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State of the Birds Report

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                    At a Glance

Aridlands make up approximately 19%, or 369 million acres, of the lower 48 states. Of those acres, 39%, or 145 million acres, are in private ownership.

• Private lands contain 40% of breeding and 43% of wintering aridland bird distributions.

• Many aridlands regions are popular for human settlement. Arizona's population increased over 300% between 1960 and 2000. Projected future population increases could increase development pressure on important bird habitats.

• Two million acres of private protected aridlands support a disproportionately high percentage of breeding and wintering bird distributions.

Image: Sagebrush by Gerrit Vyn  
These lands are an important part of the forage base for our sheep operation, and they support sage-grouse. We are honored to protect these lands in perpetuity.
Brian Bean of Lava Lake Land & Livestock, who has signed 12,000 acres of conservation easements on his ranchlands in the Pioneer Mountains of Idaho

Aridland Birds on Private Lands

Aridlands include some of our country’s most unique habitats: deserts, sagebrush, chaparral, and other habitats characterized by low precipitation and a highly variable climate. About 19%, or 369 million acres, of the lower 48 states are aridlands. In the U.S., about 39%, or 145 million acres, of aridlands are privately owned, about 54% are publicly owned, and 7% are Native American–owned. About 1%, or 2 million acres, of privately owned aridlands have some kind of conservation protection via ownership or easement.

About 40% of aridland bird species are of conservation concern, and more than 75% are declining. In the breeding season, there are 36 obligate species of aridland birds, with about 40% of their U.S. distribution on private lands. In the winter season, there are 26 obligate species of aridland birds, with about 43% of their U.S. distribution on private lands.

Several aridland bird species are noticeably more prevalent on private than public lands. These include the federally listed Black-capped Vireo and California Gnatcatcher (99% and 81%, respectively, on private lands); Chihuahuan Raven, Pyrrhuloxia, and Scaled Quail of southern desert shrublands (77%, 76%, and 74%, respectively, on private lands); and a miscellaneous assemblage of other species (Lark Sparrow, 79%; Bell’s Vireo, 62%; Wrentit, 62%).

Among the major types of aridlands, the best studied are the extensive sagebrush habitats of the Great Basin desert and surrounding areas between the Cascade–Sierra Nevada and Rocky Mountains. Analyses of lands within the current and former range of the Greater and Gunnison Sage-Grouse (species that rely on this aridland habitat type) indicate that 31% of this area is in private ownership. For Greater Sage-Grouse, 36% of their distribution is on private land, with 1% of these birds on private protected lands. The equivalent numbers for Gunnison Sage-Grouse are 26% of their distribution on private land and 2% on private protected lands, demonstrating that protected aridlands parcels contribute to the conservation of these iconic sagebrush species.

Sagebrush country in Montana, by Linda Poole, courtesy of Sage Grouse Initiative 


Conservation Successes

The 2 million acres of private protected aridlands support a disproportionately high percentage of bird distributions, which is an encouraging sign that some of the best aridland bird habitats have been preserved. For some species, this proportion is especially high, such as Lawrence’s Goldfinch in the breeding season, where over 2% of the estimated occupancy of this species is found on private protected lands, almost all in California. Similarly, almost 2% of the Wrentits on private lands in the U.S. are found on private protected lands in Oregon and California.

Pyrrhuloxia by Clifford A. Cathers 

While most other species of aridland birds are declining, Bell’s Vireo shows significant population increases of 3% per year from 2000 to 2010, according to the North American Breeding Bird Survey. Major habitat restoration efforts in California and along the lower Colorado River by federal and state agencies and non-profit organizations have increased habitat availability for the vireo, which has responded by recolonizing areas it hasn't used for many years.

In Arizona, the Sonoran Desert Conservation Plan is an ambitious effort by the local government and partner groups in Pima County to protect the region’s rich cultural heritage, biodiversity, and natural landscapes. Originally developed in 1997 in response to the listing of the Cactus Ferruginous Pygmy-Owl, the plan now has become one of the nation’s most comprehensive conservation and land-use planning efforts. With a biological goal to ensure the long-term survival of the full array of plants and animals found in Pima County, the plan protects key habitats via purchase, conservation easement, or through management lease, planning, and zoning that regulates development in particularly vulnerable habitats. The plan has protected more than 230,000 acres of Sonoran desert and semi-desert grassland habitat, including 87,000 acres of private land managed to comply with a local floodplain ordinance that minimizes impacts on riparian habitat. These lands are primarily along ephemeral streams prone to flooding during summer rain, and they contain important habitats for many aridland birds, such as Elf Owl, Gilded Flicker, Phainopepla, Pyrrhuloxia, Costa’s Hummingbird,
Bell’s Vireo, and Varied Bunting.

Aridland Bird Distribution 

The Wrentit—a bird of the Pacific Coast chaparral—has more than 60% of its distribution on private lands. It is among the eight aridland obligate bird species that are more prevalent on private lands than average. Wrentit by Ganesh Jayaraman; . 


Silver Creek at Silver Creek Preserve in Idaho by
Harold E. Malde
Conservation Challenges 

Aridland birds are faring poorly, especially compared to birds in other habitat types. Many of the best and most productive aridland bird habitats are privately owned. For example, an analysis of land ownership in the Intermountain West Joint Venture area revealed that although 30% of the land area is privately owned, 70% of the palustrine wetlands (such as inland marshes) in this region are privately owned, a habitat type that is extremely important to aridland birds. The highest quality aridlands were the first to be claimed and settled following homesteading in most western states, and they have been mostly converted to other uses, such as agriculture and human settlement.

Furthermore, many aridland regions are among the most popular for residential development in the entire country. In Gunnison County, Colorado (which supports more than 80% of all Gunnison Sage-Grouse), the population is predicted to double by 2050. In Arizona, the population increased over 300% between 1960 and 2000, and projected future increases are among the highest in the nation. Assuming most of the current network of public and tribal lands stays intact, almost all of this growth will be concentrated on private lands.


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