Common loons (Gavia immer) are found in Alaska, Canada, parts of the northern US, and as far east as Greenland and Scotland. They specialize in catching fish for food, sometimes diving as deep as 200 feet to obtain them. Their nests are built on islands or near remote lakes to discourage ground-based predators, but their eggs and nestlings can be eaten by birds, turtles, and even fish.
Estimates from data collected over the past 20 years suggest that Glacier National Park harbors approximately 20% of Montana’s breeding loons, yet reproduction rates appear to be lower than other parts of the state. Evidence indicates that loons, listed by Montana as a Species of Special Concern, are adversely impacted by humans at nesting sites.