Pelicans are typically associated with coastal environments, so their presence in a landlocked state like Colorado often comes as a surprise. However, these large aquatic birds are present across the state’s vast network of inland waterways. Colorado provides important summer habitat for a specific, non-coastal species, confirming that pelicans utilize freshwater resources far from the ocean.
The American White Pelican in Colorado
The pelicans observed in Colorado are exclusively the American White Pelican (Pelecanus erythrorhynchos). This species is one of the largest birds in North America, reaching a body length up to 70 inches and a wingspan approaching 10 feet. Their plumage is uniform white, contrasted by broad black flight feathers visible along the trailing edge of their wings.
Unlike the coastal Brown Pelican, the American White Pelican does not dive from the air. Instead, they cooperate in groups to herd fish before scooping them up in their large, yellowish bill and pouch. During the breeding season, a distinct, vertically flattened knob develops on the male’s bill, which is shed once the nesting period is underway. Colorado is within the summer breeding and non-breeding range for these freshwater-dependent birds.
Seasonal Migration and Timing
The presence of the American White Pelican in Colorado is tied entirely to its annual migratory cycle. They travel vast distances across the continent, arriving in the state in early spring, generally around late March or April. This arrival follows the thaw of large reservoirs and lakes, allowing them to establish breeding colonies and access food sources.
Pelicans remain throughout the summer, focusing on feeding and raising their young at established nesting sites. Colorado provides a secure environment for their large, ground-nesting colonies, which are usually situated on isolated islands within bodies of water. Departure begins in the late summer and fall, typically from September through October, as they migrate south. Their winter destinations are along the Gulf Coast of Mexico and the southern United States, where water remains open and food is abundant.
Primary Viewing Locations and Habitats
Pelicans in Colorado seek large, shallow freshwater habitats that offer abundant fish populations for foraging and secure, isolated areas for nesting. The most reliable places to view them are the state’s large reservoirs and lakes, especially those with protected islands. Riverside Reservoir in Weld County and Antero Reservoir in Park County are known to host significant nesting colonies.
Other popular viewing spots include Barr Lake State Park and Cherry Creek State Park, which serve as important stopovers near the Denver metropolitan area. State parks and wildlife refuges, such as the Rocky Mountain Arsenal National Wildlife Refuge, are frequent congregation points because the birds require large, undisturbed expanses of water and shoreline.