The park is home to a number of bird species. Some of these birds are year round residents but most occur in the park during specific seasons. The distribution of birds in the park can be broken into the life zones of the park, which is highly dependent on the elevation. The lowest areas of the park (below 3500 feet) are characterized by having mature forests of Douglas-fir, western red cedar, grand fir and western hemlock. This zone provides suitable habitat for northern spotted owl (Strix occidentalis caurina), and marbled murrelet (Brachyramphus marmoratus marmoratus). The distribution of either of these threatened birds is not well documented in the park. Many other birds occur in this zone which are seasonal visitors or year around residents. The next zone of the park (3500 to 5000 feet) is characterized by its mixed forests of western white pine, western hemlock, and Pacific silver fir. Many birds occur in this zone depending on weather, food sources, migration, and breading time. The elevational zone in the park which attracts numerous visitors in the summer is between 5000 and 6500 feet, this is where Paradise and Sunrise are located.
This zone is characterized by mixed forest and subalpine meadows. The trees are primarily subalpine fir, mountain hemlock, Alaska yellow cedar, and whitebark pine and they tend to grow in clumps. There are many birds found in this especially in the summer. Over 80 square miles of Mount Rainier National Park is above 6500 feet. This zone is characterized by snowfields, glaciers and bare rock outcrops. There are many plant communities associated with these exposed areas. Insects and spiders are found at these elevations due to wind dispersal onto snowfields and glaciers. These organisms serve as food for numerous birds which visit the snowfields. The northern spotted owl (Strix occidentalis caurina) is the only bird species listed on the USFWS list of threatened and endangered species that permanently inhabits the park.
Marbled murrelets (Brachyramphus marmoratus marmoratus) have been observed inside and outside the park and nest in the park. Bald eagles (Haliaeetus leucocephalus) and peregrine falcons (Falco peregrinus) are also listed species, but probably just migrate through the park. They have been sighted in the park but there is no record of either species nesting in the park. There several bird species found in the park which are sensitive species, including the northern goshawk (Accipiter gentilis), Harlequin duck (Histrionicus histrionicus), and little willow flycatcher (Emphidonax traillii brewsteri). There are several birds inhabiting the park which are on the Washington Department of Wildlife, Nongame Program's "List of Species of Special Interest in the State of Washington". The federal and state lists need to be periodically reviewed, and all species occurring in Mount Rainier evaluated and possibly monitored. Reported declines of many resident-migrant birds have stimulated interest in avian population trends across North America. Suggested mechanisms driving these declines include habitat loss (Rappole and McDonald 1994; Sharp 1996; Wilcove et al. 1998), habitat fragmentation (DeSante and George 1994), habitat succession (Sharp 1996), increased nest predation (Morse and Robinson 1999) and nest parasitism, and increased mortality during migration.