Northern bobwhites thrive in fine-grained landscapes with a diversity of early succession woodland, grassland, and agriculture-associated habitat types. Bobwhite conservation has proved challenging in the increasingly coarse-grained Midwestern landscape as simplified agricultural cropping systems are implemented at larger spatial scales. Regardless, managing agricultural landscapes on private lands is the primary opportunity to restore bobwhite populations in the Midwestern United States. Although bobwhite habitat requirements are well understood, habitat selection in contemporary Midwestern landscapes is not well understood, especially on private lands where populations are declining. We used compositional analysis to investigate second-(study area) and third-(home range) order habitat selection by radiomarked bobwhite coveys on 4 private land study areas in southwestern Ohio. Mean covey home range size was 26.1 AE 2.2 ha (n ¼ 48). Although home ranges were established in areas with more grassland cover, bobwhites most strongly selected early succession woody habitat (e.g., fencerows and ditches) at all scales, and selection for grassland diminished between the study area and home range scales. Grassland selection varied among sites and was strongest on sites with more row crop area. Woodlots were avoided at the study area scale, but were selected within home ranges. Grassland cover, like that provided by contemporary conservation programs, is an essential component of bobwhite habitat in the Midwest, but our results suggest more emphasis should be placed on early succession woody cover. Woody cover associated with fencerows, ditches, and woodlots adjacent to food sources and breeding habitat will likely improve non-breeding season survival, which is an influential vital rate in northern populations. ß 2012 The Wildlife Society.KEY WORDS agricultural landscape, Colinus virginianus, compositional analysis, northern bobwhite, Ohio, private land, woody cover.

Habitat quality influences individual survival at widely varying spatial and temporal scales. Understanding interactions between habitat and survival among individuals in declining populations that occupy highly modified landscapes can inform conservation strategies aimed at improving survival and population growth. We used radiotelemetry to monitor space use and daily survival of wintering Northern Bobwhites (Colinus virginianus) at the northern end of their range to test for fine spatial-and temporal-scale relationships between individual survival and habitat composition around radio-locations in agricultural landscapes in Ohio, USA. Habitat composition within daily and seasonal movement ranges of individuals (n ¼ 189) during periods without snow cover did not explain variation in daily survival rates. However, mortality increased substantially in the presence of snow cover, and availability of woody cover and row crops within 95 m of an individual radio-location were positively associated with daily survival during those periods. A similar relationship between row crop availability and survival was supported at a larger scale that reflected composition of seasonal ranges (300-m buffer) but was less influential than fine-scale influences of woody cover and row crops. Our results suggest that previously documented selection for woody cover in our agricultural study areas was an adaptive behavior to improve individual survival during periods of snow cover. Positive associations between survival and row crop cover at daily and seasonal range scales suggest that agricultural landscapes confer improved survival probabilities when underlying constraints on occupancy related to woody cover are met. Collectively, our results suggest that targeted conservation practices focused on provision of suitable woody cover in agricultural landscapes in the northern end of the Northern Bobwhite's range has potential to improve winter survival and perhaps abate long-term population declines in the region.El há bitat influencia la supervivencia de Colinus virginianus a escalas espaciotemporales finas RESUMEN La calidad del hábitat influencia la supervivencia de los individuos a escalas espaciales y temporales muy diversas. Entender las interacciones entre el hábitat y la supervivencia de individuos de poblaciones en disminución que ocupan paisajes muy modificados puede aportar a las estrategias de conservación que buscan aumentar la supervivencia y el crecimiento poblacional. Empleamos radio telemetría para monitorear el uso del espacio y la supervivencia diaria de individuos invernantes de Colinus virginianus en el extremo norte de su rango, y evaluamos las relaciones espaciales y temporales a escala fina entre la supervivencia individual y la composición del hábitat alrededor de las localizaciones de radio en paisajes agrícolas en Ohio. La composición del hábitat dentro de los rangos de movimiento diarios y estacionales de los individuos (n ¼ 189) durante períodos sin cobertura de nieve no explicaron la variación en las tasas de ...

