Habitat Associations Research Articles

Habitat associations and threat vulnerabilities of seahorses and pipefishes (Syngnathidae) in Biscayne National Park, Florida, USA

Habitat loss is a primary threat to seahorses, pipefishes, and their relatives (family Syngnathidae) globally. Conservation intervention is difficult or ineffective when species lack critical habitat information. To better understand the habitat associations of syngnathids we conducted underwater visual surveys of 79 sites in three habitat categories (Reef, Continuous, and Discontinuous Submerged Rooted Vegetation) in Biscayne National Park (BNP), a coastal Marine Protected Area (MPA) in southeastern Florida. We recorded nine syngnathid species in our surveys; presence/ absence data was analyzed alongside a suite of abiotic and biotic variables. Nonparametric statistical tests indicated that syngnathids were significantly more abundant inside Biscayne Bay and we did not detect any syngnathids at reef sites—located outside Biscayne Bay—despite reef-associated species being previously reported in BNP. Additional analyses indicated that sites where syngnathids were present were characterized by fine sediment, reduced horizontal visibility, high seagrass coverage, and low coverage of sessile benthic invertebrates and reef-associated turf algae. The most important predictor of syngnathid presence was a predominance of fine sediment—an indicator of low-velocity hydrodynamic conditions—and seagrass coverage at occupied sites was nearly double that of unoccupied sites. Variation in habitat use among the three most abundant sympatric syngnathids (Hippocampus zosterae, S yngnathus scovelli, and Syngnathus floridae) indicates niche partitioning based on salinity, local hydrodynamic regime, and seagrass coverage. Our study points to the value of protecting sheltered seagrass beds; heightened vulnerability to habitat change—driven by watershed development, impacts from fisheries, recreation and tourism, and climate change—necessitates coordinated management of land use outside of the protected area.

The critical role of coastal protected areas in buffering impacts of extreme climatic conditions on bird diversity and their ecosystem services' provisioning in the Eastern Cape Province, South Africa.

In this study, we documented the diversity of bird species in the Eastern Cape coastal nature reserves (i.e., Hluleka, Dwesa, Silaka and Mkhambati nature reserves), and determined the potential role of each bird species in habitat maintenance using two functional traits (i.e., body mass and feeding mode) as the function's proxy. We applied the timed species count approach during bird observations, coupled with drive-by surveys to maximise spatial coverage of each nature reserve over four years. To evaluate functional diversity, bird species were classified based on functional traits such as the adult body, and their potential ecological role derived from their feeding mode and habitat associations. Over 864 h, we accumulated 818 bird records containing 178 different bird species that were classified into 58 families with 32 species occurring in all nature reserves. Shannon-Wiener Diversity Indices showed very high overall species diversity across the nature reserves (H > 3.5) with no differences detected across sites. Although no significant correlations between vegetation changes measured through Normalised Difference vegetation Index (NDVI) in each nature reserve and the number of bird records, forest bird species were dominant (42.1%; N = 178) throughout years of observation and diversity remained high (H > 3.5). Bird species abundance only increased significantly across all nature reserves during 2018-2019. All four nature reserves had a similar distribution of bird functional traits with both high functional richness (FRic = 1), and divergence (FDiv = 0.8) and moderate evenness (FEve = 0.4). Multiple Correspondence Analysis (MCA) demonstrated a positive correlation between bird sizes and functions with large birds mainly associated with predators and carrion. Small birds and medium birds had a similar composition of species in terms of functionality being seed dispersers across the nature reserves. A significant effect that insectivores and carrions displayed in MCA plots, suggest the availability of indirect pollination services. Despite extreme drought conditions across the country in 2019, NDVI levels remained largely consistent over time in these four reserves; and thus, they offer important refuge for birds during extreme climatic conditions such as drought.

