Nonrandom dispersal drives phenotypic divergence within a bird population

Gene flow through dispersal has traditionally been thought to function as a force opposing evolutionary differentiation. However, directional gene flow may actually reinforce divergence of populations in close proximity. This study documents the phenotypic differentiation over more than two decades in body size (tarsus length) at a very short spatial scale (1.1 km) within a population of pied flycatchers Ficedula hypoleuca inhabiting deciduous and coniferous habitats. Unlike females, males breeding in the deciduous forest were consistently larger than those from the managed coniferous forest. This assortment by size is likely explained by preset habitat preferences leading to dominance of the largest males and exclusion of the smallest ones toward the nonpreferred coniferous forest coupled with directional dispersal. Movements of males between forests were nonrandom with respect to body size and flow rate, which might function to maintain the phenotypic variation in this heritable trait at such a small spatial scale. However, a deeply rooted preference for the deciduous habitat might not be in line with its quality due to the increased levels of breeding density of hole‐nesting competitors therein. These results illustrate how eco‐evolutionary scenarios can develop under directional gene flow over surprisingly small spatial scales. Our findings come on top of recent studies concerning new ways in which dispersal and gene flow can influence microevolution.     

Nest Predation of Greater Sage-Grouse in Relation to Microhabitat Factors and Predators

ABSTRACT Nest predation is a natural component of greater sage-grouse (Centrocercus urophasianus) reproduction, but changes in nesting habitat and predator communities may adversely affect grouse populations. We used a 2-part approach to investigate sage-grouse nest predation. First, we used information criteria to compare nest survival models that included indices of common raven (Corvus corax) abundance with other survival models that consisted of day of incubation, grouse age, and nest microhabitat covariates using measurements from 77 of 87 sage-grouse nests. Second, we used video monitoring at a subsample of 55 of 87 nests to identify predators of depredated nests (n = 16) and evaluated the influence of microhabitat factors on the probability of predation by each predator species. The most parsimonious model for nest survival consisted of an interaction between day of incubation and abundance of common ravens (w_{ravenXincubation day} = 0.67). An estimated increase in one raven per 10-km transect survey was associated with a 7.4% increase in the odds of nest failure. Nest survival was relatively lower in early stages of incubation, and this effect was strengthened with increased raven numbers. Using video monitoring, we found the probability of raven predation increased with reduced shrub canopy cover. Also, we found differences in shrub canopy cover and understory visual obstruction between nests depredated by ravens and nests depredated by American badgers (Taxidea taxus). Increased raven numbers have negative effects on sage-grouse nest survival, especially in areas with relatively low shrub canopy cover. We encourage wildlife managers to reduce interactions between ravens and nesting sage-grouse by managing raven populations and restoring and maintaining shrub canopy cover in sage-grouse nesting areas.     

Corvids congregate to breeding colonies of a burrow‐nesting seabird

Egg predation is a major cause of reproductive failure among birds, and can compromise the viability of affected populations. Some egg predators aggregate near colonially breeding birds to exploit the seasonal increase of prey resources. We investigated spatial and temporal variations in the abundance of an egg predator (little raven Corvus mellori; Corvidae) to identify whether ravens aggregate spatially or temporally to coincide with any of three potential prey species: burrow‐nesting little penguin (Eudyptula minor; Spheniscidae), short‐tailed shearwater (Ardenna tenuirostris; Procellariidae), and surface‐nesting silver gull (Chroicocephalus novaehollandiae; Laridae). We derived spatially explicit density estimates of little ravens using distance sampling along line transects throughout a calendar year, which encompassed little penguin, short‐tailed shearwater and silver gull breeding and non‐breeding seasons. High raven abundance coincided temporally with penguin and gull egg laying periods but not with that of shearwaters. The spatial distribution of raven density corresponded with the little penguin colony but not with shearwater or gull colonies. Thus, the presence of little penguin eggs in burrows correlated strongly with little raven activity, and this implies that little ravens may have learnt to exploit the plentiful subsurface food resource of little penguin eggs. Corvid management may be required to maintain the viability of this socially and economically important penguin colony.     

