Habitat Selection by Chestnut-Cheeked Starling During the Breeding Season in the Northern Tohoku Region

Contemporary landscape change driven by socio-economic forces and advances in agricultural technology do not favor northern bobwhites (Colinus virginianus) in the Midwestern United States. The challenge of bobwhite conservation is to provide sufficient quantities of habitat with optimal configurations in proportions that satisfy needs throughout the year on private-owned working lands. We radio-tracked 58 coveys and 98 individual birds throughout the year in 2009-10 and 2010-11 on privately owned farmland in southwestern Ohio. We investigated temporal changes in usable space from use-availability data. Estimated proportions of usable space based on analyses of habitat selection across four study sites were 0.06-0.12 during the non-breeding season compared to 0.10-10.30 during the breeding season. We also modeled probabilities that radio-marked coveys or individual birds used points within individual cover types as a function of distance to other cover types. Locations of radio-marked coveys and individual birds within focal cover types were closer to other cover types compared to random points during breeding (mean = 44 m) and non-breeding (mean = 58 m) seasons. Probability of use within focal cover types declined with distance to other cover types, typically falling below 50% when distances exceeded 9-242 m. Locations of radio-marked coveys were concentrated near edges within used cover types, while locations of individual birds were more dispersed during the breeding season. Estimated proportions of usable space based on distances between locations of radio-marked bobwhites and nearest cover types were higher (0.30-0.53) than estimates based on habitat selection ratios, and were similar between non-breeding and breeding seasons. Potentially usable sites were not fully occupied in either season, but there was no relationship between crude covey densities and proportions of usable space estimated from habitat selection analyses during the breeding and non-breeding seasons across study sites and years (r2 < 0.166, P > 0.316). With distance to cover type estimates of usable space (years combined), two study sites with the highest proportions of usable space (0.43-0.53) also had the largest crude covey densities (0.0065-0.153 coveys/ha) compared to the other two sites with lower proportions of usable space (0.30-0.32) and smaller covey densities (0.004 – 0.006 coveys/ha). Habitat enhancement should focus on providing protective cover near food for coveys during the non-breeding season and protective cover near nesting and brood-rearing habitat during the breeding season. Conserving Midwestern bobwhite populations requires innovative practices that can be implemented on private lands as economic incentives change for farm operators. Improving protective cover along habitat edges can increase usable space by improving cover type juxtaposition (e.g. food near cover) while minimizing impact on farming practices.

Environmental factors strongly affect mangrove crabs, and some factors modulate population structure and habitat partitioning during the crabs’ life cycle. However, the effect of these environmental factors on habitat selection by mangrove crabs is still unknown. We evaluated habitat selection by the mangrove crab Ucides cordatus in mangrove forests with different degrees of predominance of Rhizophora mangle, Laguncularia racemosa or Avicennia schaueriana, two tidal flooding levels (less- and more-flooded), and two biological periods (breeding and non-breeding seasons). Sampling was conducted in four mangrove forests with different influences of these biotic and abiotic parameters. We used the data for sex ratio to explain environmental partitioning by this species. Females predominated in R. mangle mangroves, independently of the biological period (breeding or non-breeding seasons), and males predominated only in the less-flooded L. racemosa mangroves. The flooding level affected the sex ratio of U. cordatus, with a predominance of males in less-flooded mangroves, independently of the biological period; and a gender balance in the more-flooded mangroves only during the breeding season. Outside the breeding season, the largest specimens were recorded in the R. mangle mangroves, but in the breeding season, the largest crabs were recorded in the L. racemosa mangroves with a higher level of flooding. These results suggest that tree-species composition and tidal flooding level can have a significant effect on the habitat partitioning of sexes and sizes of the mangrove crab U. cordatus both during and outside the breeding season.

There is growing recognition of the need to conserve areas used by birds during migration, including forest and upland habitats. Because extensive thinning and burning treatments are planned for ponderosa pine (Pinus ponderosa) forests in the southwestern United States, information on the use of these forests by landbirds during migration is needed for conservation planning. We compared species richness among spring, breeding, and fall seasons at 69 points in a ponderosa pine forest to assess changes in landbird communities and the role of different ponderosa pine cover types in habitat selection among seasons. We detected a total of 64 bird species. Bird community similarity was lowest between the breeding and fall seasons and highest between the spring and breeding seasons. Twenty percent of the species detected were present exclusively in the fall and, of these, over half were Neotropical migrants. Only two species (3%) were detected exclusively during the spring. Although we found little difference in bird species similarity among vegetative cover types during the breeding season, forests that contained a deciduous component exhibited higher bird species similarity with each other than with habitats that did not include a deciduous component in spring and fall. In addition, foliage foragers dominated the community in spring and fall, and all Neotropical migrants detected exclusively in fall were found in ponderosa pine forests with a deciduous component. Our results indicate that ponderosa pine forests may be important to migrating or dispersing landbirds in autumn, especially if there is a deciduous component.

