Natures wonders: another amazing bird migration (Introduction)

by David Turell , Friday, September 01, 2023, 18:00 (239 days ago) @ David Turell

Olive-sided flycatcher travels from Alaska to South America each year:

https://mail.google.com/mail/u/0/#inbox/FMfcgzGtwqQdxxPLwXLBlVwblmFsrRpq

"For an olive-sided flycatcher, migration can be a marathon. Some of the soot-colored songbirds travel more than 15,000 miles a year, winging their way from South America to Alaska and then back again. It’s a dizzyingly long journey for a bird that weighs just over an ounce.

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"To survive the long trip, the birds need safe places to rest and refuel. But the locations of these “little utopias” were a mystery, Dr. Hagelin said. So in 2013, she and her colleagues set out to unravel it by tracking the birds. They hoped that identifying the critical stopover sites might provide clues about why olive-sided flycatcher populations were declining and what might be needed to save them, including where experts should target their conservation efforts.

"The research proved to be more difficult than they had bargained for. Olive-sided flycatchers often breed in buggy bogs. They perch at the tops of trees. And they are elusive, sparse on the landscape and difficult to catch. “After the first year of struggling with this project, it became really, really clear why nobody in their right mind would want to try and study this bird,” Dr. Hagelin said.

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"When the birds flew south for the winter, the geolocator tags regularly recorded the light levels and the time, allowing the scientists to estimate each bird’s approximate latitude and longitude. In later years of the study, they transitioned to using GPS tags, which can provide more precise location data.

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"Over the course of the five-year study, the researchers managed to deploy 95 tags. They recovered 17 geolocator tags but just five GPS tags — and three of the GPS tags failed, providing no data at all for reasons the scientists still do not understand. “That was really devastating,” Dr. Hagelin said.

“'But all was not lost,” she added. The geolocator data pointed to 13 important stopover sites, from Washington to southern Peru, plus three main wintering areas in South America, the researchers reported in 2021. Tagging technology has improved, so scientists with an appetite for flycatcher catching could now focus on collecting more detailed data on those locations. “Am I the person to do it?” Dr. Hagelin said. “Maybe if I had the funding.”

Comment: another amazing yearly migration of an amazing distance. I wonder why so far when the Monarchs have a nice spot in the mountains of Mexico at one-third the distance. The flycatchers eat flying insects which are abundant in all warm climates so that is not an issue. They tend to nest in coniferous fir trees, again a non-issue. So why southern Peru? Better tasting insects? Like all known extended migratory routes, I think God may have guided them.