Influence Habitat Use Research Articles

Ecological dynamics and coexistence patterns of wild and domestic mammals in an abandoned landscape

The issue of agricultural land abandonment in southern Europe has raised concerns about its impact on biodiversity. While abandoned areas can lead to positive developments like creating new habitats and restoring native vegetation, they can also result in human–wildlife conflicts, particularly in areas with extensive farming and free‐ranging livestock. To understand habitat selection and use of livestock and wild ungulates, it is essential to study their spatial and temporal distribution patterns. In this context, we conducted a long‐term large mammal monitoring project using camera traps in the Peneda‐Gerês National Park in northern Portugal. Our primary focus was on exploring habitat preferences, occupancy dynamics, and potential spatial use correlations between domestic and wild species, utilizing dynamic occupancy models. Most wild species exhibited stable area use patterns, while domestic species experienced marginal declines, and the Iberian ibex displayed signs of repopulation. We observed distinct effects of habitat variables on occupancy, colonization, and extinction, revealing species‐specific patterns of habitat utilization. Human disturbance had a notable impact on domestic species but did not affect wild ones. Camera sensitivity emerged as a critical factor, enhancing detection probability for all species. Additionally, habitat and weather variables exerted varying effects on detection probabilities, underscoring the necessity of accounting for these factors in modeling the detection process. We found shared habitat preferences between cattle and horses, both positively correlated with wolves, suggesting potential human–wildlife conflicts. Despite extensive spatial overlap, domestic and wild species seem to exhibit ecological independence possibly due to distinct strategies and low predation pressure. Overall, the study emphasizes the multifaceted factors influencing habitat use. The observed species associations contribute to understanding ecological relationships and potential resource competition, emphasizing the importance of considering environmental variables for effective wildlife conservation and management.

Influence of microclimate and forest management on bat species faced with global change.

Climate refugia, areas where climate is expected to remain relatively stable, can offer a near-term safe haven for species sensitive to warming temperatures and drought. Understanding the influence of temperature, moisture, and disturbance on sensitive species is critical during this time of rapid climate change. Coastal habitats can serve as important refugia. Many of these areas consist of working forestlands, and there is a growing recognition that conservation efforts worldwide must consider the habitat value of working lands, in addition to protected areas, to effectively manage large landscapes that support biodiversity. The sensitivity of forest bats to climate and habitat disturbance makes them a useful indicator taxon. We tested how microclimate and forest management influence habitat use for 13 species of insectivorous bats in a large climate refugium in a global biodiversity hotspot. We examined whether bat activity during the summer dry season is greater in forests where coastal fog provides moisture and more stable temperatures across both protected mature stands and those regularly logged. Acoustic monitoring was conducted at a landscape scale with 20 study sites, and generalized linear mixed models were used to examine the influence of habitat variables. Six species were positively associated with warmer nighttime temperature, and 5 species had a negative relationship with humidity or a positive relationship with climatic moisture deficit. Our results suggest that these mammals may have greater climate adaptive capacity than expected, and, for now, that habitat use may be more related to optimal foraging conditions than to avoidance of warming temperatures and drought. We also determined that 12 of the 13 regionally present bat species were regularly detected in commercial timberland stands. Because forest bats are highly mobile, forage over long distances, and frequently change roosts, the stewardship of working forests must be addressed to protect these species.

Coexistence in multi-use landscape: linking human activities with functional traits of wild mammals in southern India

ContextHuman presence and land-use activities influence habitat use and activity of species. It is crucial to study the ecological and anthropogenic determinants that drive these relationships.ObjectivesWe investigated the effects of land-use change and human presence on the habitat use of seven mammalian species and on their activity patterns.MethodsWe conducted a camera-trapping survey in Ballari district, India. We deployed camera-traps at 1457 sampling grid cells across Protected Areas (PAs), Reserved Forests (RFs), and adjoining fringe mosaic farmlands (FMFLs). We assessed the influence of 19 covariates related to habitat features, landscape-level human presence, climate, and local-level human presence on species habitat use. We examined the diel activity patterns and activity levels of mammals within different land-use types.ResultsFour species exhibited a net negative response to increasing human presence, while three species exhibited positive responses. Respectively, proximity to farmlands, and settlements positively influenced habitat use by Panthera pardus, and Lepus nigricollis,. Increasing direct human presence negatively affected Sus scrofa habitat use. Large body-sized species exhibited higher diurnal activity in PA/RF compared to FMFL while smaller-sized (≤ 2.2 kg) species maintained similar activity patterns across land-use types. Generalist meso-predators exhibited more diurnal activity in RF/FMFL.ConclusionsEcological and life history traits were strong predictors of species responses to increasing human presence which favoured smaller and generalist species. These insights into the complex mechanisms through which human activities shape mammal communities are important landscape level perspectives on conservation.

