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Climate and land-use change have led to disturbance regimes in many ecosystems without a historical analog, leading to uncertainty about how species adapted to past conditions will respond to novel post-disturbance landscapes. We examined habitat selection by spotted owls in a post-fire landscape. We tested whether selection or avoidance of severely burned areas could be explained by patch size or configuration, and whether variation in selection among individuals could be explained by differences in habitat availability. We applied mixed-effects models to GPS data from 20 spotted owls in the Sierra Nevada, California, USA, with individual owls occupying home ranges spanning a broad range of post-fire conditions after the 2014 King Fire. Individual spotted owls whose home ranges experienced less severe fire ( 100-m into severe fire patches. Spotted owls avoided areas that had experienced post-fire salvage logging but the interpretation of this effect was nuanced. Owls also avoided areas that were classified as open and/or young forest prior to the fire. Our results support the hypothesis that spotted owls are adapted to historical fire regimes characterized by small severe fire patches in this region. Shifts in disturbance regimes that produce novel landscape patterns characterized by large, homogeneous patches of high-severity fire may negatively affect this species.

SummaryThe scope and scale of wildlife crimes around the world have risen in intensity and complexity, yet current enforcement strategies have often not delivered desired effects on illegal activities, even within protected areas. Tackling the array of illegal activities by emphasizing law enforcement above other options is challenging and potentially unsustainable. We explored the potential for social norms, community regulations and socioeconomic factors to promote compliance with wildlife laws by interviewing 334 respondents in 28 villages that share boundaries with protected areas in Nigeria. Using an anonymous direct questioning approach, we recorded a high prevalence of non-compliance behaviours in all studied communities. Injunctive norms (i.e., perceptions of acceptable behaviour within a social group) significantly predicted compliance, as respondents with no complicit friends or family members were more likely to comply with wildlife regulations. Perceived likelihood of community-level sanctions played a more salient role than the fear of arrest by rangers in influencing compliance. In addition, non-compliance increased with number of dependents, but reduced with average monthly household income. Our study demonstrates that clear knowledge of the social norms that drive local behaviour as well as the authorities that enforce them is integral to understanding the forces that drive community involvement and participation in conservation. Incorporating local communities in planning enforcement interventions may help protect threatened species and landscapes.

The relative contribution of private and public forest to the conservation of species in mixed-ownership landscapes has often been contentious because management goals vary among owners. This tension can be exacerbated by a lack of understanding about how wildlife use habitats managed by different landowners and the relative value of habitats in having different structures, configurations, and management histories. To address this knowledge gap and enhance science-based conservation planning among different ownerships, we analyzed habitat selection by 53 GPS-tagged California spotted owls across multiple temporal scales within mixed-ownership landscapes in the Sierra Nevada. At a fine temporal scale, step-selection function analysis of hourly locations collected by GPS tags suggested that foraging spotted owls selected closed-canopy, larger-tree forest (Quadratic Mean Diameter [QMD] ≥ 33 cm, canopy cover ≥ 60%). Point selection function (PSF) analysis based on single nightly locations suggested that spotted owls selected a broader range of forest conditions including selection of forests having intermediate sized trees and intermediate canopy cover (QMD 28–33 cm, canopy cover ≥ 50%), and the strength of selection for these forest conditions increased in the less frequently used areas of home ranges. The PSF also suggested that spotted owls selected areas with relatively high cover type heterogeneity that included a mix of seral stages, except in the core of their home range where they selected relatively spatially homogenous forests characterized by large trees and closed canopy. Spotted owl home ranges increased in size with increasing elevation and cover type heterogeneity, and decreased in size with forest characterized by intermediate-sized trees. Collectively, these results indicate that landscapes having forest patches characterized by either intermediate or large-sized trees, both with high canopy cover, likely constitute the important foraging habitat for California spotted owls in Sierra Nevada mixed conifer forests. However, selection for any one particular cover type was not sufficiently strong for us to infer selection of individual landownership types, in spite of differences in forest conditions among ownerships. Collectively, our findings suggest that privately-owned lands used in our study may harbor more suitable spotted owl foraging habitat than previously recognized. Finally, given the importance of understanding the relationship between landowner management priorities and the resultant pattern of vegetation on lands with different ownerships, the development of forest management strategies relevant for broad-scale conservation of the Sierra Nevada forest will benefit from effective collaboration between forest managers, landowners, and research organizations.