Nest site selection of a primary hole‐nesting passerine reveals means to developing sustainable forestry

Anthropogenic habitat loss and fragmentation affect populations worldwide. For example, many bird populations of boreal forests have declined due to intensive forestry. To target conservation actions for such species, determining the key factors that affect their habitat selection is essential. Remote sensing methods provide highly potential means to measure habitat variables over large areas. We aim at identifying the key‐features of habitats by utilizing remote sensing data. As a case example, we study the nest site selection of a primary hole‐nesting passerine, the willow tit Poecile montanus, in a managed forest landscape. Using presence–absence data, we determine the most important habitat characteristics of the nest sites for three spatial scales by generalized linear mixed effect models. Our results highlight the importance of the availability of nesting sites – standing decaying deciduous trees – in the nest site selection of P. montanus. It seems to prefer moist habitats with high densities of deciduous trees and to avoid open areas, but does not require mature or intact habitats. Most of the nest site selection seems to occur within small scales. In this case, remote sensing data alone was insufficient for producing reliable models, but adding information of an ecologically important feature from direct field surveys greatly improved model performances. For the conservation and maintenance of dead wood dependent species, changes in forestry practices are necessary to keep the key characteristics of the habitat. Most importantly, continuous availability of standing decaying wood should be secured.     

Nesting preferences of common buzzard Buteo buteo and goshawk Accipiter gentilis in forest stands of different structure (Niepolomice Forest, Southern Poland)

Studies on nesting preferences of common buzzard and goshawk were carried out in two distinctly different parts of the Niepolomice Forest (S Poland): deciduous (oak-hornbeam wood) and coniferous. Characteristics of nest sites were determined on three spatial scales, separately for: (1) nest tree; (2) nest tree area (0.07 ha circle centred at nest tree) and (3) nest stand (15 ha circle centred at nest tree). Nesting preferences discovered for the nest tree and its surroundings, included height and diameter of trees, age of the forest stand, distance to the nearest open area or forest road and occurrence of open areas in the vicinity of the nest. In the diverse habitat of oak-hornbeam wood, more similar to natural woods, nest site selection operated on several levels, possibly starting at the most extensive end of the scale before narrowing to the selection of a particular nest tree. In the more homogeneous habitat of commercially exploited coniferous forest, the surrounding of the nest were found to be insignificant, and the nesting decisions were likely to be based principally on individual characteristics of a tree i.e. its shape and size, being suitable for nesting.     

Availability and selection of arboreal termitaria as nest-sites by Orange-fronted Parakeets Aratinga canicularis in conserved and modified landscapes in Mexico

Few studies have investigated the use of termitaria by nesting parrots, or how this may be affected by habitat transformation. We determined selection of termitaria by nesting Orange-fronted Parakeets Aratinga canicularis , and evaluated the effect of habitat transformation on the availability of termitaria nest-sites for Parakeets in the tropical dry forest of Western Mexico. Availability of termitaria was quantified in 24 survey plots in a factorial design of six 1-ha plots in each of conserved and modified, deciduous and semi-deciduous forest. Characteristics of termitaria were determined in survey plots, as well as 21 nest-termitaria used by Parakeets, and their nearest adjacent termitarium. There was an overall density of 1.6 termitaria/ha suitable for nesting by Parakeets, which did not differ between habitats, although only 8% of apparently suitable termitaria were occupied by nesting Parakeets. However, termitaria in conserved semi-deciduous forest were significantly higher above the ground, and termitaria in conserved deciduous forest were significantly smaller in volume. In the modified landscape, termitaria were significantly lower and their volume significantly larger than in conserved landscapes. Termitaria used by nesting parrots were at a significantly greater height above the ground than the nearest adjacent termitaria. Termitarium volume did not reliably predict the likelihood of nest-site selection, although Parakeets only used termitaria between 15 and 150 l. Parakeets nesting in modified habitats used termitaria at a significantly lower height than Parakeets nesting in conserved habitat. It is unclear whether this represents a decline in nest-site quality in modified habitats, which could affect reproductive success of Parakeet populations in fragmented landscapes.     

Comparison of novel and conventional methods of trapping ixodid ticks in the southeastern U.S.A.

