Primal, elemental, and evocative of the wild recesses of the human spirit, the “common” loon is among our most beloved birds. Its rapacious ancestors swam with dinosaurs and snared sizeable fish in toothed bills. Recent genetic sleuthing has revealed that loons may be close relatives of penguins.
These strikingly beautiful creatures have bones denser than those of other flying birds, enabling them to dive deeply underwater. Avian 747’s, their size and weight requires them to flap and pad across the water’s surface for up to a quarter of a mile before liftoff. If they land on small ponds, they simply can¹t become airborne again.
After overwintering where there is open water for fishing, loons return to breed in New Hampshire and Vermont during April and May. En route, they fly up to 75 miles per hour. Loons almost always come back to the same nesting ground each year. Once they return, they usually pair with the same partner to construct a nest of soggy plants and moss 2 feet across and 6 inches above the water level. A loon’s feet are so far back that it must push along on land: nests must be close to the water’s edge.
Two eggs, usually, are laid in the nest. In about 27 days, chicks hatch and parents encourage them into the water with a special song. Hungry chicks use a shrill begging call. Parents sing a duet to defend breeding grounds. The most famous loon song is the male¹s haunting, yodel-like territorial defense.
Loons nest throughout New Hampshire but are most abundant in the north country and Lakes Region. They aren’t found in the higher White Mountains and are not common in the south. The Northeastern Kingdom is home to roughly 85 percent of Vermont’s breeding loons. A smattering of nests is also found amid the lakes and reservoirs of the central and southern Green Mountains.
A few loon pairs breed in the Connecticut River valley, including Grafton Pond, Goose Pond, Smith Pond, and Lake Tarleton in New Hampshire and Symes Pond and Woodward Reservoir in Vermont. Loons occur on Lake Fairlee and Lake Morey, and on Miller Pond, but have not been seen nesting there. Vermont overall has less suitable breeding habitat than New Hampshire.
Our local loons were once in dire straits. Eric Hanson, biologist for the Vermont Loon Recovery Program of the Vermont Institute of Natural Science, says that during 1983, 7 nesting pairs produced 9 surviving chicks. According to Harry Vogel, executive director of the Loon Preservation Committee, back in 1976, there were 74 pairs of nesting loons statewide. A mere 48 chicks hatched that year, and 44 of them survived into autumn.
Extensive research and management have helped loon populations to grow steadily. In 2005, there were 204 breeding pairs in New Hampshire and 112 surviving chicks. In Vermont, 47 breeding pairs raised 57 young into the migration season. Preservation efforts include monitoring and protecting prime breeding grounds, creating artificial nest platforms, stabilizing water levels, educating the public, and posting warning signs in breeding areas.
But people still disturb loons in nesting and feeding grounds. Construction destroys habitat. Water level changes either strand or flood nests. Waves from passing boats wash eggs away. Loons are sometimes shot, run over by boats, or tangled in fishing line.
Loons are the proverbial canaries in the coal mine – excellent indicators of environmental problems because they return to the same environments each year. They can be banded and monitored through time to observe changes in behavior and reproductive success. They are especially affected by one particular environmental contaminant: mercury.
Mercury comes from airborne pollution created by coal-burning power plants, combustion engines, and incinerators. Half of all mercury contamination is from local and regional sources. Mercury causes abnormal behavior in loon adults, which are unable to establish and defend nesting territories. The survival of loon chicks is down by 40 percent in some lakes where mercury levels are high. Eggs can be killed by concentrations as low as 1.3 parts per million.
An easier problem to tackle is lead poisoning in loons. On average, poisoning from lead fishing tackle kills half of all loons found dead each year. It is now illegal in Vermont and New Hampshire to sell small lead sinkers. New Hampshire also prohibits the sale of small lead jigs and currently bans the use of both as well. A Vermont ban on using small lead sinkers begins in 2007.
To help preserve these magnificent birds, call the Loon Preservation Committee at (603) 476-5666 or the Loon Recovery Project at (802) 586-8064. Encourage friends and family to stop using lead sinkers and jigs and ask local stores to carry only non-lead tackle. It is rare that such simple actions can help to save a species in peril.