Steller’s jays are a striking blue colored bird found predominantly in western North America. Their range extends along the Pacific coast from southern Alaska down through western Canada to Washington state. They are also found inland throughout mountainous regions of the western United States and into parts of Mexico.
Quick Facts
Here are some quick facts about where Steller’s jays are found:
- Range extends along the Pacific coast from southern Alaska to Washington state
- Found inland throughout mountainous regions of the western U.S. and parts of Mexico
- Closely associated with pine and oak forests
- Rare east of the Rocky Mountains
- Highest densities found in the Pacific Northwest and Sierra Nevada mountains
Detailed Range and Distribution
Steller’s jays have a relatively limited range constrained to the western portion of North America. Their distribution can be divided into two main population segments – a coastal segment and an inland segment.
Coastal Distribution
Along the Pacific Coast, Steller’s jays range from southern Alaska down through coastal British Columbia, Washington, Oregon and into northwest California. Their range extends inland variable distances along this coastal region based primarily on the extent of dense coniferous forest habitat.
In Alaska, they are found throughout the Alexander Archipelago including Admiralty, Baranof, Chichagof, Kupreanof, and Prince of Wales Islands. They are also well established on the mainland of southeast Alaska. Coastal populations extend south along the coast of British Columbia into Washington state where they are common in coastal forests.
In Oregon, Steller’s jays are found throughout the Coast Ranges. Coastal populations extend south into northwest California approximately to Sonoma County which represents the southern limit of their coastal distribution.
Inland Distribution
Steller’s jays have a widespread distribution through mountainous and high elevation terrain of the western United States and Mexico. Their range extends east from the Pacific Coast into the Cascade Mountains, Sierra Nevada Mountains, Transverse Ranges, Peninsular Ranges, and isolated high elevation sites in the Mojave Desert.
In the Cascade Mountains, Steller’s jays are found from southern British Columbia south through Washington and Oregon. They occur on both the west and east sides of the Cascades crest. Their distribution extends south in California down to about Lake County.
In the Sierra Nevada Mountains, they are found on both the west and east sides. On the west side, they occur from about Fresno County north to the Oregon border. On the drier east side, their range extends from about Kern County north to southern Oregon.
Steller’s jays inhabit the Transverse and Peninsular Ranges of southern California. Isolated populations may also occur in higher elevation sites in the Mojave Desert such as the Spring and New York Mountains. Their distribution extends south into the mountains of Baja California in Mexico.
East of the Cascades and Sierra Nevada, Steller’s jays distribution becomes patchy and disjointed in the Intermountain West. Scattered populations occur in mountain ranges of eastern Oregon, Nevada, Utah, western Colorado and Wyoming, and northcentral New Mexico. They are rare and local east of the Continental Divide with the exception of an isolated population in the Black Hills of South Dakota.
Forest Associations
Within their west coast and inland mountain ranges, Steller’s jays closely associate with montane coniferous forest habitat. They predominately inhabit pine dominated forests of various types.
Coastal populations mainly occupy Sitka spruce and western hemlock forests of Alaska to Oregon. They also inhabit mixed evergreen forests consisting of Douglas-fir, redwood, tanoak, madrone, and live oak along the northern California coast.
Inland populations are strongly tied to various pine dominated habitats including ponderosa pine, Jeffrey pine, lodgepole pine, whitebark pine, and pinyon-juniper woodlands. They secondarily inhabit mixed conifer forests, Douglas-fir forests, and oak woodlands.
Steller’s jays are generally absent from higher elevation subalpine forest and alpine habitats above treeline. However, during the breeding season they may ascend short distances into subalpine zones. They are also largely absent from low elevation deciduous woodlands and shrublands. As a result, their elevational range is generally restricted to between 2,500 – 9,000 ft throughout most of their inland range.
Population Concentrations
While Steller’s jays occupy a broad geographic range along the west coast and mountainous west, their distribution is somewhat patchy and populations are not equally dense throughout their entire range.
Their highest population abundances occur within two main regions – the Pacific Northwest and the Sierra Nevada Mountains of California and Nevada.
Pacific Northwest
The core of the Steller’s jays population and range occurs within the Pacific Northwest, centered on northwest Oregon and western Washington. Populations reach their highest densities within the Puget Trough region and west slopes of the Cascade Mountains where extensive old growth forest provides optimal habitat conditions.
They are likewise abundant on the west side of the Oregon Coast Range and into the Willamette Valley. Coastal populations north into British Columbia are sparser where more precipitation supports denser mesic conifer forest less favored by jays.
Sierra Nevada
The Sierra Nevada Mountains host a large, dense population of Steller’s jays, centered on the west slope and high elevation east side which provides more favorable forest habitat. They are abundant in ponderosa pine, Jeffrey pine, white fir, and mixed conifer zones which offer their preferred habitat.