Interactions among rainfall, fire, forbs and non-native grasses predict occupancy dynamics for the endangered Pacific pocket mouse (Perognathus longimembris pacificus) in a Mediterranean-type ecosystem

It is important to understand species-habitat relationships to implement effective adaptive management for rare species. However, it can be challenging to assess habitat associations and their relationships to abiotic stressors in dynamic habitats without the insights that can be gained from long-term monitoring. We report results from the first six years of extensive track tube monitoring of the largest two of three remaining extant populations of federally endangered Pacific pocket mouse (Perognathus longimembris pacificus) in a coastal Mediterranean-type ecosystem on Marine Corps Base, Camp Pendleton in southern California, USA. We used dynamic occupancy and structural equation modeling to assess potential drivers of population trends that included habitat, fire history, rainfall, disturbance, and the presence of other small mammals. We found that the variables that best predicted mouse occupancy were moderate to high forb and perennial herb cover (40–80%), and moderate to high open ground (20–70%) and low non-native grass cover (<20%), Non-native grass cover (>20%) was also a strong predictor of lower PPM colonization and increased extinction probabilities, with the extent of non-native grass cover being strongly influenced by annual rainfall and recency of fire. Our study adds to the growing literature on effects of invasive annual grasses on native species in Mediterranean-type ecosystems. We suggest that habitat management could be based upon promotion of open forb and perennial herb dominated habitats with reduction of non-native grasses by prescribed fire and other methods. These types of spatial and temporal monitoring programs can support land managers by creating a monitoring and management feedback loop. They can reveal landscape and environmental variables associated with species persistence, inform habitat management goals, and help managers to assess the success of management actions on populations of conservation concern.

Macrofungi as Medicinal Resources in Uzbekistan: Biodiversity, Ethnomycology, and Ethnomedicinal Practices.

Interest in edible and medicinal macrofungi is millennial in terms of their uses in health and food products in Central Asia, while interest in inedible and medicinal macrofungi has grown in popularity in recent years. Edible and inedible medicinal basidiomycetes were collected during field surveys from different regions of Uzbekistan. The morphological characters and similarity assessment of rDNA-Internal Transcribed Spacer sequence data were used to measure diversity and habitat associations. A number of 17 species of medicinal macrofungi of ethnomycological and medicinal interest was found associated with 23 species of trees and shrubs belonging to 11 families and 14 genera. Polyporaceae and Hymenochaetaceae were represented by the highest number of species followed by Ganodermataceae, Fomitopsidaceae, Auriculariaceae, Cerrenaceae, Grifolaceae, Phanerochaetaceae, Laetiporaceae, Schizophyllaceae, and Stereaceae. The highest number of medicinal basidiomycete species was reported in the following host genera: Acer, Betula, Celtis, Crataegus, Juglans, Juniperus, Lonicera, Malus, Morus, Platanus, Populus, Prunus, Quercus, and Salix. An updated list of edible and inedible medicinal mushrooms identified in Uzbekistan, their morphological characteristics, and phylogenetic placement are given for the first time. Information is provided on their uses in traditional and modern medicine. Their bioactive compounds and extracts can be applied as medicines, as well as food and cosmetic ingredients.

Phenotypic plasticity and genetic diversity shed light on endemism of rare Boechera perstellata and its potential vulnerability to climate warming.

The rapid pace of contemporary environmental change puts many species at risk, especially rare species constrained by limited capacity to adapt or migrate due to low genetic diversity and/or fitness. But the ability to acclimate can provide another way to persist through change. We compared the capacity of rare Boechera perstellata (Braun's rockcress) and widespread B. laevigata to acclimate to change. We investigated the phenotypic plasticity of growth, biomass allocation, and leaf morphology of individuals of B. perstellata and B. laevigata propagated from seed collected from several populations throughout their ranges in a growth chamber experiment to assess their capacity to acclimate. Concurrently, we assessed the genetic diversity of sampled populations using 17 microsatellite loci to assess evolutionary potential. Plasticity was limited in both rare B. perstellata and widespread B. laevigata, but differences in the plasticity of root traits between species suggest that B. perstellata may have less capacity to acclimate to change. In contrast to its widespread congener, B. perstellata exhibited no plasticity in response to temperature and weaker plastic responses to water availability. As expected, B. perstellata also had lower levels of observed heterozygosity than B. laevigata at the species level, but population-level trends in diversity measures were inconsistent due to high heterogeneity among B. laevigata populations. Overall, the ability of phenotypic plasticity to broadly explain the rarity of B. perstellata versus commonness of B. laevigata is limited. However, some contextual aspects of our plasticity findings compared with its relatively low genetic variability may shed light on the narrow range and habitat associations of B. perstellata and suggest its vulnerability to climate warming due to acclimatory and evolutionary constraints.

Biology of Yucatán Box Turtles (Terrapene yucatana) in Northern Yucatán.

