Nongame and Natural Heritage Program
Department of Fish and Wildlife
Vermont Agency of Natural Resources
July 1999

In July and August, biologists will capture, band, and examine loons on several Vermont lakes in an effort to determine the loons' overall health. Biologists will take blood and feather samples that will be analyzed to determine levels of mercury and lead in the loons.

Mercury contamination of loons has caused increasing concern among biologists in recent years. Mercury levels in loons sampled in other New England states have so far been the highest ever recorded in the U.S. In Vermont last summer, loons and their eggs were tested for mercury on three ponds. Lead is a concern because loons die of lead poisoning after swallowing lead sinkers and jigs used for fishing.

Because loons are so elusive, a team of biologists will work late at night by boat, locating birds with bright lights and capturing them in large nets. Once their heads are covered, the birds calm down while being banded, weighed, sampled, and then released. More than 2,000 adults loons in the United States and Canada have been sampled without serious injury--a remarkable record.

The bright lights associated with this research procedure should not cause alarm for lakeshore residents. Signs will be posted at boat launch areas of the waterbodies where the research will be done.

The study is being conducted by biologists from the Vermont Institute of Natural Science (VINS), Vermont Department of Fish and Wildlife, BioDiversity Research Institute, U.S. Fish and Wildlife Service, and the U.S. Geological Survey's Biological Research Division.

For more information about this long-term research project, contact VINS loon biologist Eric Hanson at 802-472-6905. To exchange lead fishing sinkers for non-lead samples and receive an informational brochure about water birds and lead, contact the Vermont Agency of Natural Resources, Department of Fish and Wildlife's main or district offices. For a list of lead sinker exchange sites in the Northeast Kingdom of Vermont, call Mark Lorenzo of the National Wildlife Federation at 802-229-0650 or Ross Stevens at Brighton State Park.

Nongame and Natural Heritage Program
Department of Fish and Wildlife
Vermont Agency of Natural Resources
September-October 1999

Biologists report another record-breaking year of reproductive success for the common loon, a species considered endangered in Vermont since 1987. Of the 33 pairs that attempted to nest this summer, 25 hatched 41 eggs, with 36 chicks surviving through August. These represent the highest numbers of nests, eggs hatched, and chicks surviving through August since loon record keeping began in 1978.

An estimate of the total population of common loons is made annually on the third Saturday in July. This year's Vermont Loon Watch involved more than 240 volunteers who surveyed 150 lakes and ponds throughout the state for one hour. The official population estimates are based on the same 100 lakes surveyed over the past several years, and there were 112 adult loons, 5 subadults, and 35 chicks counted. Previous year's adult counts for comparison were 104 in 1998, 99 in 1997, and 79 in 1996. Although the number of nesting pairs, chicks produced, and total population of loons are increasing in Vermont, these numbers are not high enough for biologists to consider their population secure.

Harassment by people is another challenge these birds face. This year several cases were reported, resulting in the death of one breeding adult and one chick. People should report incidences of loon harassment to local game wardens via the State Police dispatcher.Management efforts include monitoring and educational efforts by 50 volunteers, stabilization of water levels by hydroelectric companies, and enhancement of nesting habitat with artificial nesting platforms. These are in addition to the efforts of many cooperating organizations and agencies which have helped loons continue their recent trend of nesting success. Three lakes saw successful breeding pairs for the first time this summer, Bourn Pond in Sunderland, Bald Hill Pond in Westmore, and Nichols Pond in Woodbury. This year, 13 of the 33 breeding pairs nested on artificial platforms.

Financial support for this project comes from the Nongame Wildlife Fund, administered by the Nongame and Natural Heritage Program (NNHP) in the Vermont Department of Fish and Wildlife. The Vermont Institute of Natural Science's (VINS) loon biologist Eric Hanson coordinated the project again this year. Additional funding is sought to expand the Vermont Loon Recovery Project, a joint effort of VINS and the Vermont Department of Fish and Wildlife. Donations, designated for loons, may be sent to VINS in Woodstock. Donations for nongame species, including the loon, may be made to the Nongame Wildlife Fund and sent to the Fish and Wildlife office in Waterbury. For more information, contact Eric Hanson at 802-472-6905 or NNHP outreach coordinator Linda Henzel at 802-241-3716.

