Regional estimates of duck brood abundance could help conservation managers assess landscape productivity and thereby improve spatially explicit allocation of limited conservation funds in the Prairie Pothole Region. We assessed the utility of repeat-visit brood counts from 2012 to 2013 surveys in the Prairie Pothole Region (ND, SD, and MT, USA) and hierarchical N-mixture models for providing estimates of abundance at a 10.4-km 2 scale. Models provided reliable estimates of brood abundance and underscored the importance of small wetlands and landscape characteristics to some dabbling duck broods in the Prairie Pothole Region. Ó

Conservation of wildlife depends on an understanding of the interactions between animal movements and key landscape factors. Habitat requirements of wide-ranging species often vary spatially, but quantitative assessment of variation among replicated studies at multiple sites is rare. We investigated patterns of space use for 10 populations of two closely related species of prairie grouse: Greater Prairie-Chickens (Tympanuchus cupido) and Lesser Prairie-Chickens (T. pallidicinctus). Prairie chickens require large, intact tracts of native grasslands, and are umbrella species for conservation of prairie ecosystems in North America. We used resource utilization functions to investigate space use by female prairie chickens during the 6-month breeding season from March through August in relation to lek sites, habitat conditions, and anthropogenic development. Our analysis included data from 382 radio-marked individuals across a major portion of the extant range. Our project is a unique opportunity to study comparative space use of prairie chickens, and we employed standardized methods that facilitated direct comparisons across an ecological gradient of study sites. Median home range size of females varied ;10-fold across 10 sites (3.6-36.7 km 2 ), and home ranges tended to be larger at sites with higher annual precipitation. Proximity to lek sites was a strong and consistent predictor of space use for female prairie chickens at all 10 sites. The relative importance of other predictors of space use varied among sites, indicating that generalized habitat management guidelines may not be appropriate for these two species. Prairie chickens actively selected for prairie habitats, even at sites where ;90% of the land cover within the study area was prairie. A majority of the females monitored in our study (.95%) had activity centers within 5 km of leks, suggesting that conservation efforts can be effectively concentrated near active lek sites. Our data on female space use suggest that lek surveys of male prairie chickens can indirectly assess habitat suitability for females during the breeding season. Lek monitoring and surveys for new leks provide information on population trends, but can also guide management actions aimed at improving nesting and brood-rearing habitats.v www.esajournals.org 1 September 2015 v Volume 6(9) v Article 166

No abstract

Radiotransmitters can be tail-mounted using cyanoacrylate glue and an accelerant rather than using a harness. Tail-mounted transmitters are dropped or shed when the rectrices molt, which may reduce transmitter effects while providing retention times sufficient for most research objectives. However, retention times of tail-mounted transmitters for birds are insufficiently described, and bias from not following all birds until transmitters are shed has been ignored. We studied transmitter retention of 106 birds of 6 species in the United States of America, 2010-2013, using direct observations and survival modeling based on radiotelemetry tracking. Cox proportional hazard survival models predicted median transmitter retention times from 4 to 53 days, depending on species. Our results suggest that researchers should anticipate premature (i.e., <30 days) tag loss rates from 15% to 38% for adult birds, and adjust permit and funding applications accordingly. However, predicted premature tag loss approached 100% for independent juvenile birds, which frequently appeared to disperse long distances, leading to few or no failure events to inform models. Overall, our results provide guidance for the design of future telemetry studies while demonstrating that tail-mounting transmitters can yield adequate data for a variety of research objectives. Ó