Maladaptive habitat selection, where animals select habitat with reduced fitness potential or avoid otherwise suitable habitat, exacerbates the threat of population decline for species vulnerable from habitat loss and fragmentation. The greater sage‐grouse (Centrocercus urophasianus) is a species of conservation concern for which research has identified scenarios where populations may be under the influence of maladaptive habitat selection. Our objective was to evaluate whether sage‐grouse selected habitat relative to habitat quality (i.e., ability to provide for higher survival or reproductive success), and to identify any habitat characteristics where they were not matching selection with costs and benefits, during the nesting, brood rearing, adult breeding, adult summer, and adult winter seasons. We measured an overall apparent adaptive relationship between habitat selection and survival for brood, adult breeding, and adult winter habitat. There was an overall apparent maladaptive relationship for nest and adult summer survival. Of 25 specific habitat characteristics that influenced sage‐grouse reproductive success or survival, 13 (52%) had an apparent adaptive selection relationship, 10 (40%) had an apparent maladaptive relationship, and 2 (8%) were either inconclusive or not strongly selected. Surprisingly, most (8 of 10) of the habitat characteristics we observed that were selected contrary to apparent costs or benefits were associated with environmental variables (i.e., topography and vegetation). Relative to possible maladaptive selection and anthropogenic disturbance, grouse selected for areas of higher mortality risk near minor roads during the breeding season and grouse did not select for non‐irrigated agricultural disturbance which had lower mortality risk. However, after accounting for the effects of habitat selection on all demographic rates that determine fitness, these apparent maladaptive selection effects were probably not biologically significant. The strongest evidence we observed for maladaptive habitat selection associated with anthropogenic land use was during summer when grouse were selecting for the edge of irrigated hayfields where there was higher mortality risk. To ensure the success of sage‐grouse conservation actions, we encourage further investigation identifying the mechanisms behind observed cases of apparent maladaptive selection or identifying any fitness benefits that grouse are gaining from selecting risky areas.

Social prey species respond to predation risk by modifying habitat selection and grouping behaviour. These responses may depend on both actual predation risk (predator probability of occurrence) and/or on perceived predation risk associated with habitat structure. Other factors like food availability and co‐occurrence with other species may also affect habitat selection and group formation. We analyse habitat selection and grouping behaviour (group size and cohesion) of lesser rhea (Rhea pennatasubsp.pennata), a ratite endemic of South America inhabiting steppe shrublands and grasslands, in relation to actual (puma probability of occurrence) and perceived (habitat structure: openness, visibility) predation risk, co‐occurrence with other herbivore species and forage availability in the Chilean Patagonia. We used data from 9 sampling seasons in 5 years. Results show that habitat selection, group size and cohesion in lesser rhea were mainly driven by variables associated with perceived predation risk and by co‐occurrence with other herbivores both during breeding and non–breeding season. As expected, lesser rhea preferred open habitats (vegas and grasslands) that allow a behaviour of ‘watch and run’ to avoid predation and formed larger groups in them. Moreover, lesser rhea positively selected year‐round habitats where livestock occur, forming large groups during non–breeding season there. Group size and co‐occurrence with other herbivores significantly decreased group cohesion, suggesting a reduction of perceived predation risk. Therefore, lesser rhea seems to take advantage of forming mixed interspecific groups to reduce predation risk. These results suggest that lesser rhea habitat selection and grouping behaviour are preferentially driven by factors related to perceived predation risk than by actual predator occurrence or food availability.