Habitat Use and Diet Composition of the Common Eland (Tragelaphus oryx) in Ngorongoro Conservation Area, Tanzania

Ngorongoro Conservation Area (NCA) is renowned worldwide for its multiple land use where pastoralism and wildlife conservation co-exist. Thus, the NCA must meet a delicate balance of competing needs between livestock and wildlife. Currently the NCA is conducting resettlement program to facilitate pastoralists who are willing to move and resettle outside of the conservation area in order to reduce the number of people and livestocks in NCA. The common eland (Tragelaphus oryx) are among the large herbivore species found in the NCA that might be affected by possible competition between livestock and wildlife. The information on this species including habitat utilization and feeding ecology is limited. This study therefore, investigated the factors influencing habitat use and diet composition of the common eland (Tragelaphus oryx) in NCA. Data were collected along 82 pre-established transects using direct field survey. The study therefore assessed habitat use, distribution patterns, diet composition and conservation threats facing the common eland in NCA, The results indicated that the grassland habitat was mainly used by elands (> 85% in both dry and wet seasons), while other habitats were least used (< 15%). Eland diet composition varied significantly among plant species, with the animals most frequently feeding on Themeda triandra but rarely on Vachellia tortilis and Hibiscus aponeurus. The study concludes with recommendations for enhancement of grassland habitat management and reduced anthropogenic activities to enhance eland conservation in NCA.

Avian species functional diversity and habitat use: The role of forest structural attributes and tree diversity in the Midlands Mistbelt Forests of KwaZulu-Natal, South Africa.

Forest transformation has major impacts on biodiversity and ecosystem functioning. Identifying the influence of forest habitat structure and composition on avian functional communities is important for conserving and managing forest systems. This study investigated the effect of forest structure and composition characteristics on bird species community structure, habitat use and functional diversity in 14 Mistbelt Forest patches of the Midlands of KwaZulu-Natal in South Africa. We surveyed bird communities using point counts. We quantified bird functional diversity for each forest patch using three diversity indices: functional richness, functional evenness and functional divergence. We further assessed species-specific responses by focussing on three avian forest specialists, orange ground-thrush Geokichla gurneyi, forest canary Crithagra scotops and Cape parrot Poicephalus robustus. We found that bird community and forest-specialist species responses to forest structure and tree species diversity differed. Also, forest structural complexity, canopy cover and tree species richness were the main forest characteristics better at explaining microhabitat influence on bird functional diversity. Forest patches with relatively high structural complexity and tree species richness had higher functional richness. Different structural characteristics influenced habitat use by the three forest specialists. Tree species diversity influenced C. scotops and G. gurneyi positively, while P. robustus responded negatively to forest patches with high tree species richness. Our study showed that site-scale forest structure and composition characteristics are important for bird species richness and functional richness. Forest patches with high tree species diversity and structural complexity should be maintained to conserve forest specialists, bird species richness and functional richness.

Factors determining the seasonal habitat use of Asian elephants in the Western Ghats of India

