Response of mountain plovers to plague-driven dynamics of black-tailed prairie dog colonies

Authors: Augustine, David; DINSMORE, STEVEN - IOWA STATE UNIVERSITY; WUNDER, MICHAEL - COLORADO STATE UNIVERSITY; DREITZ, VICTORIA - COLORADO DIV. OF WILDLIFE; KNOPF, FRITZ - NONE

Submitted to: Landscape Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/22/2008
Publication Date: 6/27/2008
Citation: Augustine, D.J., Dinsmore, S.J., Wunder, M.B., Dreitz, V., Knopf, F. 2008. Response of mountain plovers to plague-driven dynamics of black-tailed prairie dog colonies. Landscape Ecology 23:689-697.

Interpretive Summary: Sylvatic plague is a major factor influencing prairie dog colony dynamics in the western Great Plains. We studied the nesting response of the mountain plover (Charadrius montanus), a grassland bird that nests on prairie dog colonies, to plague-driven dynamics of prairie dog colonies at three sites in the western Great Plains. First, we examined plover nest distribution on colonies that were previously affected by plague, but that had been recovering (expanding) for at least 6 years. Plovers consistently nested in both young (colonized in the past 1 – 2 years) and old (colonized for 6 or more years) portions of prairie dog colonies in proportion to their availability. Second, we examined changes in plover nest density at two sites following plague epizootics, and found that mountain plover nests declined relatively rapidly on plague-affected colonies, within 1 – 2 years. Taken together, our findings indicate that available plover nesting habitat associated with prairie dog colonies closely tracks the area actively occupied by prairie dogs each year. The scale of plague epizootics varied among our three study sites, with potential implications for the effect of plague on mountain plovers. In two landscapes, plague outbreaks were localized, such that the mean distance from plague-affected colonies to non-affected colonies was 3.5 – 7.2 km. These conditions may afford opportunity for plovers to shift nest sites among years to active and expanding colonies. In a third landscape, plague affected a large (>100,000 ha) area in a single year, with a mean distance of 19.2 km from plague-affected to non-affected colonies. In such a landscape, the sustainability of mountain plover populations may depend upon availability and quality of alternate nesting habitat.

Technical Abstract: Sylvatic plague is a major factor influencing prairie dog colony dynamics in the western Great Plains. We studied the nesting response of the mountain plover (Charadrius montanus), a grassland bird that nests on prairie dog colonies, to plague-driven dynamics of prairie dog colonies at three sites in the western Great Plains. First, we examined plover nest distribution on colonies that were previously affected by plague, but that had been recovering (expanding) for at least 6 years. Plovers consistently nested in both young (colonized in the past 1 – 2 years) and old (colonized for 6 or more years) portions of prairie dog colonies in proportion to their availability. Second, we examined changes in plover nest density at two sites following plague epizootics, and found that mountain plover nests declined relatively rapidly on plague-affected colonies, within 1 – 2 years. Taken together, our findings indicate that available plover nesting habitat associated with prairie dog colonies closely tracks the area actively occupied by prairie dogs each year. The scale of plague epizootics varied among our three study sites, with potential implications for the effect of plague on mountain plovers. In two landscapes, plague outbreaks were localized, such that the mean distance from plague-affected colonies to non-affected colonies was 3.5 – 7.2 km. These conditions may afford opportunity for plovers to shift nest sites among years to active and expanding colonies. In a third landscape, plague affected a large (>100,000 ha) area in a single year, with a mean distance of 19.2 km from plague-affected to non-affected colonies. In such a landscape, the sustainability of mountain plover populations may depend upon availability and quality of alternate nesting habitat.