Tick‐borne disease surveillance and research rely on resource‐effective methods for tick collection. This study compared the respective performances of several trapping methods in a mixed grassland–forest habitat in western Tennessee. To test for temporal differences in effectiveness, sites were sampled monthly (April–August 2013) using dry ice, dragging, flagging, sweep netting, carbon dioxide (CO₂) dragging and CO₂ flagging methods. To evaluate the effect of habitat on method effectiveness, four methods (dragging, CO₂ dragging, CO₂ flagging and dry ice) were compared in four habitat types (bottomland deciduous, upland deciduous, coniferous and grassland) in June 2014. In the temporal comparison, ticks were found to be most abundant in April and May, and there was a significant sampling period and method interaction, such that method effectiveness varied across sampling period. Sweep netting was significantly less effective than the other methods. In the habitat comparison, dry ice trap collections represented the most effective method in upland deciduous and coniferous habitats. Flagging using CO₂ was significantly less effective than CO₂ dragging and dragging in bottomland deciduous habitats. The success of the various collection methods did not differ significantly within grassland habitats. Overall, dry ice trapping and dragging were the most effective methods for tick collection across time and habitat.     

The effects of spatial and temporal ecological variation on fatty acid compositions of wild great tits Parus major

In birds, fatty acids (FA) have three main functions; they are structural components of cell membranes, metabolic fuel, and inflammatory molecules. Environmental factors, such as diet and ambient temperature, affect FA composition, thereby function and ultimately fitness. Thus, variation in FA compositions can be the underlying mechanism for varying performance of birds in different habitats. Here we examine variation in plasma FA composition in nestling and adult great tits Parus major, between 1) deciduous and coniferous, and 2) sun‐exposed and shaded habitats. The main results revealed that nestlings had a higher proportion of α‐linolenic acid (α‐LNA) in deciduous habitats and arachidonic acid in coniferous habitats. This reflects a difference in caterpillar availability between habitats with the deciduous habitat being caterpillar‐rich, whereas the coniferous habitats are rich in spiders. In addition, α‐LNA increased with nestling body condition in the coniferous habitat, supporting the importance of caterpillars for fledging success in this species. In line with dietary intake, the proportion of the essential α‐LNA and linoleic acid (LA) increased over the course of the day for all birds. In the deciduous habitat, adult females showed a positive association between LA and body condition. Furthermore, habitat sun‐exposure showed significant interactions with body condition for polyunsaturated FAs in nestlings, and with saturated FA in adult males, which is in accordance with the homeoviscous hypothesis stating that the proportion of saturated FA should decrease with decreasing ambient temperature. Taken together, small‐scale heterogeneity in habitat structure significantly influences FA compositions of great tits. Many of the results can be linked to dietary, and possibly, ambient temperature differences between habitats. These habitat effects on FA compositions can lead to different capacities of individual birds to deal with infections and low temperatures, two stressors that cause major mortality among wild birds.     

Fragments are not islands: patch vs landscape perspectives on songbird presence and abundance in a harvested boreal forest

The boreal mixed-wood forest of northern Alberta. Canada is characterized by a mosaic of deciduous and coniferous forest patches. Recently, the deciduous portion of the forest was allocated for industrial logging. Widespread habitat loss and fragmentation may negatively affect birds and other wildlife. Most research on the effects of habitat loss on bird abundance has focussed on the forest as a patch or island in a matrix of non-habitat, but some species of songbird may use both the forest patch and the matrix. We hypothesized that some species of songbird might be able to compensate for a loss of deciduous forest by moving into other habitat types (termed "habitat compensation"). We report on a replicated field investigation in which we assessed the response of songbirds to commercial timber harvest by first examining their abundance within deciduous forest only, and then adding the clearcuts and coniferous forest in the surrounding areas to the analysis for a broader, landscape view of the system. Bird communities in deciduous and coniferous habitats had significant overlap in species composition: there was less overlap between forest and clearcuts. The shift from patch-centred to landscape sampling altered our interpretation of over half of the most common species' responses to logging in at least one year, suggesting that habitat compensation may have been occurring. However, significant variation in responses of species was observed between the two study areas. Our past reliance on island biogeographic and other single habitat approaches may be inappropriate for this system, and we stress that a broad, landscape view is required to properly assess and interpret species' responses to habitat loss and fragmentation.     