The Prairie Pothole Region (PPR) of north‐central United States and south‐central Canada supports greater than half of all breeding mallards (Anas platyrhynchos) annually counted in North America and is the focus of widespread conservation and research efforts. Allocation of conservation resources for this socioeconomically important population would benefit from an understanding of the nature of spatiotemporal variation in distribution of breeding mallards throughout the 850,000 km2 landscape. We used mallard counts from the Waterfowl Breeding Population and Habitat Survey to test for spatial heterogeneity and identify high‐ and low‐abundance regions of breeding mallards over a 50‐year time series. We found strong annual spatial heterogeneity in all years: 90% of mallards counted annually were on an average of only 15% of surveyed segments. Using a local indicator of spatial autocorrelation, we found a relatively static distribution of low‐count clusters in northern Montana, USA, and southern Alberta, Canada, and a dynamic distribution of high‐count clusters throughout the study period. Distribution of high‐count clusters shifted southeast from northwestern portions of the PPR in Alberta and western Saskatchewan, Canada, to North and South Dakota, USA, during the latter half of the study period. This spatial redistribution of core mallard breeding populations was likely driven by interactions between environmental variation that created favorable hydrological conditions for wetlands in the eastern PPR and dynamic land‐use patterns related to upland cropping practices and government land‐retirement programs. Our results highlight an opportunity for prioritizing relatively small regions within the PPR for allocation of wetland and grassland conservation for mallard populations. However, the extensive spatial heterogeneity in core distributions over our study period suggests such spatial prioritization will have to overcome challenges presented by dynamic land‐use and climate patterns in the region, and thus merits additional monitoring and empirical research to anticipate future population distribution. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Increasing global demands for land to produce food, fiber, and energy threatens temperate grassland and wetland ecosystems, catalyzing a need to inform strategic and efficient approaches to conserve ecological function in these ecosystems. In the Prairie Pothole Region of North America, an extensive agricultural footprint has grown since the late 19th century and recently expanded in extent and intensity of cultivation in response to improved technology and global demands. Despite extensive modifications, many wetlands remain in a matrix of intensively farmed uplands in this landscape. We comprehensively evaluated contributions of those wetlands to spring-migrating ducks by studying two wetland-obligate foragers-lesser scaup (Aythya affinis) and bluewinged teal (Anas discors)-as they migrated to northern breeding ranges. We measured a comprehensive suite of physiological, ecological, and behavioral metrics important during migration in wetlands across a range of upland cultivation intensities at fine and coarse spatial extents. We found no systematic negative responses in invertebrate prey abundance, abundance of migrants, or lipid metabolism of migrant females across the cultivation intensity gradient. Further, abundance and physiology of blue-winged teal and some key invertebrate prey densities were higher in more intensively cultivated landscapes. Our results demonstrated extant wetlands in modern, intensively farmed landscapes make meaningful contributions to spring-migrating ducks despite likely negative impacts of proximate upland cultivation. This insight raises questions about the consequences of agricultural perturbations and the baseline functionality of wetlands in agriculturally productive landscapes that have implications for wetland restoration and conservation strategies employed here and in intensively farmed landscapes globally.

Relationships between northern bobwhite (Colinus virginianus) population dynamics and weather are well‐established and managed in the southern and western core of their range. Although a qualitative recognition of effects of winter weather at the northern edge of the northern bobwhite range exists, quantitative evaluations that examine impacts of severe winter weather events on declining northern populations are lacking. We used radiotelemetry to evaluate relationships between daily survival and winter weather in 2 northern populations in Maryland and Ohio, USA. Ninety‐day winter (Dec–Feb) survival varied with total snow accumulation among years and sites, with lowest survival (0.007, SE = 0.007) occurring during greatest snow accumulation and highest survival (0.498, SE = 0.088) during the mildest winter. Snow depths were negatively associated with daily survival in Ohio and Maryland, whereas association with temperature was marginal and differed among sites and years. We used northern bobwhite counts from the North American Breeding Bird Survey (NABBS) to test whether local effects of snow accumulation on winter survival manifest in population reductions up to 5 years following locally extreme snow accumulation events on 128 routes in the northern bobwhite range. Our best‐supported linear mixed model showed snow accumulation during 4 preceding winters was associated with population declines, with declining associations between abundance and snow accumulation over longer time lags. Our NABBS analysis linked local demographic effects from the radiotelemetry study to population‐level changes in abundance at a wide geographic scale, collectively illustrating the capacity for comparatively rare but severe winter weather events to produce a legacy of population change among northern populations. Conservation strategies for these populations should take into account the potential effect of severe winter weather on population stability and seek to employ conservation measures that increase resiliency to severe winter weather events. © 2017 The Wildlife Society.