Grassland birds are the most imperiled habitat-based group of birds in North America. Grassland songbirds have been in decline since their populations were first estimated in the 1960s. This trend is largely consistent across types of grassland birds: migrants and residents, gamebirds, shorebirds, songbirds, hawks, and owls. This is alarming as birds are indicators of ecosystem health. People are largely unaware of the importance (economic, esthetic, cultural) of birds and that many changes in land development, land use policies, and grazing can occur that would benefit grassland habitats and birds, with minimal financial costs to ranchers, and perhaps even benefits.
Cliff Wallis Photo.
Examples of simple changes include consideration for: the timing of disturbances relative to bird breeding activities; the area requirements of birds beyond pasture fences to achieve habitats more appropriate in size; and the rotation of grazing among pastures to increase habitat heterogeneity with no change in animal production.
Conservation Relevance for the Northern Great Plains:
For millennia, grassland wildlife specialized on habitats created by free-ranging grazers. Modern land uses have created a vastly different landscape that is fragmented and altered in terms of dynamic ecosystem drivers which once maintained key habitats.
Interactions between bison, prairie dogs, human hunters, and fire created a diversity of large-scale habitats that shifted in space and time (see figure below). Such a shifting mosaic of habitats provided a wider array of habitats than is present now. Certain breeding birds like McCown’s Longspurs and Mountain Plovers prefer heavily grazed areas while Sprague’s Pipits and Baird’s Sparrows favor more lightly grazed grasslands for nesting.
For some birds the entire spectrum is needed during the life cycle: heavily grazed areas of short grass and bare ground may be used as staging areas for mating displays while taller vegetation provides nesting and feeding habitat as well as cover for young birds. Grassland birds require these habitats in relatively large areas; individuals require smaller patches, but many species are more productive at sites where groups of individuals can occur (on the order of 300-500 acres of one habitat type).
Simplified diagram (after Knopf 1996) representing habitats once maintained by interactions between bison, fire, predators, and other grazers. Some species require different habitats across their lifecycles. Fencing and grazing practices have managed to the middle such that the species associated with heavy and little grazing face the greatest shortages in habitats.
1. Threats identified on NPCN interactive map at http://npcn.net/npcnWebmap/index.html:
- Conversion – fragmentation, pesticides
- Oil & Gas – fragmentation and industrial development of otherwise intact grassland
- Wind Development – fragmentation of intact grasslands if inappropriately sited
- Land practices – lack of diverse grazing regimes, lack of fire
- Loss of sagebrush and spread of West Nile Virus by mosquitoes — impacted by climate change
2. U.S. Farm Bill – incentives for landowners that can be bad or good for grasslands (incentives to grow crops can further reduce grassland extent, while incentives to retain native cover can protect a wide array of grassland plants, animals and ecosystem services)
3. Canadian Prairie Farm Rehabilitation Administration (PFRA) lands, similar to U.S. Federal lands abandoned by homesteaders during the Dust Bowl, (in southern Saskatchewan equal 1.6 million acres of native grassland) will no longer be under Federal control and their fate is uncertain. See: http://pfrapastureposts.wordpress.com/
Recently, Canada has further announced intentions to relinquish research stations such as Onefour, home to 23 Canadian listed species at risk. Environmental NGOs are working to secure long-term protection for this site with a focus on species at risk.
4. Industrial development for Oil and Gas production in the Little Missouri National Grassland, and around Theodore Roosevelt National Park, both in North Dakota.
1. The majority of land in the region is privately owned and grazing for cattle production is the dominant use. Several bird species have relatively simple habitat requirements that can be produced through grazing management — and in many cases may represent win-wins for conservation and livestock production.
2. Production of Best Management Practices exist or are being developed for:
- Oil & Gas well & road densities
- Agricultural practices – grazing, fencing, water use
- Restoration – re-seeding, fire, grazing
- BLM Environmental Impact Statement/Resource Management Plan sage grouse revisions
3. Metrics are in development for gauging success
- Birds as indicators of ecosystem health — birds as umbrella species
- Possibilities for understanding benefits for other types of wildlife
4. Political initiatives:
- Neotropical Migratory Bird Conservation Act ($5 million appropriated annually)
- US Fish and Wildlife Service Migratory Bird Treaty Act — mitigation for incidental ‘take’
- Farm Bill: possible inclusion of incentives to promote landowners maintaining grass and removal of crop incentives that encourage the conversion of grasslands
- Canadian PFRA pasture and Onefour Research Station securement
- Possible re-funding of Montana Fish Wildlife and Parks Avian Conservation Biologist position
- Ballot initiative to dedicate tax receipts from Oil/Gas development in North Dakota to conservation, with particular focus on the Little Missouri National Grasslands and Theodore Roosevelt National Park.
|NPCN Priority Bird list:||Habitat in NGP||Status (Canada; US)|
|1. Greater Sage Grouse||Sage brush dependent||End.; ESA candidate|
|2. Burrowing Owl||Burrowing mammal dependent||End.; None|
|3. Mountain Plover||Prairie dog dependent||End.; warranted precluded|
|4. Long-billed Curlew||Native grasses mixed grazing impacts||Sp. Concern; None|
|5. Sprague’s Pipit||Native grasses lightly grazed||Threatened; ESA candidate|
|6. Baird’s Sparrow||Native grasses lightly grazed||COSEWIC Sp Concern|
|7. Chestnut-collared Longspur||Native grasses moderately to heavily grazed||Threatened; None|
|8. Lark Bunting||Mix of shrubs and grass||None; None|
|Discussed but tabled:|
|Grasshopper Sparrow||Native grasses lightly to moderately grazed||None; None|
|McCown’s Longspur||McCown’s Longspur||Sp. Concern; None|