Nesting Habitat of the Lilac-crowned Parrot in a Modified Landscape in Mexico

Parrot populations are being increasingly pressured to occupy modified or fragmented landscapes, yet little is known of the habitat requirements of most species, particularly with regard to the effects on breeding habitat. We evaluated nesting habitat of the lilac-crowned parrot Amazona finschi in the modified landscape of coastal Michoacan in Mexico. We located 90 parrot nests in 12 tree species in Michoacan, with lilac-crowned parrots presenting a narrow niche-breadth of tree species used for nesting. Considering an additional 82 nest trees recorded for lilac-crowned parrots in Jalisco, we determined a 51 percent similarity in cavity resource use by parrots in the two dry forest regions. Overall, the predominant nest tree species with 76 percent of nests were Astronium graveolens , Piranhea mexicana , Brosimum alicastrum , and Tabebuia spp., all characteristic of semi-deciduous forest. Only 8 percent of nests occurred in trees characteristic of deciduous forest. Parrots utilized large trees with canopy level cavities as nest sites, and preferred conserved semi-deciduous forest for nesting, with fewer nests than expected in deciduous forest and transformed agricultural land. Nest areas in semi-deciduous forest occurred on significantly steeper terrain, as remnant semi-deciduous forest is restricted to steep ridges and canyons. Those parrot nests in modified habitats and forest patches were located near to continuous forest, with nest trees in open agricultural land being significantly closer to continuous forest than nests in disturbed forest patches. These results demonstrate the importance of conserved semi-deciduous forest as breeding habitat for the threatened, endemic lilac-crowned parrot, making wild populations of the species vulnerable to the high rate of transformation and fragmentation of tropical dry forest.     

Habitat partitioning in endangered Cantabrian capercaillie Tetrao urogallus cantabricus

The endangered Cantabrian capercaillie (Tetrao urogallus cantabricus) lives at the southern edge of tetraonids’ distribution range, in entirely deciduous forests. Its conservation planning has been always lek-centred. There is very little information about the specific habitat requirements of hens and broods, even though reproductive success appears to be a limiting factor. We analysed summer surveys from 1997 to 2004, carried out to estimate the reproductive success of the population. We compared the habitat characteristics at different spatial scales of hens with broods, broodless hens, and cocks in summer, with the better known spring habitat in display areas. Summer habitat showed higher proportion of open areas and was associated with more rugged zones at moderate spatial scales (78 ha) than spring habitat at display areas. Cocks and hens showed summer habitat partitioning; hens were associated with higher proportions of open and shrubby habitats. Furthermore, broodless hens preferred areas with higher slope variability than the display and summer areas preferred by cocks. These differences may reflect the sexual dimorphism of the species in reproductive role, energetic demands and conspicuousness. At larger spatial scales a previously developed habitat suitability model performed well to predict good brood-rearing areas. Hens with broods were located in the best-preserved areas in the range, mainly characterized by higher proportion of forest cover at a large (50 km²) scale. We suggest that these characteristics indicate refuge habitats where Cantabrian capercaillie can still breed successfully.     

Reproductive success of Tree Pipits Anthus trivialis in relation to habitat selection in conifer plantations

Aspects of the reproductive success of Tree Pipits Anthus trivialis were examined in relation to broad‐scale habitat and nest‐site selection in Thetford Forest, a coniferous plantation forest in eastern England. Three habitat classes were defined corresponding to previously reported densities of Tree Pipits: clearfell and recently planted stands (habitat class A: low density), stands 2–5 years old (B: high density) and stands 6 years or older (C: low density). The preference for 2–5‐year‐old stands indicated by higher densities was supported by the timing of territory settlement. Tree Pipits also showed distinct preferences for nest‐site characteristics that were relatively consistent across habitat classes and throughout the breeding season. At the ‘habitat scale’, results were consistent with the predictions of the ideal despotic distribution model. First clutches were laid significantly earlier in the preferred habitat class B. Overall nesting success (i.e. the proportion of nests producing fledglings), but not clutch size, also varied between habitats, being greater in habitat classes B and C than in habitat class A. The variation in overall nesting success between habitats was primarily driven by low nest survival rates during the laying/incubation period in clearfell and recently planted stands. Nest survival rates during the nestling period were lower in the preferred 2–5‐year‐old (and older) stands and declined over the course of the study. Preferences for nest‐site characteristics (at least for those that were measured) provided no apparent benefit to nest survival rates. Overall nesting success thus appeared to be determined at the habitat scale, perhaps because the broad differences in cover between habitats affected the likelihood of nest predation (the main cause of nest failure). It is suggested that the very low nesting success experienced by Tree Pipits in clearfell and new stands may be one factor in the species’ relative avoidance of this habitat and preference for 2–5‐year‐old stands.     