Yucatán Box Turtles (Terrapene yucatana) are the only fully tropical lineage of box turtles (Terrapene spp.). We studied the ecology, movements, behavior, and habitat associations of T. yucatana in northern Yucatán, México, over 218 field days from 2014-2019. We estimated the size of two subpopulations to comprise 36.6 and 3.0 turtles, with corresponding densities of 2.29 and 0.39 turtles/ha, respectively. We obtained 2,808 radio locations from radiotelemetry of 20 adults. We estimated an annual survivorship rate over a 5-yr period exceeding 0.989. For both sexes combined, the average annual 95% minimum convex polygon (MCP) home range size was 0.684 ha, and the average distance between consecutive annual home range centroids was 22.5 m. In 2 of 5 yr, males exhibited significantly larger 95% MCP home ranges than females. We observed feeding, courtship, and fighting in the wild between June and December. Females moved more than males in July, when gravid turtles were also observed. We found that T. yucatana was positively associated with Mimosa sp. and Bromelia spp. The use of aquatic habitats was infrequent (0.17%). Our findings support the conclusion that T. yucatana, an allopatric and fully tropical lineage, is an interior forest and thornscrub species that occurs at low densities. In such undisturbed contexts, T. yucatana may exhibit high survivorship rates, small home range size, and home range fidelity that underscore the importance of large-scale forest conservation efforts in concert with the targeted protection of documented Yucatán Box Turtle populations.

Abundance and population growth estimates for bare-nosed wombats.

Wildlife managers often rely on population estimates, but estimates can be challenging to obtain for geographically widespread species. Spotlight surveys provide abundance data for many species and, when conducted over wide spatial scales, have potential to provide population estimates of geographically widespread species. The bare-nosed wombat (Vombatus ursinus) has a broad geographical range and is subject to spotlight surveys. We used 19 years (2002-2020) of annual spotlight surveys to provide the first estimates of population abundance for two of the three extant bare-nosed wombat subspecies: V. u. ursinus on Flinders Island; and V. u. tasmaniensis on the Tasmanian mainland. Using distance sampling methods, we estimated annual rates of change and 2020 population sizes for both subspecies. Tasmanian mainland surveys included habitat data, which allowed us to also look for evidence of habitat associations for V. u. tasmaniensis. The average wombat density estimate was higher on Flinders Island (0.42 ha-1, 95% CI = 0.25-0.79) than on the Tasmanian mainland (0.11 ha-1, CI = 0.07-0.19) and both wombat subspecies increased over the 19-year survey period with an estimated annual growth rate of 2.90% (CI = -1.7 to 7.3) on Flinders Island and 1.20% (CI = -1.1 to 2.9) on mainland Tasmania. Habitat associations for V. u. tasmaniensis were weak, possibly owing to survey design; however, we detected regional variation in density for this subspecies. We estimated the population size of V. u. ursinus to be 71,826 (CI = 43,913-136,761) on Flinders Island, which when combined with a previously published estimate of 2599 (CI = 2254-2858) from Maria Island, where the subspecies was introduced, provides a total population estimate. We also estimated 840,665 (CI = 531,104-1,201,547) V. u. tasmaniensis on mainland Tasmania. These estimates may be conservative, owing to individual heterogeneity in when wombats emerge from burrows. Although these two subspecies are not currently threatened, our population estimates provide an important reference when assessing their population status in the future, and demonstrate how spotlight surveys can be valuable to inform management of geographically widespread species.

Observations of the association by early-juvenile western rock lobsterPanulirus cygnuswith seagrass assemblages (Decapoda: Achelata: Palinuridae)

AbstractThe fishery of the western rock lobster, Panulirus cygnusGeorge, 1962, is Australia’s most valuable wild-caught single-species fishery. Recruitment in some regions of the fishery was observed to be significantly lower than expected after the 2010/2011 West Australian marine heatwave that caused extensive disturbance of dominant coastal habitats. This event generated interest in the study of the factors influencing survival and recruitment of post-larval benthic P. cygnus after settlement. The habitat associations of the highly cryptic post-settlement early-juveniles were previously unknown, with only anecdotal observations of individuals within limestone crevices in nearshore habitats. Our study used early-juveniles derived from ongoing monitoring of puerulus settlement to examine their habitat association mechanism in mesocosm experiments. Comparison of common nearshore habitat assemblages (bare sand, limestone crevices, and seagrasses (Posidonia and Amphibolis) at varying seagrass densities) found that most early-juveniles associated strongly with Amphibolis assemblages at high stem densities (~2,100 stems m–2). A shift in association between Amphibolis fronds and stems at high stem density to Amphibolis-shaded sand and leaf debris at low stem density indicated active habitat selection by early-juveniles. Habitat choices were tested with the scents of prey items and habitat types within Amphibolis assemblages using Y-maze bioassays. No significant olfactory choices were found, suggesting that habitat associations may be driven by multiple cues. Our study provides new laboratory-based insights into the habitat association of early-juvenile P. cygnus and suggests changes in seagrass assemblage identity and density are likely to be important. Further experimentation is needed to define the cues driving these patterns. The impact of habitat change on recruitment in this important fishery remains unknown and should be an objective of future research.

