What is it about?

Birds can fly for hours, or even days, without stopping when they migrate. To do this, they burn a lot of fat. But they also burn protein, but this typically comes from vital organs and muscles so we expect it to have negative consequences. We flew two species of migratory songbirds in a wind tunnel--a treadmill for flying birds--up to a record-breaking 28 hours of non-stop flapping flight to show that they do indeed burn fat consistently. But rather than a consistent amount or turning to protein only when they run out of fat, their protein breakdown is especially concentrated to the first few hours of flight. This opens up lots of questions about the purpose of burning protein and what is happening in those initial hours of flight.

Featured Image

Why is it important?

Migratory birds are among the animals that are most at risk for climate-related declines. Understanding how they use fuel in flight can help us recognize what it takes for them to complete their journeys and more accurately predict where and when they might be most vulnerable to negative effects of environmental changes. Since they’re well adapted to hours or days of non-stop, high-intensity exercise, we can also learn a lot from how they prepare to migrate and rapidly rebuild their bodies after these long-distance flights. Flying birds for a long time in the wind tunnel gives us an unprecedented, quantitative look into these endurance feats to understand the factors that may limit their flight duration.


This was truly a team effort. Flying birds overnight for up to 28 hours in a wind tunnel is a challenge, and it only works when you have a bunch of like-minded individuals who are willing to forgo sleep to push the limits of our understanding! While we still don't understand why these birds show this consistent, repeatable pattern of protein burn, we have many hypotheses and a whole lot of determined folks who are interested in figuring it out! And now, thanks to our star bird ("BLPW_YELLOW") we know that these longer flights can be done in a wind tunnel to give us a more accurate look at what's going on during their ultra-endurance journeys.

Dr. Cory Elowe
University of Massachusetts Amherst

Read the Original

This page is a summary of: Long-duration wind tunnel flights reveal exponential declines in protein catabolism over time in short- and long-distance migratory warblers, Proceedings of the National Academy of Sciences, April 2023, Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.2216016120.
You can read the full text:




The following have contributed to this page