Application of ecological-niche factor analysis in habitat assessment of giant pandas

Ecological-niche factor analysis (ENFA) is a multivariate approach to study geographic distribution of species on a large scale with only “presence” data. It has been widely applied in many fields including wildlife management, habitat assessment and habitat prediction. In this paper, this approach was applied in habitat suitability assessment for giant pandas in Pingwu County, Sichuan Province, China. With “presence” data of giant pandas and remote sensing data, habitat suitability of pandas in this county was evaluated based on ENFA model, and spatial distribution pattern of nature reserves and conservation gaps were then evaluated. The results show that giant pandas in this county prefer high-elevation zones (> 2128 m) dominated by coniferous forest, and mixed coniferous and deciduous broadleaf forest, and avoid deciduous broadleaf forest and shrubs. Pandas avoid staying at habitats with human disturbances. Farmland is a major factor threatening panda habitat. Panda habitat is mainly distributed in north and west of Pingwu with a total area of 234033 hm², 106345hm² for suitable habitat and 127688 hm² for marginally suitable habitat). 3 nature reserves were located in Pingwu, covering over 49.2% of total suitable habitat and 45.6% of total marginally suitable habitat. Although 47.2% of panda habitat was in reserves under protection, connectivity between reserves was weak and a conservation gap existed in the north part of Pingwu. Thus, a new nature reserve in Baima and Mupi should be established to link the isolated habitats.     

The relevance of non-farmland habitats, uncropped areas and habitat diversity to the conservation of farmland birds

Use of non-farmland habitats by species generally perceived as 'farmland birds' is common, yet these habitats are not always considered in conservation strategies aimed at population recovery. At the national scale, many farmland species occur in landscapes not dominated by farmland. An analysis of distribution atlas data coupled with remotely sensed habitat data showed that for 16 out of 28 farmland species, less than half of the breeding range was associated with high cover of lowland farmland. However, with a few exceptions, populations breeding in non-farmland habitats are likely to depend on farmland at some time in the year. Within farmland landscapes, uncropped areas and patches of non-farmland habitat can provide nesting, foraging or roosting resources. Habitats that are scarce on farmland and that provide potential supplementary or complementary resources to those available within the productive areas of farmland include ruderal vegetation, rough grassland and scrub. Enhancing habitat diversity through provision of modest quantities of these habitats will benefit farmland birds. Complete knowledge of year-round habitat requirements and patterns of resource use at all scales is needed if robust national conservation plans are to be developed for farmland species. Similarly, interactions between the farmland and non-farmland sections of populations need to be determined.     

Occupancy Models of Nesting-Season Habitat Associations of Red-Shouldered Hawks in Central Minnesota

ABSTRACT Red-shouldered hawks (Buteo lineatus) are a species of special conservation concern in much of the Great Lakes region, and apparent population declines are thought to be primarily due to habitat loss and alteration. To evaluate red-shouldered hawk-habitat associations during the nesting season and at the landscape scale, we conducted repeated call-broadcast surveys in central Minnesota, USA, across 3 landscapes that represented a range of landscape conditions as a result of differing management practices. In 2004, we conducted repeated call-broadcast surveys at 131 locations in 2 study areas, and in 2005, we surveyed 238 locations in 3 study areas. We developed models relating habitat characteristics at 2 spatial scales to red-shouldered hawk occupancy and assessed support for these models in an information-theoretic framework. Overall, a small proportion of nonforest (grass, clear-cut area, forest <5 yr old), and a large proportion of mature deciduous forest (>40 yr old), had the strongest association with red-shouldered hawk occupancy (proportion of sites occupied) at both spatial scales. The landscape conditions we examined appeared to contain a habitat transition important to red-shouldered hawks. We found, in predominately forest landscapes, the amount of open habitat was most strongly associated with red-shouldered hawk occupancy, but in landscapes that included slightly less mature forest and more extensive open habitats, the extent of mature deciduous forest was most strongly associated with red-shouldered hawk occupancy. Our results suggested that relatively small (<5 ha) patches of open habitat (clear-cuts) in otherwise forested landscapes did not appear to influence red-shouldered hawk occupancy. Whereas, in an otherwise similar landscape, with smaller amounts of mature deciduous forest and larger (>15 ha) patches of open habitat, red-shouldered hawk occupancy decreased, suggesting a threshold in landscape composition, based on both the amount of mature forest and open area, is important in managing forest landscapes for red-shouldered hawks. Our results show that during the nesting season, red-shouldered hawks in central Minnesota occupy at similar rates landscapes with different habitat compositions resulting from different management strategies and that management strategies that create small openings may not negatively affect red-shouldered hawk occupancy.     