Wildlife use and select habitat at multiple scales, sometimes leading to conflicting interpretations of the importance of various habitat features analyzed at different scales. Species can also exhibit affinities that are unique to portions within their larger distribution. Conservationists need spatially explicit information on habitat use to develop effective management strategies for priority species. This information can be difficult to obtain for species that are highly mobile or occupy large home ranges. In this study, we used a distance sampling approach to estimate multi-scale resource selection for a highly mobile raptor, Mississippi Kite (Ictinia mississippiensis), based on data collected from line transect surveys combined with plotting tools in a geographic information system. We compared land cover of kite detection points to randomly located points at fine and broad spatial scales in a portion of the species’ breeding range in the southern Great Plains, USA. Dominant cover in these landscapes is a mix of grasses, forbs, and expansive stands of a dwarf oak tree (Quercus havardii) generally

Selecting nesting habitat that minimizes predation risk but maximizes foraging success is one of the most important decisions in avian life history. This takes on added complexity when a predator is faced with the challenge of avoiding fellow predators. We assessed the importance of local and landscape vegetation, food abundance, and predation risk on nest site selection and nest survival in a subordinate raptor (Mississippi Kite; Ictinia mississippiensis) nesting in proximity to two superpredators, Red-tailed hawk (Buteo jamaicensis) and Great horned owl (Bubo virginianus). All three species nested in trees in a grassland landscape. In this landscape, kites favored upland trees and shrubs, avoiding their more typical riparian forest association elsewhere in the species' range. Compared to random conditions, kites selected nest sites with high tree density and more closed canopy in the surrounding area. Mississippi Kite selection was not related to food abundance but could be explained by the presence of superpredators (i.e., hawks and owls) selecting riparian woodland for their nests. Nest survival declined with proximity to superpredator nesting sites. Overall, our study demonstrates how landscape structure and superior predators shapes predation risk for subordinate predators. Our results emphasize the importance of spatial heterogeneity in presenting opportunities for subordinate predators to coexist in a landscape with important superpredators.

Extraction of oil and natural gas is an emerging source of anthropogenic disturbance that threatens wild populations and important wildlife habitats. We compared daily nest survival estimates of killdeer Charadrius vociferous at graveled oil pads to those that nested on native grass cover in western Oklahoma, USA in 2015 and 2017. We conducted weekly searches for nesting killdeer around oil pads and in pastures (grass cover) at the Packsaddle Wildlife Management Area April–June. Killdeer showed a strong selection for graveled oil pad over grass fields with 64% of all nest attempts occurring on oil pads. A higher proportion (64%) of the nests we found were in the gravel substrates of oil pads, and daily nest survival estimates for oil pad nests were lower than our estimates for nests in grass substrates. We also identified a difference in edge effects between the two nesting substrates with the probability of nest survival on oil pads highest closer to the edge of the patches and the probability of nest survival in grass cover highest in the interior of the patches. This is an indication that risk of nest failure on oil pads increased towards areas of high human use: Nest failure on oil pads was almost entirely due to destruction by moving vehicles and by oil workers performing routine operations at well sites. Our results demonstrate that modified landscapes attract native species but could function as ecological traps. Management efforts to reduce the effect of oil and natural gas development or similar forms of human land use modifications on co-occurring nesting birds will benefit from reduction in habitat conversion and incorporation of natural gas developments into conservation planning.

Sympatric predators are predicted to partition resources, especially under conditions of food limitation. Spatial heterogeneity that influences prey availability might play an important role in the scales at which potential competitors select habitat. We assessed potential mechanisms for coexistence by examining the role of heterogeneity in resource partitioning between sympatric raptors overwintering in the southern Great Plains. We conducted surveys for wintering Red‐tailed hawk (Buteo jamaicensis) and Northern Harrier (Circus cyanea) at two state wildlife management areas in Oklahoma, USA. We used information from repeated distance sampling to project use locations in a GIS. We applied resource selection functions to model habitat selection at three scales and analyzed for niche partitioning using the outlying mean index. Habitat selection of the two predators was mediated by spatial heterogeneity. The two predators demonstrated significant fine‐scale discrimination in habitat selection in homogeneous landscapes, but were more sympatric in heterogeneous landscapes. Red‐tailed hawk used a variety of cover types in heterogeneous landscapes but specialized on riparian forest in homogeneous landscapes. Northern Harrier specialized on upland grasslands in homogeneous landscapes but selected more cover types in heterogeneous landscapes. Our study supports the growing body of evidence that landscapes can affect animal behaviors. In the system we studied, larger patches of primary land cover types were associated with greater allopatry in habitat selection between two potentially competing predators. Heterogeneity within the scale of raptor home ranges was associated with greater sympatry in use and less specialization in land cover types selected.