Wild turkey (Meleagris gallopavo) males were captured and radio-tagged in a bottomland hardwood forest of south-central Louisiana. Turkeys were monitored year round from fixed telemetry stations on Sherburne Wildlife Management Area, Atchafalaya National Wildlife Refuge, and Bayou des Ourses to observe seasonal patterns of space use, habitat selection and survival from 2005-07. The largest seasonal home range was in fall/winter (966.41 ha; Oct 1-Feb 28). Spring home range (767.77 ha; Mar 1- May 31) size was lower than reported in previous studies and was a function of female availability. Season and age interacted to influence core area size (F5/63 = 2.35, P = 0.051), but not home range size (F5/63 = 1.49, P = 0.207). Males did not move about their home range differently before or during the breeding season (t20 = 1.11, P = 0.282). Additionally, males did not display spatial shifts of core areas before and during the breeding season at the population level (t20 = -0.92, P = 0.367). Upland forests and water-based forests were selected by adults and juveniles at all 3 spatial scales (habitat selection in home ranges vs. habitat availability across study area [1st order], habitat selection in core areas vs. habitat availability across home ranges [2nd order], and habitat availability across home ranges [3rd order]), whereas lowland forests were avoided at all 3 spatial scales. Habitat selection in spring was based on location of females. Water-based forests were essential to male habitat as they provide quality roosting and feeding sites. Survival was lowest in spring (0.43, SE = 0.09; Mar 1- May 31) due to the spring harvest. Fall/winter survival averaged 0.74 (SE = 0.05; Oct 1-Feb 28) and survival during summer averaged 0.74 (SE=0.06; Jun 1-Sept 30). Mean annual survival was 0.64 (SE = 0.06), among the highest ever reported for wild turkey males. The conservative harvest strategy on Sherburne was likely related to high survival rates for males

Deciphering how environmental heterogeneity affects population dynamics in migratory species is complicated by the redistribution of individuals in time and space across the annual cycle. Approaches that tackle this problem require information about how migratory species respond to ecological factors across time and space, and how they are linked across migratory periods. Using high spatial resolution (10 m) GPS tracking of individual male songbirds, we quantified for the first time (1) local‐ and landscape‐scale habitat selection across the annual cycle and (2) patterns indicative of regional habitat selection for individuals within five populations of wood thrush (Hylocichla mustelina) throughout their breeding range. Wood thrush exhibited seasonal variation in local‐ and landscape‐scale habitat selection. Within stationary periods, wood thrush occupied forested habitats and proximity to forest edge was an important predictor of habitat selection at the local scale. In contrast, during migratory periods wood thrush exhibited greater behavioral flexibility indicative of a more generalist approach to habitat selection. Landscape habitat selection was only identified during the breeding season (average patch size) and could be a response to the extensive forest fragmentation in the North American breeding grounds. We also identified individual population distribution patterns indicative of regional habitat selection during fall migration and winter period, but not spring migration. Seasonal changes in habitat selection at multiple spatial scales suggest the factors driving habitat selection patterns are aligned with life‐history stage and may be dependent on regional differences in landscape composition. These results highlight the importance of a full annual cycle approach to ecological studies that address how migratory species respond to spatial and temporal environmental heterogeneity.

Habitat quality and availability are crucial for the survival and reproduction of animal species. Intraspecific and seasonal differences in habitat selection reflect adaptations to changing biological requirements and environmental factors. To investigate the effects of season (breeding and non-breeding) and sex on microhabitat selection in snakes, here we employed field surveys to analyze microhabitat selection data for Stejneger's bamboo pitviper (Viridovipera stejnegeri) across different sexes and seasons. Results indicated that although no significant difference was observed between groups, marked differences in certain microhabitat factors were noted. Specifically: (1) Non-breeding season females (NBF) displayed distinct differences in altitude, slope position, distance from roads compared to other groups. (2) Temperature exerted a lesser effect on non-breeding season individuals compared to breeding season individuals. Additionally, distance from roads only significantly impacted breeding season males, not females. (3) Regarding sexual differences, males and females differed in slope position and distance from residential sites, reflecting their distinct ecological requirements. Regarding seasons, differences in habitat selection between breeding and non-breeding seasons were primarily related to temperature, indicating behavioral changes linked to seasons. (4) Non-breeding season females exhibited the narrowest microhabitat niche width and the least microhabitat niche overlap with other groups, potentially due to their pronounced foraging requirements, which compel them to explore limited habitats with higher human disturbance but richer food sources. This study contributes novel insights into the habitat selection behaviors of snakes.

Seasonal habitat use and breeding performance of the Eurasian Skylark (Alauda arvensis) in Central European farmland

