Relationship between shrubs and foods in mountain plover habitat in Park County, Colorado

We explored habitat use in terms of vegetation structure and potential forage availability for mountain plovers (Charadrius montanus) in Park County, Colorado. We quantified the percentage cover of bare ground, percentage cover of shrubs (Chrysothamnus visadiflorus), linear distance to nearest shrub, arthropod biomass, and grasshopper density for 102 plots of 1,963 m2, 51 of which were occupied by plovers and 51 of which were selected randomly within previously-classified potential habitat. We modeled the probability of habitat use by plovers based on these measurements. We further subdivided the occupied plots to model probability of habitat use by adults with broods as compared with use by pre-nesting and post-nesting adults. Percentage of bare ground and probability of habitat use for adults with broods were related inversely, but not so for adults without broods. Grasshopper density was positively related to probability of habitat use by adults without broods, whereas proximity to nearest shrub was negatively related. We propose that habitat use by plovers in South Park is influenced by the amount of available shrub-grassland edge habitat and the availability of forage.