Migration & Flight
Because loons have such large, heavy bodies, they need a lot of room, almost a 1/4 mile, to get airborne and take flight.
Congregating
As the summer progresses into fall, it is apparent that loons are coming and going more frequently. Sometimes there are no birds observed on a lake, while at other times, there are more than usual. It is possible to see 60 or more loons on an Adirondack lake by late September/early October.
Molting
During this time, adults molt from their black and white breeding feathers to a dull gray winter plumage. Thousands of feathers dot the water and lake shores while the birds preen and preen to lose their breeding plumage. Within a matter of a few weeks, it becomes difficult to tell adult and juvenile birds apart because their plumage is so similar.
Departure
By Thanksgiving, loons are rarely seen on Adirondack lakes, except for a few stragglers observed during a warm fall. Often, when a storm comes through, people report seeing more than a hundred loons feeding together after stopping to rest on a large lake. Sometimes, a lone gray juvenile can be seen in late November on a small pond fringed with ice, only to leave the next day.
Flight
Flying is energy-intensive for loons. Their dense bones make take-off difficult— loons require about 1/4 mile of runway to take to the sky. You will often see them “running” on the water as they build up momentum. Once they reach a higher altitude, they have to continue to flap their wings until they reach their destination. Loons cannot soar as eagles, vultures, and other migratory birds.
Some loons will fly short distances between lakes to feed during the summer months to get adequate fish and resources. During migration, loons can fly up to 70 mph as they aim for their wintering grounds.
Wintering
Although Common Loons breed in the Adirondack Park during the summer, they also spend 5 to 7 months each year (October/November – April/May) along the Atlantic coast. Loons from other areas may winter on large fresh-water reservoirs in some southern states, including Tennessee and South Carolina.
Migration and wintering on the ocean can be very stressful for loons and other birds. Loons expend a significant amount of energy during migration since they must fly continuously for hours (they are not capable of soaring like a vulture or hawk), until they get to a “stopover” lake or the coast itself.
Common Loons in wintering plumage have a mottled look. This one is regrowing its breeding plumage.
Once they arrive at their oceanic wintering area, loons change their diet from freshwater fish, crayfish, and invertebrates to saltwater prey. They must also activate their salt glands to expel the salt they take in while feeding and living on the ocean. In the winter, loons experience a complete molt— losing both their body and wing feathers for a one month period. During this period, they are flightless until their wing feathers re-grow, and they utilize much needed stores of energy to grow their new plumage.
Loons are exposed to a variety of potential threats during migration and on their wintering areas on the coast, including oil spills, commercial fishing nets, and coastal storms.
To learn about our research on the migration of Common Loons, click the link below!