Energy-saving strategy helps hummingbirds fuel their long migrations

[Judi Lynn]

Ruby-throated hummingbirds redeploy an energy-saving strategy they use to survive overnight without food to build energy stores for migration
Date:
December 14, 2021

Ruby-throated hummingbirds use the same energy-conserving strategy to survive overnight fasts and build the fat stores they need to fuel long migrations, shows a study published in eLife.

The findings help prove a long-held suspicion among scientists who study hummingbirds. They also provide new insights on the rules the birds use to determine whether to conserve energy or stockpile fat.

Tiny ruby-throated hummingbirds constantly eat sugary nectar to fuel the rapid wing movements that allow them to hover. To conserve energy during their overnight fasts, the birds can shift into an energy-saving mode called torpor by lowering their body temperature and slowing their metabolism up to 95%.

"We wanted to know if hummingbirds use this same energy-saving mechanism to more quickly build the fat stores they'll use to power their 5,000-kilometre migrations between their North American breeding grounds and Central American winter homes," says first author Erich Eberts, a PhD student at the Welch Lab, University of Toronto Scarborough, Ontario, Canada.

More:
https://www.sciencedaily.com/releases/2021/12/211214150204.htm

[Walleye]

1. Here's one of my juvenile males getting fat, getting rubies on his throat his past September

[Judi Lynn]

2. Precious tiny being! Wow. Have never seen a photo of a juvenile.

It must be wonderful being able to see them seasonally at close range. They are fascinating, unspeakably beautiful.

[Walleye]

3. Yes I am always delighted and amazed when they show up in the spring.