Common Loon Fact Sheet
Common Loon
Gavia immer
New York Status: Special Concern
Federal Status: Not Listed
Description
Drawing by Jean Gawalt
Referred to as the "spirit of northern waters," the Common Loon is recognized as a symbol of unspoiled wilderness. In breeding plumage, this water bird is black-headed with a heavy, black, dagger-like bill, dark red eyes, a black collar, a white necklace, prominent white checks on the back, and white underparts. In non-breeding plumage, the body is essentially grayish above and whitish below with varying amounts of white showing on the side of the head. Dark traces of the collar are often visible. In the winter, the bill is lighter and of a grayish hue. Juveniles are similar to adults in winter plumage, but have more prominent barring across the back. A distinctive feature of the loon is its eerie, yodel-like call that can be heard on northern lakes where nesting occurs and on wintering areas in late winter and early spring.
Life History
Returning to the same breeding grounds year after year, Common Loons are believed to mate for life. Upon their return, the pair renews their bond with short displays, including synchronized swimming, head posturing and diving. The nest is built within a few feet of the water's edge by both the male and female. A clutch of two eggs is laid sometime between mid-May and June. The young hatch after an incubation period of 26-31 days and begin to swim almost at once. Within 24 hours, they are moved by the parents to a nursery area away from the nest. In 2-3 weeks, the young are able to make short dives and catch small fish. Fledging occurs in 11-13 weeks. Juveniles may spend several years in oceanic wintering areas before returning inland to breed. The loon's diet consists almost entirely of fish.
Distribution and Habitat
Common Loons breed across most of Alaska and Canada, south to Washington, Montana, Minnesota, Wisconsin, Michigan, New York and New England. In New York, Common Loons breed on the lakes of the Adirondack Mountains and in the St. Lawrence River region. Loons winter along the coast and on open lakes nearby.
While Common Loons are symbolic of quiet, secluded places, they also inhabit somewhat developed lakes. Larger lakes of 25 acres or more are generally preferred. The lake must be large enough to allow a clear takeoff over surrounding trees. The presence of both shallow and deep water is also important. Shallow water is used for foraging, nurseries and shelter, while deep water is necessary for adult diving and social interaction.
Status
Although historic information on Common Loons is incomplete, it is known that they were once much more abundant. It is likely that populations declined in the 1800's with European exploration and settlement. Common Loons prefer the quiet atmosphere of uninhabited lakes, but growing human populations create disturbances on these lakes as they are developed. Disturbances caused by paddling, camping, fishing, and boating on lakes can lower the loon's reproductive success. Anthropogenic impacts on loons and other wildlife arise from a variety of sources. Accidental ingestion of lead fishing tackle by loons leads to lead toxicity and death. Catastrophic events, such as oil spills and botulism outbreaks, have potential to significantly affect loon populations during migration or on their wintering grounds. In the Adirondacks, acidification of lakes and mercury contamination of water bodies is a problem. Acid rain lowers the biological productivity of lakes and reduces the amount of forage fish available to loons. Toxicity from mercury pollution of water bodies can lead to decreased reproductive success of loons as well.
Management and Research Needs.
Despite these difficulties, Common Loon populations in New York seem to be stable or increasing. Continuation of current management programs is necessary to maintain a healthy population. Public education is very important in reducing the risk of lead toxicity due to ingestion of lead fishing tackle and in decreasing disturbance caused by recreational activities such as boating. Such activities should be prohibited near nest sites and nursery areas during the breeding season. Signs providing information on the natural history of the Common Loon and the effects of human impacts on loons can be posted at boat ramps, beaches, campgrounds and other public access points to inform the public of the loons' needs. Monitoring programs, such as those conducted by the Adirondack Cooperative Loon Program and the Audubon Society of New York, Inc. have been established to evaluate the long-term reproductive success and changes in the breeding population of Adirondack loons, and help ensure that the haunting call of the Common Loon continues to echo off the Adirondack hillsides for years to come.
Additional References
Arbib, R.S., Jr. 1963. The Common Loon in New York State. Kingbird 13:132-140.
Dunning, J. 1985. The Loon, Voice of the Wilderness. Yankee Publishing, Inc., Dublin, New Hampshire.
Farrand, J., Jr. 1980. The Audubon Society Master Guide to Birding. Vol. 1: Loons to Sandpipers. Alfred A. Knopf, New York. Pp. 36-38.
McIntyre, J.W. 1988. The Common Loon, Spirit of the Northern Lakes. Univ. of Minnesota Press, St. Paul.
Parker, K.E. 1986. The Common Loon in New York State. New York State Department of Environmental Conservation, Wildlife Resources Center, Delmar, NY.
Peterson, J.M. 1988. Common Loon, Gavia immer. Pages 26-27 in Andrle, R.F. and J.R. Carroll, eds. The Atlas of Breeding Birds in New York State. Cornell Univ. Press, Ithaca, New York.
