Humming birds suffer if they move uphill to escape the warming climate

Enlarge (credit: Dan Ripplinger / 500px)

As the Earth’s climate warms, some animals may seek a reprieve from the heat in colder, northern climates or higher altitudes. For some species, these cooler locales may provide greener—so to speak—pastures than their current homes as annual average temperatures continue to increase.

For the diminutive Anna’s hummingbird—which calls North America’s West Coast from California to Vancouver, British Columbia, home—this might not be an option. According to research published Thursday in the Journal of Experimental Biology, a move to chillier and higher altitudes would achieve only two things: cause them to struggle to hover as their metabolic rate drops and sleep most of the day.

“As you get upslope, it’s colder, and also there’s less oxygen available. You can think of this like Everest; people have to go up to basecamp and bring extra oxygen and get used to it up there,” Austin Spence, one of the paper’s authors and a post-doctoral researcher at the University of California Davis’ Department of Wildlife, Fish, and Conservation Biology, told Ars.