Chris Martin, (603) 224-9909
Mike Marchand, (603) 271-3016
Liza Poinier, (603) 271-3211
October 31, 2008
N.H.'S Peregrine Falcons Have Successful Breeding Season, but a New Concern Emerges for Raptor Health
CONCORD, N.H. -- New Hampshire's peregrine falcon population continued its gradual climb toward full recovery in the state in 2008. Breeding pairs used natural cliffs, an urban building, and an Interstate highway bridge as places to raise a record-high 27 young this year. Recognizing the gradual improvement in the status of peregrines, the New Hampshire Fish and Game Department recently downlisted the fast-flying raptor from the endangered to the threatened category on the state's List of Threatened and Endangered Wildlife. Yet celebration of their recovery has been tempered by new concerns about exposure to flame-retardant chemicals called PBDEs.
Overall, the peregrine breeding population in New Hampshire has increased by 50% over the past decade; in 1998 there were just 12 occupied territories found. "The numbers we track for peregrines are trending up, but only slowly," said Chris Martin, a New Hampshire Audubon raptor specialist who coordinates the state's peregrine monitoring efforts. Biologists and volunteer observers affiliated with N.H. Audubon confirmed 18 occupied peregrine falcon breeding territories in the state in 2008, matching a benchmark high set in the previous year. Seventeen of the 18 territories hosted falcon pairs, with one additional site supporting only a single female bird.
As the number of breeding pairs has increased, so has the total number of young being produced annually. Over the most recent 10-year period, from 1999 to 2008, peregrines nesting across the state have produced an average total of 22.5 young per year. From 1989-1998, pairs produced an average total of 11.2 young per year statewide. In the 1980s, they produced fewer than three young per year on average. A grand total of 360 chicks have fledged from New Hampshire peregrine nests since they first began breeding in the state again about 27 years ago. Juvenile peregrines are considered fledged at six weeks of age, when they first begin to fly to and from the nest.
Statewide in 2008, 27 young peregrines reached fledging age, equaling a record high set in 2002, but which had not been matched again until this year. Three out of 16 egg-laying pairs failed to hatch their eggs this year, including one pair in Franconia Notch State Park that unsuccessfully incubated eggs for an astonishing 12 consecutive weeks, far beyond the typical five-week interval. Biologists were pleasantly surprised to find that every one of the record-high 13 pairs that hatched eggs eventually managed to fledge one or more chicks. "Seeing 100% success after hatch is unusual, but it certainly results in more young fledged," said Martin.
Management of the state's recovering peregrine falcon population is carried out by N. H. Audubon, working under contract with the New Hampshire Fish and Game Department's Nongame and Endangered Wildlife Program. Management actions include tracking recreational use at cliffs, posting temporary closures on rock climbing routes when needed, and providing technical advice to natural resource agencies and to the public. N. H. Audubon also recruits, trains and deploys volunteer observers to document peregrine distribution and productivity, and to band young; these activities are currently supported by private donations.
Martin and a team of rock climbing volunteers accessed nine peregrine nests in the state in 2008, examining and banding 16 nestlings at seven productive sites and recovering nine unhatched eggs from five nests. He estimates that roughly 30% of New Hampshire's breeding adult peregrines currently wear color-coded leg-bands. Some highlights among peregrine band recoveries in 2008 include a 13-year-old male raised in Dixville Notch and breeding in Franconia Notch, an 11-year-old male from Stark that has been confirmed breeding near Orford for 11 consecutive years, and two more locally raised birds found breeding on the Logan Airport control tower and on a campus building at the University of Massachusetts-Amherst.
The recovered eggs will be added to a growing regional data set being used to study the impact of contaminants on New England peregrines. Similar egg-collection efforts over past years are now providing important information about potentially harmful contaminants in the region's wildlife. For example, flame-retardant chemicals, called polybrominated diphenyl ethers or PBDEs, are commonly added to many consumer products, but PBDEs gradually escape into the environment and contaminate air, water, soil, wildlife and humans.
Sobering results from one recent contaminant study have just been published in the technical journal Environmental Science and Technology. In this study, titled Polybrominated Diphenyl Ethers in Peregrine Falcon (Falco peregrinus) Eggs from the Northeastern U.S., scientists from Virginia's College of William and Mary report unusually high levels of these PBDEs in 114 non-viable peregrine falcon eggs recovered from 35 nests in six New England states from 1996 to 2006. Slightly over half of the 114 eggs analyzed for the study came from New Hampshire peregrine nests. Two New Hampshire eggs exhibited "extremely high levels" of total PBDEs, concentrations that "rival the highest PBDE burdens reported in wildlife to date," according to the paper, authored by researcher Da Chen and others.
One of the paper's local co-authors is Michael Amaral, an endangered species specialist for the U.S. Fish and Wildlife Service's New England Field Office based in Concord. Since 1990, Amaral and colleagues from several New England wildlife agencies and conservation groups, including those at N. H. Fish and Game and N. H. Audubon, have been monitoring falcon productivity, banding young, and collecting unhatched eggs.
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 is the guardian of the state's marine, fish and wildlife resources and their habitats. Its Nongame and Endangered Wildlife Program works to protect over 400 species of mammals, birds, reptiles, and amphibians not hunted fished or trapped, as well as thousands of insects and other invertebrates. The program works in cooperation with other New Hampshire wildlife agencies and organizations to develop and implement effective conservation strategies to protect and enhance this diverse group of wildlife. Visit www.wildlife.state.nh.us/Wildlife/nongame_and_endangered_wildlife.htm.