Habitat associations of woody plant species in evergreen–deciduous broadleaf karst forests in southwest China

The effects of habitat filtering on community assembly have been extensively researched, and topography has been identified as a critical factor influencing the spatial distribution of trees. In this study, a 25-ha plot was established in karst evergreen–deciduous broadleaf forests in southwestern China. Eight topographical factors were used to divide plots into four habitat types, i.e., hilltop, steep slope, gentle slope, and depression, using a multivariate regression tree. A total of 85 evergreen and deciduous tree species were recorded in these four habitats and classified into three life stages, the differentiation of which was assessed using torus-translation tests. A total of 65 species significantly positively associated with at least one habitat and 79 species significantly negatively associated with at least one habitat were identified. Most species, whether evergreen or deciduous, exhibited a positive correlation with steep slopes, whereas relatively few species were adapted to depressions. Moreover, the percentage of evergreen species positively associated with hilltops and steep slopes was higher than that of deciduous species. Both evergreen and deciduous species showed an increasing percentage of positive correlation with hilltops from the sapling stage to the mature stage. However, more evergreen species grew on steep slopes in the sapling stage, whereas deciduous species grew in the mature stage. Canonical correspondence was used to analyze the relationship between species and the eight topographical factors. Regardless of life form or life stage, results showed that species distribution was significantly affected by topography. Furthermore, the distribution of evergreen species on sapling-stage trees was found to be more influenced by topography, whereas deciduous species were more influenced by topography in the mature stage. Finally, elevation was identified as the most crucial topographical factor affecting species distribution.

Contribution to the Cimicidae (Hemiptera: Heteroptera) fauna from Argentina: biology and geographical distribution.

The bed bug family Cimicidae (Hemiptera: Heteroptera) constitutes a group of specialized haematophagous ectoparasitic insects with about 110 species worldwide and 13 species in the Neotropics. Here we provide biological and faunistic observations for 4 out of the 8 species recorded in Argentina. Propicimex tucmatiani (Wygodzinsky, 1951) was recorded for the first time in the Province of Santa Fe and we provide the first barcode sequence for this species. Acanthocrios furnarii (Cordero & Vogelsang, 1928), a mainly ornithophilic species, has been found in a human apartment in Buenos Aires and was probably attacking humans. Bertilia valdiviana (Philippi, 1865) had been reported in 1950 in the Province of Ro Negro, we discuss its potential habitat and host association after visiting the only location where this species had been recorded so far in Argentina. Moreover, we provide some natural history data, i.e. developmental stages, sex ratio and feeding habit of the parrot parasite Cyanolicimex patagonicus Carpintero, Di Iorio, Masello & Turienzo, 2010 from a colony in El Condor (Province of Ro Negro).

Habitat selection of southern giant petrels: potential environmental monitors of the Antarctic Peninsula

AbstractThe southern giant petrel (Macronectes giganteus) is a widely distributed top predator of the Southern Ocean. To define the fine-scale foraging areas and habitat use of Antarctic breeding populations, 47 southern giant petrels from Nelson Island were GPS-tracked during the summers of 2019–2020 and 2021–2022. Step-selection analysis was applied to test the effects of environmental variables on habitat selection. Visual overlap with seal haul-out sites and fishing areas was also analysed. Birds primarily used waters to the south of the colony in the Weddell and Bellingshausen seas. Females showed a broader distribution, reaching up to -70°S to the west of Nelson Island, while males were mainly concentrated in waters off the northern Antarctic Peninsula. Habitat selection of both sexes was associated with water depth and proximity to penguin colonies. Both overlapped their foraging areas with fishing sites and females in particular overlapped with toothfish fishery blocks in Antarctica and with fishing areas in the Patagonian Shelf. Due to their habitat associations and overlap with fisheries, when harnessed with tracking devices and animal-borne cameras, giant petrels can act as platforms for monitoring the condition and occurrence of penguin colonies, haul-out sites and unregulated fisheries on various temporal and spatial scales in Antarctica.

