If you feel as if you’re being watched while walking at some of Rhode Island’s beaches and wildlife refuges, you’re not alone. The 40-foot radio telemetry towers constructed at Trustom Pond, Sachuest Point, Napatree Point and Block Island’s Southeast Light – each topped with six antennae to enable monitoring in every direction – have certainly raised their share of questions. Conspiracy theorists might assume that they are part of a covert government operation to keep track of the private lives of ordinary Rhode Islanders. But they’re not invading anyone’s privacy. Not unless you’re a bird.
The towers are part of a network that runs from the Canadian Maritimes to North Carolina that allows biologists to monitor the migratory movements of birds and bats through the region. The scientists in charge of the Rhode Island towers are especially interested in the offshore movements of several species of rare birds that live along our coast. The data they collect is sought by the federal Bureau of Ocean Energy Management to help it make appropriate siting decisions about future offshore energy facilities. But it’s also providing an intriguing look into the lives of our feathered friends.
Pamela Loring, who got her start in ornithology while studying at the University of Rhode Island and is now nearing completion of her doctorate at the University of Massachusetts, monitors the data collected from 20 towers located between Cape Cod and Long Island. In the last two years, she has captured more than 200 common and roseate terns, piping plovers and American oystercatchers and attached tiny “nanotags” to their backs with glue. The tags consist of a light-weight, digital transmitter that can be detected when the birds fly within about 20 miles of one of the 250 towers in the United States and Canada.
Most of the tagged plovers and oystercatchers have already arrived back in Rhode Island from their wintering grounds in the South, and the terns should start appearing any day now. So Loring is looking forward to collecting and analyzing another year of data. She has already learned some surprising details about the birds.
The terns, for instance, repeatedly move back and forth between Cape Cod, Buzzards Bay, Rhode Island and Long Island at all times of the day and night throughout the breeding season, something that previous aerial and boat-based surveys of bird populations could not reveal. Because Loring knows where each bird was tagged, she is discovering that birds from different nesting colonies move through the area in different ways.
She also was surprised to find many piping plovers depart on their southbound migration by flying far offshore rather than hugging the coast, as most biologists believed. One bird flew straight south from Cape Cod beginning at 7 p.m. and was detected by a tower in southern New Jersey eight hours later. The Rhode Island plovers took alternate routes – some started out heading south between Block Island and Montauk Point while others traversed Long Island Sound before turning south.
Loring and colleagues from URI and the U.S. Fish and Wildlife Service will capture additional birds this spring and summer to affix nanotags to them in hopes of collecting even more data in the future. So piping plovers seeking to keep their travel plans a secret should probably avoid suspicious scientists for the next couple of months.