The osprey comeback continues on Boston’s North Shore, according to a report by Essex County Greenbelt.
Twenty-six pairs of osprey were spotted nesting in Essex County in 2013, the most since Greenbelt began building and repairing nesting platforms about seven years ago to help bring the coastal raptors back to the area, the organization reported.
Volunteers in Greenbelt’s osprey watch program reported six nesting pairs in Ipswich; four each in Essex, Rowley, and Salisbury; two each in Marblehead and Newbury; and one nesting pair in Salem, Danvers, Gloucester, and Newburyport.
“The osprey is one of those great iconic birds that really capture people’s imagination,” said Dave Rimmer, Greenbelt’s director of stewardship.
He has spearheaded efforts to increase the number of breeding ospreys in the area since 2007, and in 2013 he formalized an osprey program, which includes building and maintaining platforms where the birds can nest, and monitoring breeding pairs from afar — in one case, from a webcam at Cox Reservation in Essex.
Rimmer noted that because the raptors build their nests on manmade structures in the middle of marshes, they can be more easily observed than other breeds. “People really enjoy watching them and learning about them,” he said.
The North Shore findings will be shared with a national osprey watch program, and because breeding populations often reflect the overall health of an ecosystem, the tally also might drive future conservation efforts of Greenbelt, a land trust.
“The more information we have, the better decisions we’ll be able to make, and the better case we can make if we need to generate support for [conserving] a property,” Rimmer said.
The report, Status of Osprey Breeding Activity in Essex County Massachusetts 2013, is posted on the Greenbelt website at ecga.org. Taken from observations by staffers and 20 volunteers in 10 communities, the report states that there were more nests — 32 — than the 26 breeding pairs and suggests that some may have built multiple nests. It also counted 21 fledglings (young birds).
The count confirms Rimmer’s estimates, and though previous information was gathered less formally, the tally represents an increase from previous years. He said there were 18 breeding pairs in 2012, 14 in 2011, and 11 in 2010.
Last year, Greenbelt collaborated with Rob Bierregaard of the University of North Carolina Charlotte to study osprey migration by banding and tracking two fledgling birds by satellite.
One of those birds, named Whit (for the Whittemore saltmarsh in Gloucester, where it was banded), has migrated to Venezuela, Rimmer said. The signal for the other bird, named Peirce, (for Jack Peirce, a Greenbelt founder) was lost in Pennsylvania.David Rattigan may be reached at drattigan.globe