Automated wildlife image classification: An active learning tool for ecological applications

Wildlife camera trap images are being used extensively to investigate animal abundance, habitat associations, and behavior, which is complicated by the fact that experts must first classify the images to retrieve relevant information. Artificial intelligence systems can take over this task but usually need a large number of already-labeled training images to achieve sufficient performance. This requirement necessitates human expert labor and poses a particular challenge for projects with few cameras or short durations. We propose a label-efficient learning strategy that enables researchers with small or medium-sized image databases to leverage the potential of modern machine learning, thus freeing crucial resources for subsequent analyses.Our methodological proposal is twofold: On the one hand, we improve current strategies of combining object detection and image classification by tuning the hyperparameters of both models. On the other hand, we provide an active learning system that allows training deep learning models very efficiently in terms of required manually labeled training images. We supply a software package that enables researchers to use these methods without specific programming skills and thereby ensure the broad applicability of the proposed framework in ecological practice.We show that our tuning strategy improves predictive performance, emphasizing that tuning can and must be done separately for a new data set. We demonstrate how the active learning pipeline reduces the amount of pre-labeled data needed to achieve specific predictive performance and that it is especially valuable for improving out-of-sample predictive performance.We conclude that the combination of tuning and active learning increases the predictive performance of automated image classifiers substantially. Furthermore, we argue that our work can broadly impact the community through the ready-to-use software package provided. Finally, the publication of our models tailored to European wildlife data enriches existing model bases mostly trained on data from Africa and North America.

Tropical insectivorous birds’ predation patterns that promote forest–farmland trophic connectivity for integrated top–down pest biocontrol

Although conversion of natural forest to agriculture can negatively impact biodiversity in many ways, some affected species may respond by dispersing across the forest–farmland eco-zone, thereby facilitating functional connections through food-web interactions beneficial to crop production and forestry. This study examined patterns of Lepidoptera (butterflies and moths), Hemiptera (bugs), and Coleoptera (beetles) herbivory, and insectivorous bird predation within forest-adjacent farms in western Kenya, and how these processes trophically connect the two ecosystems to promote pest biocontrol. Through δ13C and δ15N stable isotope analyses, proportions of maize, farmland legumes and forest trees in pest diets, and pest-prey in bird’s diets were estimated. Birds’ habitat associations and diet specializations’ influence on pest consumption and basal plant carbon levels in birds’ tissues were determined to evaluate birds’ pest-biocontrol potential. Maize was the mostly consumed plant especially by Lepidoptera, but forest trees were peimarily consumed by Coleoptera and Hemiptera. In turn, Lepidoptera were mainly consumed by forest-associated birds, whereas Hemiptera and Coleoptera were mostly consumed by farmland-associated birds. Thus, birds showed cross-habitat pest consumption tendencies, though diet-specialization was unimportant in predicting those tendencies. Muscicapidae (flycatchers and allies); Hirundinidae (swifts and swallows); Motacillidae (pipits and wagtails); and Ploceidae (weavers) birds showed the highest contributory potential for pest biocontrol of Lepidoptera pests, but Estrildidae (manikins and waxbills), Muscicapidae, and Malaconotidae (boubous and gonoleks) birds showed the best potential against Hemiptera and Coleoptera. Furthermore, more maize basal carbon was assimilated by forest-associated compared to farmland-associated birds, whereas most basal carbon from farmland legumes and forest trees were assimilated by farmland birds, suggesting that unlike pest-prey choice, basal plant carbon pathways to avian insectivorous consumers did not strongly mirror birds’ habitat associations. Lepidoptera and Hemiptera were potentially the most significant interhabitat trophic connector arthropods, and for birds, Muscicapidae, Ploceidae, and Estrildidae. These findings show that such functional connectivity may be enhanced through increasing structural cover elements that promote insectivorous birds’ dispersal between farmland and adjacent forests to boost their pest-regulation ecosystem service contribution. The results serve to inform effective management practices by agronomists, foresters, and land-use planners toward promoting landscape-scale-integrated pest management for sustainable agriculture and biodiversity conservation.

