Sagebrush Sparrow

Artemisiospiza nevadensis

NatureServe conservation status

Global (G-rank): G5
State (S-rank): S3

External links

• NatureServe species report
• Google image search
• Google web search

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Species range

The breeding range of this species consists primarily of the Great Basin and other arid regions of the western U.S., including Nevada, Utah, and parts of Oregon and Idaho (Martin & Carlson, 2020; Peterson, 2020). A. nevadensis winters in the southwestern U.S. and northern Mexico, including parts of Arizona, New Mexico, and Baja California (Martin & Carlson, 2020; Peterson, 2020). A. nevadensis can be found year-round in the areas where wintering range overlaps with breeding range; in Utah this year-round range is limited to the southwestern portion of the state.

Migration

Of the species once considered part of the “Sage Sparrow” complex, A. nevadensis undertakes the longest migrations (Martin & Carlson, 2020). Green (1981) records the sagebrush sparrow arriving at its Utah breeding grounds by early March, with departures from the Uinta Basin to wintering grounds occurring in October to early November. Sage sparrows have historically been recorded flocking after nesting and prior to fall migration; in late August, juveniles can be seen forming small flocks (Green, 1981; Miller, 1968).

Habitat

The species is closely associated with sagebrush-dominated landscapes in both its breeding and wintering range. It prefers open areas with scattered shrubs, primarily sagebrush (Artemisia spp., particularly Artemisia tridentata), and avoids dense forests or grasslands. Martin and Carlson (2020) note that factors such as habitat connectivity, vegetation density, and vertical structure may be more important in habitat selection than specific shrub species; while A. nevadensis shows a preference for big sagebrush, it can also be found when sagebrush is interspersed with other shrubs. In southern Utah, birds are often found in blackbrush and other shrub communities associated with sandy soils (Gibson, 2025). Somewhat rare in mixed sagebrush-juniper; its preference for open areas makes the expansion of native tree species into shrublands a potential habitat concern (see Threats and Limiting factors) (Tack et al., 2023). Typically found breeding below an elevation of 1,700 m, though it has been found at higher elevations (Martin & Carlson, 2020).

Food habits

The Sagebrush Sparrow primarily feeds on seeds and insects, with a focus on seeds during the nonbreeding season (Degraaf et al., 1985; Polis, 1991). Grasses, pigweeds, and mustards are consumed in April, as well as late summer (Rotenberry, 1980). During the breeding season, it consumes a higher proportion of insects, with a wide range of arthropods ultimately accounting for 44% of food in the fall (Martin & Carlson, 2020). The exact balance of diet is heavily dependent on climatic conditions and the yield of arthropods and seed abundance in a given year.

Food is taken opportunistically on the ground, usually on the edges of vegetation; though also occasionally from the lower main stems and leaves of shrubs (Martin and Carlson, 2020).

Ecology

The daily time budget of sagebrush sparrows is somewhat determined by vegetation structure, with longer periods of inactivity, locomotion, and foraging, and a decrease in singing, when shrubs are removed (Wiens et al., 1986; 1987). Fighting is rarely observed between individuals of the species, and while males occupy breeding territories, they vary widely in size and shape (Green, 1981; Martin and Carlson, 2020; Rich, 1980). A. nevadensis can be found nesting closely with other species of aridland birds, and may occur in mixed-species flocks (Martin and Carlson, 2020). Members of the former Sage Sparrow complex have been recorded being predated by Townsend’s ground squirrels, common ravens, loggerhead shrike, great horned owls, and merlins (Martin and Carlson, 2020).

Nests may be parasitized by brown-headed cowbirds. There seems to be a correlation between records of parasitism and recent human disturbance, as cowbirds are uncommon in areas dominated by big sagebrush (Martin and Carlson, 2020).

Reproductive characteristics

Rich (1980) notes that sometimes individuals may arrive to breeding grounds already paired, which is an unusual trait among migratory songbirds. Males in the Bonneville Basin have been observed singing on their territory by late March; instances of mate selection during the month of May have been recorded to last less than an hour (Green, 1981; Martin and Carlson, 2020).

In the Uinta Basin, pairs of birds have been observed selecting nests over the course of several days (Green, 1981). Once selected, males sing and defend the site while females construct the nest. The Sagebrush Sparrow builds open cup-shaped nests, composed of small twigs and coarse grasses/forbs; typically placed low in sagebrush or other shrubs; Green (1981) records nests in Utah an average of 26 cm above the ground in rabbitbrush, hopsage, saltbush, and big sagebrush, as well as ground nests beneath rabbitbrush.

