Noteworthy More than half of grassland species are expected to face additional pressures because of climate change. Grassland habitats may dry out so much that they become uninhabitable for many grassland birds. The southwestern grasslands, which are vital to both breeding and wintering bird species, are threatened by many stressors in addition to climate change. Several bird species that are now common will probably be added to conservation concern lists in the near future unless additional measures are taken.
	Image: Grasshopper Sparrow by Sasha Keyel

Observations and Predictions

Grasslands in the Great Plains of the United States and southern Canada are predicted to get warmer with climate change. Southwestern grasslands are expected to become drier because of declining precipitation and higher temperatures, especially the Chihuahuan Desert grasslands of the southwestern U.S. and northern Mexico, which are critical wintering areas for many grassland birds.

In northern grasslands, additional precipitation is expected, but all or most grasslands are expected to become drier because warmer temperatures will cause increased evaporation. Variability in precipitation is also expected to increase; droughts, flooding, and extreme storms (such as hailstorms) are all expected to become more common. Increased atmospheric carbon dioxide will probably contribute to invasions of woody shrubs into grasslands.

Loggerhead Shrike by Brian Sullivan

The vulnerability of birds in grasslands is not as high as in other habitat types; however, 25 (57%) grassland species have medium vulnerability to climate change, and grassland birds are at risk for many reasons other than climate change. Six species stand out as especially vulnerable. Sharp-tailed Grouse and Lesser and Greater prairie-chicken are less likely than other grassland birds to move in response to changing conditions because they are closely tied to their leks where males display to attract females. Wilson’s Phalarope, Bobolink, and Dickcissel are long-distance migrants that may not be able to adapt quickly enough to changing conditions.

Species with a large proportion of the population wintering in the Chihuahuan Desert grasslands are also vulnerable because the habitat may dry out so much that it becomes uninhabitable. 

25 grassland species show medium vulnerability to climate change.

Climate change is expected to exacerbate declines in grassland birds that already have declining populations, and several species that are common now will probably be added to conservation concern lists in the near future unless additional conservation measures are taken. 

Dickcissel courtesy USFWS

Although most grassland bird species appear able to move in response to environmental changes, Christmas Bird Count data show that grassland birds were the only group of birds that failed to shift north during the past 40 years in response to warmer winter weather. Perhaps they did not shift because the quality of remaining grasslands in the north is too poor to sustain additional birds.

As woody vegetation invades grasslands, birds that specialize in grassland may be replaced by birds of shrubby or woodland habitats. Grassland species have different thresholds of tolerance for woody invasion; some, like Loggerhead Shrike and Northern Bobwhite, do best in mixed areas, but disappear when the grass becomes rare. Others, like Chestnut-collared Longspur, are intolerant of even a low percentage of shrub cover.

Key Steps

Large patches of healthy grasslands will need to be restored and protected throughout the United States to allow grassland birds to move north as temperatures increase. Conservation of wet grasslands and grasslands adjacent to wetlands is critical to allow birds that require wet habitats to persist.

Active management will be needed to maintain enough grassland to support the full suite of grassland bird species. In addition to shrub invasion and climate-related drying, grasslands are threatened by intensification of agriculture, over-grazing, invasive species, and suburban and urban development. Energy projects often target grasslands, making proper siting decisions essential for grassland bird conservation. For example, Sharp-tailed Grouse and Lesser and Greater prairie-chickens will not breed near tall structures such as oil rigs, wind turbines, or power lines. 

Chestnut-collared Longspur by Brian Sullivan

Collaborative efforts that consider grazing interests can allow grassland birds to coexist with cattle and other grazers in many grasslands. Moderate grazing may be required to maintain grasslands against woody invasion in some regions, especially in grasslands that coevoloved with native grazers.

Fire is essential for maintaining grasslands in most areas; in other regions, fire can favor nonnative invasive plants. Increased acreage of grasslands managed for wildlife is needed throughout the United States to stabilize grassland birds.

Conservation in Action

Wildlife conservationists have rallied around the plight of grassland birds in recent years. Increasingly, farm conservation programs have been designed to conserve birds and other wildlife, in addition to fighting erosion and supporting farm income. Many of the grassland conditions that benefit livestock production such as high grass cover and low shrub cover also benefit many of the most sensitive grassland
birds. Farmers, ranchers, and conservationists are working together to combat invasive species and protect grasslands.

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