Seasonal use by birds of stream-side riparian habitat in coniferous forest of northcentral British Columbia

To determine use of riparian habitats by birds in the northern coniferous forest of British Columbia, we censused birds and vegetation along 500 m transects placed parallel and perpendicular to three second-order streams. Censuses were conducted during spring, summer, autumn, and winter to investigate how use of riparian habitat changed seasonally. Stream-side riparian zones were characterized by a dense understorey of deciduous vegetation not found in the upslope forest. Nine bird species preferred the riparian understorey for breeding, six preferred it only during migration. Neotropical migrants (16 of 46 species) were more closely associated with stream-sides than year-round residents (11 species). Some breeding birds (five species) were significantly negatively associated with riparian habitats. The density of riparian birds declined with distance upstream but did not decline up to 250 m away from the stream. The more extensive riparian areas downstream supported a greater density of birds in all seasons compared to upstream areas, but more species only in spring and autumn. Species that nested in non-riparian areas in summer used riparian habitat in autumn, making riparian corridors in the northern coniferous forest important during migration. Maintaining both riparian and upslope habitats is necessary to preserve species diversity al the landscape level.     

Geographic variation in habitat structure for the wood warblers in Maine and Minnesota

The habitats occupied by species of wood warblers (Emberizidae) were compared at two study areas, Itasca State Park, Minnesota and Mount Blue State Park, Maine. Univariate comparisons of each variable of habitat structure show geographic differences for each species of warbler. Habitats available were also different because small trees were always more dense in Maine than in Minnesota. The Black-throated Green Warbler had the most dissimilar habitat with 9 of 11 variables different at the two sites.Cluster analysis identified four generalized habitat groups containing (1) species occupying territories with high percent shrub cover, (2) forest species from Maine, (3) forest species from Minnesota and (4) open country species. Reciprocal averaging ordination was used to identify habitat gradients at each site. The first axis of the Maine and Minnesota ordinations was a gradient from open country with dense ground cover to forest vegetation. The second axes differed, however. In Minnesota, the gradient separated medium deciduous trees from large conifers, whereas in Maine, vegetation graded from medium and large deciduous trees to coniferous habitats. Spearman rank correlation indicated that the warblers were similarly arranged along both habitat axes at each site despite differences in axis loadings of habitat variables.A combined reciprocal averaging ordination separated forest and shrub-forest edge species in Maine from the same two species groups in Minnesota along a smaller to larger tree axis. The results clearly demonstrate that habitat structure is not consistent throughout the range of many widely distributed species. It is suggested that the similar arrangement of species along the habitat axes probably results from an individualistic distribution of opportunistic bird species. Variation is probably induced at a site level by intraspecific competition for territories, small-scale vegetation dynamics, and resource fluctuation that occurs both within and between seasons.     