Densities are lower on the western foothills and east side mid-elevations where oak woodlands and drier pine forests dominate. Populations extend north through the Sierra into eastern Cascades ranges of northern California and southern Oregon.
Other Regions
Elsewhere throughout their range, Steller’s jays generally occur at lower densities in more patchy, discontinuous distributions. Coastal populations in southern Alaska, while locally common on the Alexander Archipelago, are more sporadic on the mainland.
Inland populations become increasingly scattered further east in the Rocky Mountains and Great Basin ranges where habitat conditions become marginal. The Black Hills of South Dakota represent an isolated population stronghold east of the Continental Divide.
Southern populations in Mexico’s Sierra San Pedro Martir and Sierra Juarez are restricted to higher elevation islands of pine-oak forest. On the whole, densities progressively decline at the southern and eastern periphery of the Steller’s jays range.
Habitat Preferences
Several key habitat factors influence the distribution of Steller’s jays across their range in western North America. Their close association with coniferous forest habitats, particular pine dominated woodlands, is a major driver shaping their range.
Forest Composition
Steller’s jays show a strong preference for conifer-dominated woodlands throughout their range. They favor various types of pine forest including ponderosa, lodgepole, Jeffrey, and pinyon pine. They also inhabit mixed conifer forests with Douglas-fir, fir, and spruce.
They tend to prefer open canopied, mature pine forests with complex structure providing nesting cavities. Denser, closed-canopy fir and spruce forests are used less frequently. Deciduous forests and woodlands dominated by aspens, oaks, or other deciduous trees are largely avoided.
Elevation
Elevation is a major factor governing their distribution. Steller’s jays are restricted to higher elevation mountains and foothills from 2,500 – 9,000 ft where conifer forest habitat persists. They are absent from low elevation valleys and basins below around 2,000 ft dominated by shrublands or deciduous woodlands.
Their upper elevational limit reaches up to treeline around 9,000 ft. At higher subalpine elevations above treeline, their occurrence is sparse and erratic.
Climate
Steller’s jays distribution reflects their preference for the moderate climate of high elevation forests. They are most abundant in areas with a predominantly marine-influenced climate characterized by cool summers and mild, wet winters.
They tend to be less common in more continental climates with colder winters and warmer, drier summers such as the interior Great Basin. Deep winter snowpack may limit their winter distribution at the highest elevations.
Forest Structure
Mature, open canopied pine forests with large trees, snags, and deadwood appear optimal for Steller’s jays. These older forests provide nesting cavities in dead snags and an open understory favorable for caching and foraging.
Younger, denser forests are used but support lower densities. Recent timber harvesting can maintain suitable habitat patches if sufficient large trees and snags are retained.
Range Changes Over Time
The overall range and distribution of Steller’s jays has been generally stable and unchanged over past centuries. However, local shifts in their abundance and density have occurred in some regions in response to habitat changes.
Population Expansions
Steller’s jays have expanded their range and increased in number in some areas as a result of human land use changes. Logging and fire suppression in the Pacific Northwest have opened denser forest canopies and maintained nesting and caching habitat. Jays have colonized timber harvest areas and increased alongside forest fragmentation.
In California, they have also benefited from fire suppression and selective logging expanding into open, park-like ponderosa and Jeffrey pine forests. Natural habitat recovery in the Black Hills has allowed jays to colonize a formerly marginal area distant from their main range.
Population Declines
Steller’s jays have declined or disappeared from some portions of their former range where habitat loss has occurred. Coastal populations in northwest California have contracted with extensive redwood logging. In Mexico, habitat loss has caused declines at the southern margin of their range.
In British Columbia, jay numbers decreased with maturation of coastal forests but have rebounded with recent larger-scale timber harvests. Climate change impacts on high elevation habitats may also cause future distribution shifts.
Urban Adaptability
In addition to native forest habitats, Steller’s jays have proven highly adaptable to human-altered environments. They are regular inhabitants of parks, residential areas, and urban neighborhoods within their range where tall trees occur.
Jays make use of ornamental conifers, oaks, and other urban trees and shrubs for nesting, roosting, and food caching. They are frequent visitors to bird feeders and other human food sources. Urban populations may be increasing and expanding with human development across the western states.
Conclusion
In summary, Steller’s jays occupy a distinct geographic range confined largely to the coniferous forests of western North America. Their primary range extends along the Pacific coast and throughout high elevation inland mountains. Core populations centers occur in the Pacific Northwest and Sierra Nevada. Local shifts in abundance have occurred with forest disturbances and urbanization, but their distribution has remained generally stable.