Nongame and Natural Heritage Program
Department of Fish and Wildlife
Vermont Agency of Natural Resources
September-October 1999

Monitoring and research efforts focused on the common loon over the past decade have revealed that these Vermont endangered birds face a number of challenges.

Since 1989, an alarming number of Vermont loons have died from poisoning by lead sinkers. Since 1996, eight loons in Vermont have been reported entangled in fishing line, with death confirmed in one case. In the past two years, researchers have begun to document the potential threat to Vermont loons from mercury poisoning.Eight of 15 adult loons in Vermont that were evaluated for cause of death between 1989 and 1998 died of lead poisoning from ingesting lead sinkers. Loons and other waterbirds swallow small stones and grit to aid digestion. Many lead sinkers and jigs are similar in appearance to these stones. In other instances, loons have ingested lead by taking baited lines. Once a lead sinker or jig reaches the loon's stomach, acids released there and the grinding action facilitate the absorption of lead into their bloodstream, with death resulting, often in about a week.

According to Nongame and Natural Heritage Program coordinator Steve Parren, "these numbers may not seem significant at first glance, but when a species produces just 36 offspring in one year, as the loon did this year in Vermont, the loss of even one of these birds is significant." Loons are ancient birds that have come to symbolize grace, beauty, and wildness, and their behaviors and sounds providing an enriching experience for people. Loons are not the only birds affected by the use of lead sinkers and jigs, but the effects of these materials on loons have been well documented throughout the northeastern United States.

A lead sinker exchange program and education campaign about the dangers of lead sinkers and jigs was launched this year in Vermont. Cooperators include the National Wildlife Federation, Silvio Conte National Wildlife Refuge, Vermont Department of Fish and Wildlife, Vermont Institute of Natural Science (VINS), Vermont Audubon, and the U.S. Fish and Wildlife Service (USFWS). Contact any of those organizations for written materials and to exchange lead sinkers for non-lead alternatives. Anglers are asked to remove all spent fishing line from Vermont waters and shorelines and encourage their sporting goods stores to stock non-lead fishing tackle.

Last year was the first year in which mercury levels in live loons were studied in Vermont. The three ponds studied in 1998 revealed low levels of mercury in the loons captured there. Biologists also collected abandoned eggs in 1997 and 1998 and analyzed their mercury levels. The eggs in four of the 15 waterbodies surveyed contained mercury levels in the high risk category. Loon biologist Eric Hanson, this year's coordinator of the Vermont Loon Recovery Project, explains that "studies by the BioDiversity Research Institute have found that eggs in the high risk category are less viable, with lower productivity by the birds a likely result."

The mercury research is part of a study which is assessing contaminants in the common loon population throughout North America. Partners with the BioDiversity Research Institute in this research include USFWS, the U.S. Geological Survey, VINS, and the Vermont Department of Fish and Wildlife. The effort will continue in future years on selected Vermont lakes.

The common loon was listed as an endangered species in Vermont in 1987. The population has been increasing in the state for the past several years. However, their numbers are not yet sufficient for biologists to recommend a change in their endangered status. Financial support for this project comes from the Nongame Wildlife Fund, administered by the Nongame and Natural Heritage Program (NNHP) in the Vermont Department of Fish and Wildlife. The Vermont Institute of Natural Science's (VINS) loon biologist Eric Hanson coordinated the project again this year. Additional funding is sought to expand the Vermont Loon Recovery Project, a joint effort of VINS and the Vermont Department of Fish and Wildlife. Donations, designated for loons, may be sent to VINS in Woodstock. Donations for nongame species, including the loon, can be sent to the Nongame Wildlife Fund at the Fish and Wildlife office in Waterbury.