Climate change is altering the way animals, insects and plants behave, and has cascading effects in delicately balanced ecosystems.

With longer springs, ticks are moving northward, bringing the chance of disease in animals and humans alike.

El Niño aside overall climate change is also changing the habits of some bears. Some American black bears not hibernating at all, due to both a warmer world and continuing food sources, mainly food provided unintentionally by humans.

According to a 2019 study by the National Audubon Society, two-thirds of North American birds are at risk of extinction due to climate change.

Other, smaller animals are also struggling to adapt.

“I’ve noticed in Connecticut, the spring peepers, the little frogs that come out, started a few weeks ago,” said Karesh. “It’s pretty early in the season when that’s happening now.”