Scientists hail golden age to trace bird migration with tech

TAKOMA PARK, Md. (AP) — A plump robin carrying a tiny metallic backpack with an antenna hops round a suburban yard in Takoma Park, then plucks a cicada from the bottom for a snack.

Ecologist Emily Williams watches via binoculars from behind a bush. On this clear spring day, she’s snooping on his courting life. “Now I’m watching to see whether he’s found a mate,” she mentioned, scrutinizing his interactions with one other robin in a close-by tree.

Once the bird strikes on at season’s finish, she’ll depend on the backpack to beam frequent location information to the Argos satellite tv for pc, then again to Williams’ laptop computer, to monitor it.

The purpose is to unravel why some American robins migrate lengthy distances, however others don’t. With extra exact details about nesting success and circumstances in breeding and wintering grounds, “we should be able to tell the relative roles of genetics versus the environment in shaping why birds migrate,” mentioned Williams, who is predicated at Georgetown University.

Putting beacons on birds will not be novel. But a brand new antenna on the International Space Station and receptors on the Argos satellite tv for pc, plus the shrinking measurement of monitoring chips and batteries, are permitting scientists to remotely monitor songbird actions in a lot better element than ever earlier than.

“We’re in a sort of golden age for bird research,” mentioned Adriaan Dokter, an ecologist at Cornell University who will not be instantly concerned with Williams’ examine. “It’s pretty amazing that we can satellite-track a robin with smaller and smaller chips. Ten years ago, that was unthinkable.”

The machine this robin is carrying may give exact places, inside about 30 toes (about 10 meters), as an alternative of round 125 miles (200 kilometers) for earlier generations of tags.

That means Williams can inform not solely whether or not the bird remains to be within the metropolis, however on which road or yard. Or whether or not it’s flown from the Washington, D.C., suburbs to land on the White House garden.

A second new tag, for less than the heaviest robins, consists of an accelerometer to present details about the bird’s actions; future variations may measure humidity and barometric stress. These Icarus tags work with a brand new antenna on the International Space Station.

That antenna was first turned on about two years in the past, “but there were some glitches with the power-supply and the computer, so we had to bring it down again with a Russian rocket, then transport it from Moscow to Germany to fix it,” mentioned Martin Wikelski, director of the Max Planck Institute of Animal Behavior, whose scientific team is honing the know-how. After “the standard troubleshooting for house science,” the antenna was turned back on this spring.

As researchers deploy precision tags, Wikelski envisions the development of “an ‘Internet of animals’ — a collection of sensors around the world giving us a better picture of the movement of life on the planet.”

The American robin is an iconic songbird in North America, its bright chirp a harbinger of spring. Yet its migratory habits remain a bit mysterious to scientists.

“It’s astounding how little we know about some of the most common songbirds,” said Ken Rosenberg, a conservation scientist at Cornell University. “We have a general idea of migration, a range map, but that’s really just a broad impression.”

An earlier study Williams worked on showed some robins are long-distance migrants — flying more than 2,780 miles (4,480 km) between their breeding area in Alaska and winter grounds in Texas — while others hop around a single backyard most of the year.

What factors drive some robins to migrate, while others don’t? Does it have to do with available food, temperature fluctuations or success in mating and rearing chicks?

Williams hopes more detailed data from satellite tags, combined with records of nesting success, will provide insights, and she’s working with partners who are tagging robins in Alaska, Indiana and Florida for a three-year study.

Scientists have previously put GPS-tracking devices on larger raptors, but the technology has only recently become small and light enough for some songbirds. Tracking devices must be less than 5% of the animal’s weight to avoid encumbering them.

In a Silver Spring, Maryland, yard, Williams has unfurled nylon nets between tall aluminum poles. When a robin flies into the net, she delicately untangles the bird. Then she holds it in a “bander’s grip” — with her forefinger and center finger loosely on both facet of the bird’s neck, and one other two fingers round its physique.

On a tarp, she measures the robin’s beak size, takes a toenail clipping and plucks a tail feather to gauge total well being.

Then she weighs the bird in a small cup on a scale. This one is about 80 grams, simply over the edge for carrying the penny-sized Argos satellite tv for pc tag.

Williams fashions a makeshift saddle with clear jewellery wire looped round every of the bird’s legs. She then tightens the wire so the tag sits firmly on the bird’s again.

When she opens her hand, the robin hops to the bottom, then takes a couple of steps underneath a pink azalea shrub earlier than flying off.

In addition to offering very exact places, the satellite tv for pc tags transmit information that may be downloaded from afar onto Williams’ laptop computer. The information on older tags couldn’t be retrieved until the identical bird was recaptured the next 12 months — a tough and unsure activity.

Wilkeski hopes the brand new know-how will assist scientists higher perceive threats birds and different creatures face from habitat loss, air pollution and local weather change.

“It is detective work to strive to work out why a inhabitants is declining,” mentioned Ben Freeman, a biologist on the Biodiversity Research Centre on the University of British Columbia. Better details about migration corridors “will help us look in the right places.”

A 2019 study co-written by Cornell’s Rosenberg confirmed that North America’s inhabitants of untamed birds declined by almost 30%, or three billion, since 1970.

He mentioned monitoring birds will assist clarify why: “Where in their annual cycles do migratory birds face the greatest threats? Is it exposure to pesticides in Mexico, the clearing of rainforests in Brazil, or is it what people are doing in their backyards here in the U.S.?”

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Follow Christina Larson on Twitter:@larsonchristina

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The Associated Press Health and Science Department receives help from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely accountable for all content material.

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