Wildlife habitat association over a twelve-year period (2008–2020) in the Greater Mahale Ecosystem, western Tanzania

The Greater Mahale Ecosystem (GME) in western Tanzania hosts high faunal biodiversity, including charismatic species such as elephants and chimpanzees. Across the GME, habitat occurs in differently administered, unprotected and protected areas, including village land, forest reserves, and national parks. Areas of lower protective status are prone to deforestation and land cover changes. These land cover changes influence suitable habitat itself as well as the connectivity between habitat patches, but the impact on different mammal species in this region is unknown. In this study, we investigated changes in habitat availability by creating species distribution models for 11 medium-large mammal species based on species occurrence data collected from 2008 to 2020. We tested habitat associations for each species and evaluated the importance of the static predictor variables elevation, slope, aspect and terrain-ruggedness and the dynamic predictor variables distance to deforestation, percent forest, vegetation intensity, and vegetation variability, retrieved through remotely sensed data analysis. Our models suggest habitat declined for most, but not all species. Whilst elephants and buffalo lost more than 50 % of available habitat during this period, primates exhibited habitat stability. Habitat losses were pronounced in the southeast of the GME. Slope, elevation and median tasseled-cap wetness index (vegetation intensity) and distance to deforestation were the most important predictor variables. Our study presents a spatially and temporally explicit estimation of habitat changes in a critically important, biodiverse region undergoing drastic land cover changes. We call for consideration in land-use planning to foster connectivity and landscape integrity to protect and conserve wildlife across the ecosystem.

Southern Red-backed Vole (Myodes gapperi) habitat associations in northern New England forests

Abstract Understanding habitat selection is fundamental to addressing the response of a species to disturbance. Because resources are unevenly distributed across the landscape, habitat selection occurs at multiple scales. We used capture–mark–recapture and radiotelemetry techniques to quantify the macrohabitat and microhabitat associations that define space use of the Southern Red-backed Vole (Myodes gapperi) in northeastern forests. Macrohabitat characteristics were evaluated at the scale of the forest stand by comparing conditions between visited and unvisited trap stations and suggest red-backed voles have an affinity for locations with higher basal area of Eastern Hemlock (Tsuga canadensis) and more coarse woody material. For microhabitat characteristics we modeled the influence of forest structure, ground cover, and geographic features on home range, specifically core area placement. We found that Southern Red-backed Vole core areas were associated with higher Red Maple (Acer rubrum) basal area, deeper leaf litter, greater density of hemlock stems, and closer proximity to water. The affinity of southern red-backed voles for eastern hemlock raises questions about population persistence and shifts in distribution as eastern hemlock stands are replaced by hardwood stands following infestation by Hemlock Woolly Adelgid.

A case study on joint species distribution modelling with bird atlas data: Revealing limits to species' niches

Growing interest in biodiversity mapping has spurred the development of species distribution atlases, often mainly based on citizen-science projects. Atlas data have been frequently exploited to model species' ecological niches and distributions on a species-by-species basis. However, spatial autocorrelation and phylogenetic relatedness among species complicate the statistical description of species' niches. Also, the effects of species' traits and co-occurrences on species-habitat relationship are commonly disregarded. In this work, we build a hierarchical multi-species model based on a major citizen-science project (the third Spanish breeding bird atlas) that simultaneously accounts for spatial, phylogenetic and trait-based dependencies. We predict the distributions of species niches, species richness and community traits along regional ecological gradients. Climate, habitat associations and species' traits all contribute (in this order) to structuring species' distributions. Species richness increases towards intermediate climatic conditions and with aquatic habitat cover and decreases with increasing forest and woody agricultural land cover. Species were distributed along regional climate gradients in accordance with their global thermal niches. Forest habitats favoured assemblages dominated by generalist, small-sized and cold-dwelling species with limited migratory behaviour. Increasing sampling effort augmented the model performance. Model performance was weaker for rare species and those with decreasing population sizes, likely due to their low niche saturation. Overall, we show that ecological relationships generalize from local to large scales and may be eludicated from atlases based on citizen-science mapping efforts.

