The Opal Creek watershed is home to both migratory and year-round bird populations. Most of the migratory birds found here breed during the summer and then migrate to locations further south in the fall, to spend the winter in warmer latitudes. These birds are known as neotropical migrants and include such species as the western tanager (Piranga ludoviciana) and the hermit thrush (Catharus guttatus). A few species are gone in the summer and come to Opal Creek to spend the winter, like the gray jay (Perisoreus canadensis) and the dark-eyed junco (Junco hymalis).
Many of the songbirds found here are only summer residents and nest in a variety of habitats. Some species like the orange-crowned warbler (Vermivora celata) and Wilson’s warbler (Wilsonia pusilla) nest on the ground while others like the warbling vireo (Vireo gilvus) and the tree swallow (Tachycineta bicolor) nest high up in the forest canopy. Many species nest in tree cavities; woodpecker species fill a key role in the forest ecosystem by annually excavating many cavities that are utilized by other species of birds and mammals. Some species of birds even nest behind waterfalls, like the black swift (Cypseloides niger) and the American dipper (Cinclus mexicanus), and are found abundantly at Opal Creek.
Many birds common to old-growth forests are found at Opal Creek. Such species include the Northern goshawk (Accipiter gentiles) and the Northern spotted owl (Strix occidentalis). Both of these large carnivores are adapted to flying through dense forests and display incredible maneuverability in the forests of Opal Creek.
Opal Creek is home to bird species that are carnivores, omnivores, herbivores, and insectivores. Carnivores include the owls, falcons, hawks and the carrion-eating turkey vulture (Cathartes aura). Omnivorous species include the common raven (Corvus corax) and the cedar waxwing (Bombycilla cedrorum). Herbivorous species include the blue grouse (Dendragapus obscurus) and the California quail (Callipepla californica), which forage in the trees and on the ground. Insectivorous species are common and feed in a variety of habitats. Species such as the pileated woodpecker (Hylatomus pileatus) feed on insects such as ants and termites that help to break down dead trees. Other species such as the common nighthawk (Chordeiles minor) and the Pacific-slope flycatcher (Empidonax difficilis) catch their insect meals on the wing.
Birds are essential in transferring nutrient energy up the food chain and distributing phosphorous, nitrogen, and other vital nutrients to new areas of the forest. Birds also act as dispersal vectors for seeds and pollen. Species such as the rufous hummingbird (Selasphorus rufus) are essential in the pollination of many spring flowers, and seed-eaters such as the red crossbill (Loxia curvirostra) and the Clark’s nutcracker (Nucifraga columbiana) are important in distributing the seeds of our forest’s conifers. Birds also play important roles in the dispersal of forest epiphytes, like the many mosses growing on tree branches, transporting the plant’s reproductive parts, or propagules, over long distances, either intentionally as nesting materials, or unintentionally when propagules ‘hitchhike’ on birds as they move through the forest canopy.