Approximately 238 species of birds have been documented on or near the Monument, 36 of which are common and 40 are accidental visitors. The Monument provides habitat for year-round residents, migratory species that breed on the site, winter residents, and migrants that are passing through to or from breeding grounds.
Mature sagebrush stands are perhaps the most important habitat on the National Monument because large blocks of sagebrush in good condition are a dwindling resource in the Columbia Basin Ecoregion. Horned lark (Eremophila alpestris) and meadowlark (Sturnella neglecta) are the most abundant breeding birds in the sagebrush/bunchgrass habitats. Brewer’s sparrow is more common in the three-tip sagebrush communities at higher elevations. The Brewer’s sparrow and sage sparrow are sagebrush obligates and require sagebrush stands for nesting. Other species closely tied to sagebrush occurrence include loggerhead shrike and sage thrashers. Loggerhead shrikes are commonly observed in dense sagebrush stands of the Monument.
The large expanses of bunchgrass habitat on the Monument provide hunting, nesting, and resting areas a number of bird species. Native bunchgrass habitat is used for foraging by a variety of raptors including Swainson’s hawk (Buteo swainsoni), golden eagles (Aquila chrysaetos), prairie falcons (Falco mexicanus), short-eared owls (Asio flammeus), and red-tailed hawks (Buteo jamaicensis), among others. Meadowlarks, horned lark, and grasshopper sparrow (Ammodramus savannarum) are some of the ground-nesting birds that are commonly found in bunchgrass habitat on the Arid Lands Ecology (ALE) Reserve. Burrowing owls (Athene cunicularia) and Swainson’s hawks also have been documented nesting and feeding in bunchgrass habitat.
Riparian habitat is a scarce but important resource for birds on the National Monument. The sharp contrast with the adjacent shrub-steppe habitat, the presence of trees, and the abundant cover make these areas focal points for predator and prey. Although the total area occupied by riparian habitat is small, the avian diversity is higher than the surrounding shrub-steppe. Riparian habitats are used by neotropical migrants such as, the western wood peewee (Contopus sordidulus), Say’s phoebe (Sayornis saya), western kingbird (Tyrannus verticalis), and resident downy woodpeckers (Picoides pubescens), and northern flickers (Colaptes auratus). Trees are rare on the Monument landscape and therefore provide an important resource for a number of birds. Raptors will perch, hunt from, or nest in trees in the riparian zone, or they may be attracted by the presence of prey species. The barn owl (Tyto alba), long-eared owl (Asio otus), great-horned owl (Bubo virginianus), red-tailed hawk, sharp-shinned hawk (Accipiter striatus), American kestrel (Falco sparverius), and Swainson’s hawk regularly use riparian zones. Chuckar (Alectoris chukar), California quail (Callipepla californica), and mourning dove (Zenaida macroura) find abundant cover from predators in the riparian zones. Red-winged (Ageliaus phoeniceus) and yellow-headed blackbirds (Xanthocephalus xanthocephalus) breed along watercourses. Songbirds documented using the Monument riparian zones include the ruby-crowned kinglet (Regulus calendula) and golden-crowned kinglet (R. satrapa), warbling vireo (Vireo gilvus), orange-crowned warbler (Vermivora celata), yellow-rumped warbler (Dendroica coronata), MacGillivray’s warbler (Oporornis tolmiei), and Wilson’s warbler (Wilsonia pusilla), among others. In the winter, riparian zones are used by dark-eyed junco (Junco hyemalis), white-crowned sparrow (Zonotrichia leucophrys), American robin (Turdus migratorius), Townsend’s solitaire (Myadestes townsendi), and other species (LaFramboise and LaFramboise 1998).
Riverine habitat along the Hanford Reach is used extensively by mallards (Anas platyrhynchos), Canada geese (Branta canadensis) and other waterfowl for wintering, and the island habitats for nesting. Great blue herons (Ardea herodias), great egrets (Ardea alba), black-crowned night-herons (Nycticorax nycticorax), and other water-related birds have also been noted using the river corridor and islands. Double crested cormorants (Phalacrocorax auritus), American white pelicans (Pelecanus erythrorhynchos), several species of gulls and terns also use these areas.