Agri-environment schemes (AES), as part of the European Union's Common Agricultural Policy, are intended to help prevent the decline of farmland biodiversity. Nevertheless, the ecological effectiveness of AES in supporting farmland bird populations remains inconclusive across studies. This inconsistency highlights a research gap: What behavioral mechanisms contribute to the variation in farmland bird populations? This variability may arise because farmland birds alter their habitat selection in response to available habitat—a phenomenon known as functional responses in habitat selection. Here, we examined the effects of AES and non-AES land-use variables on habitat selection of farmland birds, taking into account the species-specific functional response to availability. We built two types of hierarchical distance sampling models to analyze observational data of four farmland bird species from line-transect surveys during the breeding season in Saxony, Germany. First, we built mixed-effects models to estimate the marginal effects of AES and non-AES land-use variables on the occurrence of farmland birds. Second, we integrated linear models into the distance sampling model to relate habitat selection estimates to habitat availability. Results from the first mixed-effects model showed positive and negative effects of AES on habitat selection. In the second model, we observed inverse relationships between habitat selection and availability for both AES and non-AES variables. These results support the hypothesis of negative functional responses, as we found a decrease in the tendency of farmland birds to select both AES and non-AES land uses as their availability increased. Our findings suggest that the varying effects of AES on bird occurrences reported in the literature may depend on cross-study differences in AES availability. We propose that functional responses in habitat selection should be considered as a phenomenon in future AES research. Our study also highlights the importance of optimal AES provision and their spatial allocation in the agricultural landscape.

Habitat Selection of Female Rio Grande Wild Turkey Influenced by Vegetation and Anthropogenic Structures

We investigated habitat selection patterns of the great bustard Otis tarda in a dynamic agricultural landscape in southern Portugal. Combining data from 26 bustard counts with habitat mapping, we used resource selection functions to characterise habitat selection in two areas with different agricultural uses. Selection patterns were compared among areas, seasons (breeding, post‐breeding and winter), and flock types (male, female and mixed) during the breeding season. Seasonal differences in selection patterns generally parallelled changes in estimated food availability. Stubbles (i.e. recently harvested fields) and stream margins were preferentially selected by all bustards during the post‐breeding period, whereas cereal and fallow fields were selected during winter. During the breeding season, males selected fallow fields more than other habitat types, whereas females selected cereal fields. Habitat selection seemed to be influenced by habitat availability, with birds showing stronger selection for preferred habitats in the areas where they were less available. Great bustards used different habitat types throughout the agricultural year, and we recommend that habitat management promotes a rotational crop system that includes cereal and fallow fields.

Understanding the rules of habitat selection and the individual behavioural routines in the home‐range is crucial for developing evidence‐based conservation action. We investigated habitat selection and range use of adult little owls Athene noctua in relation to landscape configuration, habitat structure and resource distribution. We determined the preference of habitat structures by VHF‐telemetry. Large‐ and fine‐scale distribution patterns of voles – the main prey during the breeding season – were assessed by transect counts of signs of vole presence. An experiment using artificial perches was carried out to determine the fine‐scale adjustment of the owls' range use in relation to prey abundance and vegetation height. Habitat selection and resource exploitation by little owls were structured at all spatial levels: (1) at the landscape scale, orchards were highly preferred over other areas. This accords with the patchy large‐scale occurrence of voles, which were absent in cropland, but abundant in orchards and grassland; (2) within home‐ranges, the spatial distribution of voles was highly inhomogeneous and structures with high prey abundance were used over‐proportionally; (3) at the scale of foraging sites, little owls preferred patches with low vegetation over those with high prey abundance, establishing that prey availability is the crux. The results suggest that all levels of habitat selection and range use were related to farming practices and affected by current cultivation. Conservation measures should focus on the conservation and restoration of orchards on the landscape level and habitat management measures should focus on grasslands – the main food providers – by creating a mosaic of patches with short grass and tall grass. Together with other habitat structures providing food resources such as field edges, wildflower areas and structures facilitating access to prey, the quality of habitat patches in terms of food availability may be highly improved.

繁殖期黄喉雉鹑在景观尺度上的生境选择

Both abiotic factors and behavioral patterns may influence snake activity. However, other than reproductive activities, behavioral patterns have rarely been incorporated into studies of snake habitat selection. We investigated seasonal differences in canebrake rattlesnake (Crotalus horridus) movement patterns and habitat selection. We modeled habitat selection in two ways, with and without regard to behaviorally-based seasons, and compared the two models to determine which yielded the most informative results. Behaviorally-based seasons (foraging, breeding, and hibernation) were determined from field observations of study animals. Habitat selection was modeled as habitat use versus availability using a case control sampling design for males and nongravid females using logistic regression. Males had significantly larger home ranges, moved more often, and traveled greater distances between successive locations during the breeding season as compared to nongravid females. The male no-season habitat model lacked significance, and the nongravid female no-season model revealed a positive association with pine savannas. When behaviorally-based seasons were included in the models, both sexes showed distinct seasonal variation in habitat selection, with males and nongravid females using similar habitat for breeding and hibernation, but partitioning habitat during the foraging season. Our results indicate that behaviorally-based seasons provide important details about intraspecific canebrake rattlesnake habitat selection and movement patterns, and that future research should benefit from the inclusion of snake behavior in habitat studies.