Integrating population size analysis into habitat suitability assessment: implications for giant panda conservation in the Minshan Mountains,China

Compared to conventional approaches, the integration of population size analysis with habitat suitability assessment on a large scale can provide more evidence to explain the mechanisms of habitat isolation and fragmentation, and thus make regional conservation plans. In this paper, we analyzed the habitat suitability for giant pandas in the Minshan Mountains, China, using the ecological-niche factor analysis (ENFA) method, and then evaluated the current conservation status of this endangered species. The results showed that (1) giant pandas were distributed in a narrow altitudinal range in which vegetation cover was dominated by coniferous forest, mixed coniferous and deciduous broadleaf forest, and deciduous broadleaf forest with scattered bamboo understory, and (2) roads and human settlements had strong negative effects on the panda habitat selection. According to habitat analysis, the total habitat area of giant panda in the Minshan Mountains was 953,173 ha, which was fragmented into 12 habitat units by major roads, rivers, and human settlements. The habitat of the mid-Minshan was less fragmentized, but was seriously fragmented in the north. The panda population size estimation showed that 676 individuals inhabited the study area, and 94.53% of them were in the mid-Minshan, but small panda populations less than 30 individuals inhabited the isolated and fragmented habitat patches in the north. The nature reserves in the Minshan Mountains have formed three conservation groups, which covered 41.26% of panda habitat and protected 70.71% of panda population of the study area, but there still exists two conservation gaps, and the connectivity among these reserves is still weak. Due to habitat isolation and extensive human disturbances, giant pandas in the north (i.e., Diebu, Zhouqu, and Wudou) are facing threats of local extinction. In order to protect pandas and their habitats in this area, some effective conservation approaches, such as establishing new reserves in gap areas, creating corridors among patches, and seasonally controlling traffic flux in key roads, should be implemented in the future to link these isolated habitats together.     

Variation in behavioral traits of two frugivorous mammals may lead to differential responses to human disturbance

Human activities can lead to a shift in wildlife species’ spatial distribution. Understanding the specific effects of human activities on ranging behavior can improve conservation management of wildlife populations in human‐dominated landscapes. This study evaluated the effects of forest use by humans on the spatial distribution of mammal species with different behavioral adaptations, using sympatric western lowland gorilla and central chimpanzee as focal species. We collected data on great ape nest locations, ecological and physical variables (habitat distribution, permanent rivers, and topographic data), and anthropogenic variables (distance to trails, villages, and a permanent research site). Here, we show that anthropogenic variables are important predictors of the distribution of wild animals. In the resource model, the distribution of gorilla nests was predicted by nesting habitat distribution, while chimpanzee nests were predicted first by elevation followed by nesting habitat distribution. In the anthropogenic model, the major predictors of gorilla nesting changed to human features, while the major predictors of chimpanzee nesting remained elevation and the availability of their preferred nesting habitats. Animal behavioral traits (body size, terrestrial/arboreal, level of specialization/generalization, and competitive inferiority/superiority) may influence the response of mammals to human activities. Our results suggest that chimpanzees may survive in human‐encroached areas whenever the availability of their nesting habitat and preferred fruits can support their population, while a certain level of human activities may threaten gorillas. Consequently, the survival of gorillas in human‐dominated landscapes is more at risk than that of chimpanzees. Replicating our research in other sites should permit a systematic evaluation of the influence of human activity on the distribution of mammal populations. As wild animals are increasingly exposed to human disturbance, understanding the resulting consequences of shifting species distributions due to human disturbance on animal population abundance and their long‐term survival will be of growing conservation importance.     

Can pinewoods provide habitat for a deciduous forest specialist? A two-scale approach to the habitat selection of Bechstein's bat

Populations of Myotis bechsteinii in Sierra de Cazorla, Segura y Las Villas Natural Park (southwestern Spain) survive in a large, old-growth coniferous woodland, which is in contrast with known ecological preferences of the species. We tracked ten lactating females and studied patterns of habitat selection by Bechstein's bat (Myotis bechsteinii) at two spatial scales: macrohabitat and microhabitat, regarding forest essence (coniferous vs. deciduous). The tracked individuals always foraged within forested areas and did not use areas devoid of trees. At the macrohabitat level, no positive selection of deciduous stands was apparent, suggesting selection studies of coarse resolution may not be able to capture subtle selection patterns. At the microhabitat level Myotis bechsteinii selected deciduous patches within the coniferous matrix, therefore, our results corroborate the perception of this species as dependent of services provided by deciduous woodlands. Larger foraging home ranges and commuting distances as compared with other Mediterranean localities suggest that our studied population inhabits a marginal or suboptimal environment in terms of habitat quality. We argue that this population of Bechstein's bat has survived as a relict one probably as a consequence of fragmentation and transformation of deciduous forest ecosystems in the Mediterranean range.