New research uncovers the wanderings of Magnificent Frigatebirds

11/12/2013 | 0

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Magnificent Frigatebird by S. Hunter Spenceley

In a terrific article in our December issue, writer and bird guide Mark Hedden describes efforts by scientists in Florida to study Magnificent Frigatebirds. The large, mostly black seabirds nest from Florida’s Dry Tortugas to Brazil and from the northern Gulf of California to the Galápagos, but until recently little had been known about their day-to-day or year-to-year movements.

“What we know about Magnificent Frigatebirds,” Hedden writes, “is largely the result of observations made at single locations, or from behavior witnessed by happenstance.”

One thing that is known is that about half of the frigatebird colonies in the Caribbean have been extirpated in recent decades. To learn more about the birds — and potentially develop a management plan to stem their decline — biologists from the U.S. Fish and Wildlife Service and the Avian Research and Conservation Institute (ARCI), a Gainesville-based nonprofit research organization that specializes in radio and satellite tracking Florida avifauna, have launched a frigatebird-tracking study.

Red dots plot the movements of an adult female Magnificent Frigatebird from the Florida Keys (upper right) to the Yucatán Peninsula (lower left) between October 2012 and August 2013. Credit: Avian Research and Conservation Institute, 2013

Red dots plot the movements of an adult female Magnificent Frigatebird from the Florida Keys (upper right) to the Yucatán Peninsula (lower left) between October 2012 and August 2013. Credit: Avian Research and Conservation Institute, 2013

In the last year or so, they have attached 20-gram solar-powered transmitters to seven birds. Orbiting satellites retrieve transmissions from the devices and redirect them to reception stations on land.

Each transmitter costs approximately $5,000, and retrieving the data costs about $1,200 per year per transmitter. Grants from the Fish and Wildlife Service, as well as additional money from the Florida Keys Audubon Society and the Hernando Audubon Society, made the research possible. (The National Park Service provided in-kind and collaborative support on the project.)

The work has produced fascinating insights into frigatebird movements. For example, the map above plots the movements of an adult female frigatebird between October 2012 and August 2013. The data collection will continue for several more years.

Learn more

See more maps of frigatebird movements and sign up to receive daily project updates.

Learn more about Avian Research and Conservation Institute’s tracking studies.

Listen to the sound of bills and calls recorded at a colony of 5,000 frigatebirds.