The likelihood of encountering a predator influences prey behavior and spatial distribution such that non‐consumptive effects can outweigh the influence of direct predation. Prey species are thought to filter information on perceived predator encounter rates in physical landscapes into a landscape of fear defined by spatially explicit heterogeneity in predation risk. The presence of multiple predators using different hunting strategies further complicates navigation through a landscape of fear and potentially exposes prey to greater risk of predation. The juxtaposition of land cover types likely influences overlap in occurrence of different predators, suggesting that attributes of a landscape of fear result from complexity in the physical landscape. Woody encroachment in grasslands furnishes an example of increasing complexity with the potential to influence predator distributions. We examined the role of vegetation structure on the distribution of two avian predators, Red‐tailed Hawk (Buteo jamaicensis) and Northern Harrier (Circus cyaneus), and the vulnerability of a frequent prey species of those predators, Northern Bobwhite (Colinus virginianus). We mapped occurrences of the raptors and kill locations of Northern Bobwhite to examine spatial vulnerability patterns in relation to landscape complexity. We use an offset model to examine spatially explicit habitat use patterns of these predators in the Southern Great Plains of the United States, and monitored vulnerability patterns of their prey species based on kill locations collected during radio telemetry monitoring. Both predator density and predation‐specific mortality of Northern Bobwhite increased with vegetation complexity generated by fine‐scale interspersion of grassland and woodland. Predation pressure was lower in more homogeneous landscapes where overlap of the two predators was less frequent. Predator overlap created areas of high risk for Northern Bobwhite amounting to 32% of the land area where landscape complexity was high and 7% where complexity was lower. Our study emphasizes the need to evaluate the role of landscape structure on predation dynamics and reveals another threat from woody encroachment in grasslands.

The Grey-necked Picathartes Picathartes oreas is a globally threatened bird species in Africa with a wild population of less than 10,000 individuals. The Nigerian population, which has been poorly studied, is restricted to the forest of Cross River. This study re-assessed the distribution, breeding population, habitat use and current threats of the Grey-necked Picathartes by revisiting the 91 breeding sites identified during the first and only survey of the species in 1987. We estimated a breeding population of 164 individuals across 82 breeding sites. Only 72 breeding sites were found in the localities where 91 had been registered in 1987. Thirteen (18%) of these 72 sites were no longer active and showed evidence of human disturbance. The occurrence of Grey-necked Picathartes’ nest sites was positively predicted by higher number of emergent trees, larger rocks and negatively related to disturbance matrices. Similarly, larger colony sizes were associated with high canopy cover and rock height. Also, the p...

Wildland fire is a disturbance that shapes frequent-fire forest ecosystems and the life-histories of wildlife species that inhabit them. The California spotted owl (Strix occidentalis occidentalis) is an iconic old-forest species that evolved under a frequent-fire regime in western North America. While recent studies have focused on owl response to large, severe fire events, relatively little is known about how owls might respond to prescribed fires and wildfires managed for resource benefit. Therefore, understanding how owls use landscapes that are managed using fire may offer insight into how owls respond to fire management. We studied the breeding season nocturnal foraging habitat selection of 22 GPS-tagged California spotted owls in three national parks (Yosemite, Sequoia, and Kings Canyon) in the Sierra Nevada, California, USA where natural fires have largely been allowed to burn during the past 50 years and controlled burning has been used to target additional areas. Consistent with other studies of this species, owls selected forests dominated by medium and large trees and avoided areas with smaller trees within their home ranges based on step selection analysis. Owls neither selected nor avoided forests burned by low- and moderate-severity, or high-severity fires, yet avoided larger patches of severely-burned forest (odds of selection decreased by 20% for every 10 ha increase in severely-burned patch area). These results indicated the importance of patch characteristics, suggesting that larger patches reflected either lower quality foraging habitat or increased predation risk, even in these frequent-fire landscapes where “large” severely-burned patches were small compared to those common after megafires. Additionally, selection strength increased for areas burned recently by lower-severity fire and, to a lesser extent, by older fires (largely of lower severity) as the extent of these burned areas increased within individual home ranges. These results suggested that lower-severity fire benefitted spotted owls and that these benefits declined over time. Thus, our findings are consistent with the hypothesis that California spotted owls are adapted to historical frequent-fire regimes of overall lower-severity with small high-severity patches. We hypothesize that fire management, coupled with medium- and large-tree retention, likely maintains high quality spotted owl habitat and may contribute to the observed owl population stability in Sequoia and Kings Canyon National Parks, compared to declining populations on three national forests. Finally, our results indicated that fire management, as practiced in these national parks, could benefit owl conservation elsewhere if challenges to the reintroduction of frequent-fire regimes can be overcome.

