Verheigen, B.H.F., R.T. Plumb, C.K.J. Gulick, C.A. Hagen, S.G. Robinson, D.S. Sullins, and D.A. Haukos. 2021. Breeding season space use by lesser prairie-chickens (Tympanuchus pallidicinctus) varies among ecoregions and breeding stages. American Midland Naturalist 185:149-174.
Large-scale declines of grasslands ecosystems in the conterminous United States since European settlement have led to substantial loss and fragmentation of lesser prairie-chicken (Tympanuchus pallidicinctus) habitat and decreased their occupied range and population numbers by ~85%. Breeding season space use is an important component of lesser prairie-chicken conservation, because it could affect both dynamics and carrying capacity of local populations. Previous estimates of breeding season space use are largely limited to one of the four currently occupied ecoregions, but potential extrinsic drivers of breeding space use, such as landscape fragmentation, vegetative structure and composition, and density of anthropogenic structures, can show large spatial variation. Moreover, habitat needs vary greatly among the lekking/prelaying, nesting, brooding, and postbreeding stages of the breeding season, but space use by female lesser prairie-chickens during these stages remain relatively unclear. We tested whether home range area and daily displacement of female lesser prairie-chickens varied among ecoregions and breeding stages at four study sites in Kansas and Colorado, USA, representing three of the four currently occupied ecoregions. We equipped females with very-high-frequency (VHF, n = 39) or GPS transmitters (n = 157), and estimated home range area with kernel density estimators or biased random bridge models, respectively. Across all ecoregions, breeding season home range area averaged 190.4 ha (± 19.1 ha SE) for birds with VHF and 283.6 ha (± 23.1 ha) for birds with GPS transmitters, while daily displacement averaged 374.8 m (± 14.3 m). Average home range area and daily displacement were greater in the Short-Grass Prairie/CRP Mosaic Ecoregion (VHF: 233.0 ± 34.7 ha, GPS: 420.8 ± 52.8 ha, 468.5 ± 29.4 m) compared to sites in the Mixed-Grass Prairie Ecoregion (VHF: 146.4 ± 16.4, 158.6 ± 25.2 ha, GPS: 183.9 ± 21.2, 183.3 ± 13.9 ha, 281.0 ± 16.0, 319.5 ± 13.8 m). Home range area and daily displacement were greatest during lekking/prelaying (252.8 ± 23.0 ha, 539.7 ± 223.0 m) and smallest during the brooding stage (81.4 ± 11.5 ha, 221.3 ± 63.7 m), when female movements are restricted by mobility of chicks. Ecoregion- and breeding stage-specific estimates of space use by lesser prairie-chickens will help managers determine the spatial configuration of breeding stage-specific habitat on the landscape. Furthermore, ecoregion- and breeding stage specific estimates are crucial when estimating the amount of breeding habitat needed for lesser prairie-chicken population to persist.