Discoveries

May 23, 2023

Prepare for Takeoff

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Scientists recently discovered when some species of migratory songbirds decide to take their long-haul flights, the Washington Post reported.

These types of birds typically fly during the night, probably in an effort to avoid predators and stay cool, while using daylight for foraging.

Still, the reason for their timing has eluded researchers for years.

In a new paper, a research team equipped 400 songbird species with radio-tracking devices. Their study focused on where migrations begin, instead of stopovers, in order to lower the effects of variables – such as food availability – that could affect birds’ flight decisions.

Data from the tracking devices showed that the birds had a much narrower migration takeoff window than expected: 90 percent of the birds would depart within 69 minutes of dusk.

“This is a really tight window, which suggests there is something important about this time of night,” said co-author Nathan Cooper. “And we argue, this consistent departure time early in the night is about maximizing night flight time.”

Cooper and his colleagues also conducted a separate study where they found that migratory songbirds are also good meteorologists. They noticed that four of the studied species picked their takeoff schedule based on changes in atmospheric pressure.

Their findings suggested the creatures would depart when atmospheric pressure had risen over the previous 24 hours – a sign that there would be fair weather in the days ahead.

Still, other factors could be at play in the birds’ timing, such as age, sex, and celestial cues, the authors noted.

This story originally appeared in the May 23, 2023 newsletter, Full Court Press.