally receives one to three baby squirrels a week; now, it’s getting four to seven every day.
Animals with heat-related issues need immediate care and constant monitoring, said Hermance.
“As with humans, wildlife patients need to be cooled down — but you can’t cool them down too quickly or you risk brain and other organ damage and death,” she said. Seizures are another risk, she added.
The baby squirrels are so small that they can’t get the usual emergency intravenous fluids. Instead, they must be rehydrated with fluids injected under the skin in the scruff of their neck. Each one is fed by syringe filled with special formula. To tell siblings apart, they may wear a colorful dab of nail polish on an ear.
Other animals are also feeling the heat, with centers reporting an increase in needy felines, skunks, opossum, fawns, some songbirds and cavity-nesting birds such as woodpeckers.
“We’ve seen definitely an uptick in bobcats,” said Ashley Quick, executive director of Wildlife Education and Rehabilitation Center in Morgan Hill. The center usually sees one or two but now is treating four, including a youngster found by hikers on a trail in Carmel.
On Wednesday, Walnut Creek’s Lindsay Wildlife Experience received a golden eagle that was severely dehydrated.
Heat affects wildlife in different ways, depending on a species’ exposure, physiology and behavior, said Jonathon Stillman, professor of biology at San Jose State University and an adjunct professor of integrative biology at UC Berkeley.
Reptiles, which are heat-adapted, aren’t stressed by our heat wave. They need much less water than mammals, birds, amphibians, fish or aquatic animals, said Stillman.
Fish are hard-hit by heat spikes, if water is no longer cool and oxygenated. If possible, they’ll seek deeper pools to get through a crisis, said Joe Sullivan, Fisheries Program Manager at the East Bay Regional Park District.
Mammals such as dogs, bears and adult squirrels do “splooting” — flattening themselves onto cool ground to reduce body heat. And mammals can sweat or pant to cool off, said Stillman. “But if we’re dehydrated, we can’t do that,” he said.
When hot and thirsty, wildlife will wander much farther for a drink — into our yards to drink from birdbaths or rummage in irrigated gardens. Deer are more likely to venture onto the edges of roads to eat moist plants in roadside ditches, risking car collision. Their carcasses attract scavengers, who are also in harm’s way.
Baby squirrels, without have a water source in their nests, dehydrate easily. Their nests quickly warm because they’re crowded with siblings and insulated with leaves, bark, palm fronds and other material, said Ashley Kinney, hospital manager for Wildlife Center of Silicon Valley.
Restless and fidgety, “sometimes they’ll move around to find a cooler spot and, unfortunately, they will fall out of the nest,” she said.
If our heat wave had arrived earlier in the season, the centers say they would have been flooded with an influx of baby birds, not squirrels. Last year’s extreme heat in the Northwest in late July inundated wildlife rescuers with young raptors that had jumped from their nests to try to escape deadly temperatures.
Of the stressed squirrels, very few are native Californians. They’re almost all Eastern Gray Squirrels, released here in the 1900s from the wetter and cooler East Coast. Abundant in our parks and yards, the species is fecund, with two litters a year — but a late-summer heat wave can put that second litter in peril.
Our native Western Gray Squirrel fares better in a late summer heat wave. It only has one litter, in the spring, and by now all of its offspring have left home.
There is growing evidence that heat waves may benefit other native species.
While invasive bullfrogs need water all year long, our native frogs can simply find small deep burrows and estivate — a form of summertime hibernation. Hot dry spells could limit the spread of the invasive Argentine ant, because it needs moisture, said Bay Area entomologist Merav Vonshak.
“Life is dicey,” said Stuart Weiss, chief scientist at Menlo Park’s Creekside Center for Earth Observation. “And we just rolled ‘snake eyes.’ It’s never been this hot before.”
“Every species is just doing its thing, and then you get an event like this,” he said. “Some will be in the wrong place at the wrong time.”
If you find a baby squirrel:
- Call a wildlife rescue center and ask for advice.
- If you pick it up, use a towel or cloth.
- Make it comfortable in a cool, dark and well-ventilated box
- Do not give it food or water. Ice water can induce shock. Food can cause aspiration injury.