Diversity and habitat associations of non-volant small mammals in forest patches of Kathmandu Valley, Nepal

Diversity and habitat associations of non-volant small mammals in forest patches of Kathmandu Valley, Nepal

Binturong ecology and conservation in pristine, fragmented and degraded tropical forests

AbstractThe persistence of seed-dispersing animals in degraded habitats could be critical for ensuring the long-term conservation value and restoration of forests. This is particularly important in Southeast Asia, where &gt; 70% of the remaining forest areas are within 1 km of a forest edge, and many are degraded (e.g. logged). We synthesized information on the habitat associations of the binturong Arctictis binturong, a large, semi-arboreal, frugivorous civet and one of the most important seed dispersers in the region, especially for figs (Ficus spp). We adopted a multiscale approach by employing ensemble species distribution modelling from presence-only records, assessing landscape-scale variation in detection rates in published camera-trap studies and using hierarchical occupancy modelling to assess local (i.e. within-landscape) patterns observed from 20 new camera-trap surveys. Contrary to prior reports that binturongs are strongly associated with intact forests, the species was equally present in degraded forests and near forest edges where sufficient forest cover was maintained (&gt; 40% forest cover within a 20-km radius). The species also tolerates moderate incursions of oil palm plantations (&lt; 20% of the area within a 20-km radius covered by oil palm plantations). The relative resilience of binturongs to habitat degradation could be in part because of behavioural adaptations towards increased nocturnal activity. These results support the notion that key seed dispersers can persist and maintain their ecological function in degraded forests.

Intraspecific variation in habitat relationships for pygmy rabbits: Implications for conservation of habitat specialists

AbstractEnvironmental relationships can differ across the geographic range of species, especially for widespread generalists. Because habitat specialists are more vulnerable to environmental changes, incorrect assumptions about consistent habitat associations could hinder strategic conservation efforts. We used species distribution models (SDMs) to evaluate intraspecific variation in habitat associations for a habitat specialist of conservation concern, the pygmy rabbit (Brachylagus idahoensis), which is endemic to the sagebrush biome of the western United States. Our goal was to model habitat associations for pygmy rabbits across a portion of their range to evaluate regional variation and contrast predictions with results from a model developed at the rangewide extent. We created inductive SDMs using maximum entropy methods within five ecological regions that encompassed about 20% of the species rangewide distribution and spanned diverse environmental gradients. We included a suite of environmental predictor variables representing topography, vegetation, climate, and soil characteristics. Results of the regional models identified substantial variation in habitat associations across the five regions, with each retaining a unique set of environmental predictors. Bioclimatic variables were the most influential environmental parameters in all five regions, but the specific variables differed. The models developed at regional extents predicted smaller areas of habitat (an average of 15% less for suitable habitat and 80% less for primary habitat) than predictions generated from a model developed at the rangewide extent. Because bioclimatic variables were effective in discriminating areas used by pygmy rabbits, they also provided an opportunity to assess potential changes in habitat distribution by incorporating future climate projections. Distributions modeled under two mid‐century emission scenarios projected substantial reductions in suitable habitat for pygmy rabbits across most regions and pronounced variation among regions in the magnitude and direction of the climate effects. Collectively, results of this work underscore the need to incorporate regional variation in habitat associations into planning for current and future conservation and management strategies.

Trait-independent habitat associations explain low co-occurrence in native and exotic birds on a tropical volcanic island.

On oceanic islands, strong human impacts on habitats, combined with introductions of exotic species, modify the composition of terrestrial bird assemblages and threaten their ecological functions. In La Réunion, an oceanic island located in the Madagascan region, a national park was established in 2007 to counter the ecosystem-level effects of three centuries of habitat conversion, native species destruction and exotic species introductions. Here, we investigated how bird assemblages were structured in these human-modified landscapes, 10 years before the national park set out its first conservation measures. We used a combination of multivariate statistics and generalized additive models to describe variations in the taxonomic and functional composition and diversity of 372 local bird assemblages, encompassing 20 species, along gradients of habitat composition and configuration. We found that native species were tied to native habitats while exotic species were associated with urban areas and man-modified landscape mosaics, with some overlap at mid-elevations. Species' trophic preferences were segregated along habitat gradients, but ecological traits had an overall weak role in explaining the composition of species assemblages. Hence, at the time of the survey, native and exotic species in La Réunion formed two spatially distinct species assemblages with contrasting ecological trait suites that benefited from antagonistic habitat compositions and dynamics. We conclude that our results support the analysis of historical data sets to establish reference points to monitor human impacts on insular ecosystems.