Clutches usually consist of 3 to 4 eggs (Martin & Marlson, 2020). Green (1981) observed the mean clutch size of nests in Utah to be 3 eggs. Incubation lasts about 10 to 16 days from the completion of egg-laying period (Martin Carlson, 2020). Typically eggs are only incubated by the female (Green, 1981). Young birds fledge approximately 9 to 11 days after hatching (Martin & Carlson, 2020). Parents have been observed feeding and giving warning calls to young that have left the nest, but there is no information on the length of time this behavior continues (Martin & Carlson, 2020).

Threats or limiting factors

A. nevadensis is primarily threatened habitat loss, as the geographic extent and quality of the sagebrush biome it relies on is changing. Conversion of sagebrush habitats to agricultural uses, energy infrastructure, and urban developments reduces the available breeding and foraging areas for sagebrush sparrows. Encroachment of native and non-native species is also a primary threat facing this species. The introduction and spread of invasive grasses, such as cheatgrass (Bromus tectorum) and crested wheatgrass (Agropyron cristatum), increases competition for native plants and increases the frequency and intensity of wildfires, which can destroy sagebrush habitats.

The sagebrush biome has a complicated management history that has brought many changes to the plant communities sage sparrows are reliant on. From the mid 1800s to the 1930s, plant communities were altered by livestock grazing which actually increased in sagebrush cover as herbaceous competition was removed (Reminton et al., 2021). Over the next several decades, management turned to increasing available forage for livestock, often by removing sagebrush through mechanical and chemical means, and introducing non-native grasses. These changes also likely spurred the encroachment of native conifer species into areas historically dominated by sagebrush (Miller et al., 2019). The result has been a sharp decrease in available sagebrush habitat; by some estimates, as much as 45% of the sagebrush biome present before European settlement has been lost (Miller et al., 2011). It is very likely that habitat loss driven by big sagebrush removal, and the increase in grasses/forbs for livestock grazing, had a large impact on the distribution and long-term population trends of A. nevadensis (Braun et al., 1976). Indeed, because A. nevadensis is so closely associated with sagebrush habitats, it follows that any activity that reduces sagebrush availability can influence sparrow populations (Martin & Carlson, 2020).

North American bird declines are not uniform across all biomes; rather, grasslands and aridlands are especially imperiled (Saur et al., 2017; Rosenberg et al., 2019). Aridland birds including the sagebrush sparrow are facing a long-term decline, largely due to habitat loss. Anthropogenic threats such as urban development, agriculture/grazing, and energy extraction all put pressure on sagebrush dominated landscapes; longer-term issues such as drought, changing fire regimes, and the introduction of invasive plants also pose conservation concerns (NABCI, 2022; Remington et al., 2021). Expansion of human-built environments also increases the likelihood of habitat damage by exotic species, and of predation by feral cats; however, as Martin and Carlson (2020) note, these are only qualitatively recognized and require further study to quantify these threats.

Conservation for species such as the sagebrush sparrow requires a habitat-level assessment involving numerous partners. The North American Bird Conservation Initiative (2022) estimates that more than half of the breeding distribution of aridland birds is on public land; furthermore, more than two-thirds of the distribution of the sagebrush sparrow occurs on BLM land. This statistic underscores the vital role that the federal government, state agencies, and their partners have in conserving the species. In 2021, the USGS in collaboration with the Western Association of Fish and Wildlife Agencies, the BLM, and the USFWS published part one of a “Sagebrush Conservation Strategy,” intended to provide guidance and bring the efforts of numerous agencies and conservation partners towards the common goal of protecting the entire sagebrush biome (Remington et al., 2021). A further report was created to inform and provide a spatially explicit conservation design for part two of the strategy; this report identifies “core sagebrush areas” as targets for conservation action using metrics that have been tested and explicitly shown to correlate with sagebrush songbird abundance and population trends (Doherty et al., 2022; Kumar et al., 2024). This management strategy hopes to bring recognition to the fact that disturbed sagebrush habitat is vulnerable to further disturbance and damage, and promotion of the idea that habitat treatments should be confined to sites with the largest potential benefit. With careful management, habitat restoration and preservation, it is possible that Sagebrush sparrow populations may stabilize.