As the days lengthen and the weather warms, some birds return to the Colorado Front Range that may seem out of place in a State known for prairie, mountains and canyons. Nevertheless, herons, egrets and ibis have long been residents of this region and man-made reservoirs have significantly increased their population along the South Platte and Arkansas River Valleys.
Great blue herons and a small number of black-crowned night herons are year-round residents of the Front Range urban corridor. The population of the latter increases dramatically during the warmer months when they are joined by snowy egrets, green-backed herons, American bitterns and white-faced ibis. Cattle egrets are also summer residents along the Front Range, attracted to the region by the combination of cattle ranches and reservoirs. In late summer, great egrets and yellow-crowned night herons may also wander into the State and occasionally turn up along the Front Range.
The presence of these waders, generally associated with Southeastern and Gulf Coast States, likely goes unnoticed by many (if not most) human residents of Colorado. Birders, fishermen and naturalists are certainly familiar with their presence but newcomers, visitors and novice birders are often surprised to find herons, egrets and ibis along the foot of the Rocky Mountains.