Vermont
Loons Are Studied at Night
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.
 Another
Record Year for Endangered Loons in Vermont
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.
Endangered Loons Challenged by Lead and
Mercury Poisoning and Entanglement in Fishing Line
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.
For more information,
contact VINS loon biologist Eric Hanson at
802-472-6905 or NNHP coordinator Steve Parren at
802-241-3717. |