Several species of wildlife are hunted around the world for the perceived potency of certain parts of their bodies in traditional medicine and in fetish practices. In Africa, many cultures require animal parts for a wide range of traditional and religious practices. This has resulted in the persecution of more than 354 bird species across the continent. In this study, we evaluated the drivers and frequency of human-related avian mortality focusing on the trade in avian body parts around major protected areas in the Cross River region of southeastern Nigeria. We conducted personal interviews with men from 18 villages in proximity to four natural areas in the region, and asked the men questions related to their knowledge of trade in avian body parts. From the responses obtained, we identified 27 bird species from 13 families in regional trade. Three of the top 5 most reported species are globally threatened. Both knowledge of and participation in the trade were pervasive across the study sites and across different occupational groups. 94% of respondents claimed knowledge of trade in avian body parts; 66% had participated in that trade in the last 2 years. To identify predictors of participation in the avian body part trade, we fitted all possible model combinations using the Generalized Linear Mixed Model approach and ranked them based on their AICc values. The top-ranked model identified age, average monthly income, perceived personal need for avian body parts, and number of wives as the top socio-economic drivers of participation. Younger people and villagers with low monthly income were more likely to participate in the trade. Probability of involvement also increased with the number of wives and a perceived personal need for avian body parts. The former may be an indication of a larger household that requires more resources to sustain it; the latter likely reflects personal conviction of the efficacy of using avian body parts in traditional medicine and other cultural practices. Our study highlights the importance of targeting socio-economic factors and integrating cultural needs of the people into conservation planning aimed at reducing human–wildlife conflicts.

The dependence of forest communities on bushmeat as a source of protein and income is a challenge to wildlife conservation in Sub-Saharan Africa. We investigated the use of caves and overhanging rocks as hunting camps and the consequences for breeding grey-necked picathartes Picathartes oreas in the forests of Cross River in south-east Nigeria. We recorded 84 nesting colonies during guided and random searches. We found 14 (16.7%) breeding sites that had been used as hunting camps, with evidence including fire stands, sleeping spots, cooking utensils and drying racks. Fire stands were the most frequently recorded evidence of camping and were found in 11 of the camps. At the 14 breeding sites only two nesting attempts were made by P. oreas during the survey. Thirty-seven nests (c. 95%) recorded in hunting camps were empty and showed no evidence of ongoing or potential breeding activities, suggesting that the nests may have been abandoned. We attributed the low nesting attempt rate to disturbance caused by hunters, who also affected breeding success through direct removal of eggs and fledglings from nests. We encourage conservation education for the protection of P. oreas and other threatened species in the region and recommend strict enforcement of wildlife laws and disciplinary sanctions. Given the role of the forests of Cross River as a critical habitat for several endemic and threatened species, management efforts targeted at improving the integrity of the forest will benefit grey-necked picathartes and other avian species of conservation concern.

Most of our understanding of territorial behaviour in birds comes from studies of temperate species. Territoriality and factors influencing territory size of tropical birds are still poorly studied. In this study, 11 territories of the Cinnamon-breasted Rock Bunting Emberiza tahapisi were measured in the Amurum Forest Reserve and adjoining farmlands. Factors influencing the habitat choice of this species were also studied. Territory sizes ranged from 0.1–0.3 ha with a mean territory size of 0.19 ± 0.1ha. Territory size decreased with increasing food abundance and increased with tree height and number of saplings. The birds did not show signs of territoriality in farmlands but flocked in small groups (mean group size 6.88 ± 0.89). Flock size also increased with increasing number of seeds. In the forested land, birds showed a preference for rocky outcrops, whereas in farmlands, they appeared to prefer open and newly cultivated farmlands with little or no ground cover. Understanding the influence of habitat ...

Landscape function is largely determined by landscape structure. Evidence suggests that landscape heterogeneity often benefits generalists over sympatric specialists. The scale at which animals perceive that heterogeneity likely varies across species and could play an important role in determining the species assemblages supported by different landscapes. In this study, we investigated the relative importance of landscape heterogeneity in the structuring of raptor assemblages in mixed-grass prairie. We compared niche breadth and overlap of 14 species in two landscapes that differed in heterogeneity. We used a modified line transect approach and distance sampling to determine approximate locations of raptors and mapped these locations in a GIS. We then compared land cover in buffered areas around detection locations to randomly selected locations at different scales. We calculated Outlying Mean Index to quantify niche breadth and compare among species. Species composition was similar in both landscapes, but niche characteristics differed according to heterogeneity. Raptor assemblages were better predicted by land cover composition in heterogeneous landscapes than by land cover configuration in homogenous landscapes. Outlying Mean Index analysis suggested that six of the 14 species occupied marginal niches and narrower niche breadths in homogeneous landscapes. None of these species demonstrated marginality but occupied broader niche breadths in heterogeneous landscapes. Our study provides evidence that heterogeneity is important in providing conditions necessary to support multiple, sympatric birds of prey in mixed-grass prairie. Species overlapped broadly under heterogeneity but less in landscapes with larger patches of distinct land cover types.