In the effort to find a good place to raise a family, some of the park's part-time residents have to travel great distances. This is especially true for the park's water birds. While a few water birds (some mallards and Canada geese) are year-round residents in or near the park, many migrate long distances. Some species, such as the occasional snow goose visitors, move through the area on their way to northern breeding grounds. Many birds, such as some Canada geese, return to the park from the Gulf Coast area to spend the summer.
Migrating birds follow traditional north-south migration routes or flyways. Flyways are aggregations of several routes that appear net-like when plotted on a map, and various routes follow north-south oriented surface features like mountain ranges and river valleys. Some of the routes are frequented by the majority of migrating birds, such as the main route of the Central Flyway through Nebraska roughly following the Platte River. The Central Flyway map (provided courtesy of the US Fish & Wildlife Service) shows that there are some routes used less frequently, and by smaller numbers of birds. Rocky Mountain National Park is crossed by some of these less frequently used routes. Thus we have many occasional or rare water bird visitors such as the lovely American avocets, wood ducks, tundra swans, American white pelicans, and white-faced ibis.
Migration is not without challenges. One group of migrants, the grebes (Podicipedidae), sometimes has problems in or near the west side of the park. Because they migrate during times of rapidly shifting mountain weather conditions in the spring and fall, grebes can mistake icy roads for shining water surfaces and land. Because their take off involves a "running start" on water, they are trapped. On a few occasions when this has happened, the Colorado Division of Wildlife has had to come to the rescue by collecting the birds and taking them to open water so they could continue their journey.
Recognizing the challenges of the migration, the distances they must fly, the possibilities for habitat destruction in their part-time homes outside the park, we should all be thankful when we catch a glimpse of any of these tough and beautiful water bird migrants.