Seasons of Wildlife
Canada geese and trumpeter swans typically lead the northward flight of waterfowl in late March and are followed shortly thereafter by mallards, northern pintails and a variety of diving duck species. Impressive flocks of phalaropes, sandpipers and plovers buzz mudflats during late spring amid the constant din of up to 20,000 pairs of Franklin’s gulls that are establishing colonies in isolated emergent marsh areas.
Breeding vocalizations of numerous sparrow species interrupt the early morning quiet in June. Several thousand stately American white pelicans can be seen foraging on various impoundments, and a true natural resources success story can be witnessed by nesting bald eagles which returned to the refuge in 1992. July mornings showcase numerous squadrons of ducklings scattered along shorelines and areas of emergent vegetation, as well as a patchwork of molting waterfowl in open water areas.
Not long after the mass of fall migrating shorebirds have filled up on protein-rich invertebrates and headed to more southerly locations, the refuge is filled with a variety of south-bound waterfowl. As many as 75,000 ducks, 15,000 geese and 1,500 greater sandhill cranes use the refuge as a migratory stopover site.
In late fall once the marshes have frozen solid and fields are snow-filled, resident birds search for food and winter cover along with winter migrants, including rough-legged hawks, snow buntings and an occasional snowy owl.
The refuge supports 17 species of breeding ducks as well as Canada geese and trumpeter swans. In an average year 7,500 pairs of ducks and 250 pairs of Canada geese nest at the refuge. The diversity of wetland and upland habitat provides excellent protection for ducklings, goslings and molting waterfowl.
Colonial nesting birds include Franklin’s gulls, black terns, Forester’s terns, eared grebes and black-crowned night-herons. Smaller colonies of western grebes, great blue herons and double-crested cormorants also nest here.
Moose have roamed the refuge for decades. In the early 1990s, their population began to dramatically decline. Researchers say the decline may be a result of disease, parasites, a warming climate or some combination of all three.
The refuge has two resident packs of gray wolves. These wolves roam the entire area during the winter months, but favor the grassland and forestland on the east and south sides during the rest of the year.
In 1992, after a 30-year absence, bald eagles once again began nesting on the refuge. One nest can be observed near the Parker Pool observation deck.