Chris Martin, NH Audubon, 603-224-9909
Michael Marchand, N.H. Fish and Game, 603-271-3016
Jane Vachon, N.H. Fish and Game, 603-271-3211
October 27, 2009
Rain Dampens Bald Eagle Breeding Success in 2009
CONCORD, N.H. – Following record breeding success in 2008, New Hampshire bald eagles experienced a far less productive breeding season in 2009. The total number of young eagles raised in nests in the state this summer was down 33% from last year. In spite of this one-year decline, 2009 was still the third best breeding year on record for bald eagles in the state.
“The number of young fledged can vary from year to year,” said Mike Marchand, a biologist with N.H. Fish and Game. “A number of factors can influence breeding success, including weather.” Marchand noted that although the number of young fledged during 2009 was lower than last year, the number of territorial pairs has been consistently increasing in New Hampshire, leading biologists to believe that the New Hampshire population will continue to grow.
The 19 territorial pairs documented in New Hampshire in 2009 represent an increase of more than 25% from the 15 eagle pairs found the state in 2008. “The growing number of breeding territories lays a foundation for more productive breeding seasons to come,” said Chris Martin, a raptor specialist with N.H. Audubon who coordinates monitoring of this state-listed threatened bird of prey. “Over time, more territories lead to more fledged young.”
Biologists and volunteer observers have documented a tripling in the number of bald eagle breeding territories in New Hampshire in the past decade, from just six pairs in 2000 to 19 pairs in 2009. “This is clear evidence of an expanding population,” Martin said.
The N.H. Fish and Game Department’s Nongame and Endangered Wildlife Program and N.H. Audubon’s Conservation Science staff work together to monitor and manage the Granite State’s recovering bald eagle population. With additional support and cooperation from land owners and from other state and federal natural resource agencies, N.H. Audubon recruits, trains, and deploys volunteer observers to document eagle distribution and productivity.
A growing number of bald eagles now call New Hampshire’s Lakes Region their home. Two new pairs were identified around Lake Winnipesaukee in 2009, raising the total number of pairs found throughout the Lakes Region to eight. Further west, on the Connecticut River in Orford, another new pair raised two young in their first try. In addition, after years of waiting, biologists believe that a pair has finally established a breeding territory on Great Bay, the state’s largest tidal estuary.
Although more bald eagle pairs were found in the state this year, rainy weather and other factors limited their reproductive success. A total of 16 bald eagle chicks reached fledging age in the state this summer, down one-third from the 24 young produced in 2008. Incubation behavior was confirmed at 11 nests in 2009, also down slightly from 2008 levels. Nine of the 11 incubating pairs fledged young. Juvenile bald eagles are considered fledged at about 11 weeks old, when they first begin to fly to and from the nest.
“Several eagle pairs built nests but did not incubate eggs, and two more pairs abandoned nests at about the time of hatch,” said Martin. Productivity was also limited by fact that none of the New Hampshire nests produced three fledglings in 2009, compared with three nests with trios in 2008.
Since 1988, when bald eagles first began nesting again in New Hampshire, a total of 123 young eagles have fledged from nests in the state. Nearly 60% of those (73 eaglets) have been raised in the last four years alone.
Martin estimates that over 50% of New Hampshire’s breeding adult eagles wear coded aluminum leg bands placed on them when they were nestlings. These bands provide biologists with opportunities to identify and track movements and longevity of individuals. Included among these banded eagles is New Hampshire’s oldest known eagle, a 17-year-old female hatched in captivity in Massachusetts, placed in a Quabbin Reservoir nest and raised by foster eagle parents. She has been breeding at Nubanusit Lake in Hancock for the past 11 consecutive years.
New Hampshire Audubon, a non-profit membership organization, is dedicated to the conservation of wildlife and habitat throughout the state. For more information about New Hampshire Audubon, visit www.nhaudubon.org.
The New Hampshire Fish and Game Department’s Nongame and Endangered Wildlife Program is the steward for species not hunted, fished or trapped. The program works in cooperation with other New Hampshire agencies and organizations to protect over 400 species of mammals, birds, reptiles, and amphibians, as well as thousands of insects and other invertebrates. For more information, visit www.wildnh.com/nongame.
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