AbstractAsian elephants (Elephas maximus) are globally endangered, and their populations persist in several meta‐populations within fragmented landscapes across their distribution. Developing landscape‐level management plans for elephants requires reliable information on the pattern and determinants of their distribution across relevant spatial and temporal scales. The Brahmagiri‐Nilgiri‐Eastern Ghats Landscape (Nilgiri landscape) of peninsular India supports the largest breeding population of Asian elephants globally. The Wayanad Plateau, a wet forest tract in the dry forest‐dominated Nilgiri landscape, witnessed extensive forest fragmentation recently and evolved as a forest‐agriculture matrix. We predicted that habitat use by elephants in the Wayanad Plateau would be high during summer because of the availability of numerous perennial streams and associated swamps that retain water and soil moisture for plant growth over the dry season. We also hypothesized that elephants would use areas with greater forest cover that are removed from human settlements. We used an occupancy‐based approach that accounts for detection probability to understand factors influencing habitat use by elephants in summer (low rainfall, high temperature) and post‐monsoon (largely rainless winter conditions but with abundant forage and water) in 2019 and 2020. As expected, the intensity of habitat use was higher during the summer than during the post‐monsoon season. Elephants used habitats near perennial water sources and with greater forest cover, avoiding areas with high human disturbances. We emphasize the importance of areas that provide key resources for elephants during resource scarcity and the need to prevent habitat degradation for long‐term persistence of elephants and mitigation of human–elephant conflict.

Larval cisco and lake whitefish exhibit high distributional overlap within nursery areas

AbstractCoregonine fishes, including lake whitefish (Coregonus clupeaformis) and cisco (C. artedi), are socioecologically important in the Laurentian Great Lakes and of conservation concern, but the processes driving recruitment variability are unclear. In Lake Ontario, cisco and lake whitefish exhibit similar spawning behaviours and early life histories, but population trajectories are diverging. One hypothesis is that sympatric cisco and lake whitefish larvae occupy distinct habitats and experience dissimilar local environmental conditions, despite co‐occurrence within nursery areas. We described the spatiotemporal distributions of larval cisco and lake whitefish among multiple Lake Ontario embayment nursery areas, characterised physical habitat features associated with their distributions, determined the degree of spatial habitat partitioning between species and evaluated how habitat niche divergence occurred along an ontogenetic progression. Both species were widely distributed across larval nursery areas, though lake whitefish were less abundant and more narrowly distributed than cisco. Within the yolk sac stage, lake whitefish occupied more nearshore, shallower and colder waters than cisco, indicating potential habitat niche partitioning between congeners. However, distributional differences were subtle and likely driven by differential hatch timing and staggered ontogenetic habitat shifts. Combined, our results illustrate similar habitat use between cisco and lake whitefish through the larval stage and demonstrate that ontogeny and species‐specific phenology influence habitat use for these species. This study provides additional evidence that the early life histories of cisco and lake whitefish are highly similar and does not support the hypothesis that larval habitat use differences are a major driver of differential recruitment success for these species.

Influences on koala habitat selection across four local government areas on the far north coast of NSW

AbstractConserving habitats crucial for threatened koala (Phascolarctos cinereus) populations requires rating habitat quality from a fine spatial scale to patches, landscapes and then regions. The koala has a specialized diet focused on the leaves of a suite of Eucalyptus species. We asked: what are the key regional influences on habitat selection by koalas in the far north coast of New South Wales? We addressed this question by investigating the multi‐scale factors, and within‐scale and cross‐scale interactions, that influence koala habitat selection and distribution across four local government areas on the far north coast of New South Wales. We assembled and analysed a large data set of tree selection, identified by the presence of scats, in a wide range of randomly selected 5 × 5 km grids across the region. This resulted in more than 9000 trees surveyed for evidence of koala use from 302 field sites, together with associated biophysical site features. The dominant factor influencing habitat use and koala occurrence was the distribution of five Eucalyptus species. Koalas were more likely to use medium‐sized trees of these species where they occurred on soils with high levels of Colwell phosphorous. We also identified new interactions among the distribution of preferred tree species and soil phosphorous, and their distribution with the amount of suitable habitat in the surrounding landscape. Our study confirmed that non‐preferred species of eucalypts and non‐eucalypts are extensively used by koalas and form important components of koala habitat. This finding lends support to restoring a mosaic of koala‐preferred tree species and other species recognized for their value as shelter. Our study has provided the ecological foundation for developing a novel regional‐scale approach to the conservation of koalas, with adaptability to other wildlife species.

Summer distribution and habitat preference of beluga whale social groups in the Eastern Beaufort Sea

In social animals, group composition can cause variations in individual needs that can influence responses to habitat trade-offs, such as predator exposure or foraging opportunities. The Eastern Beaufort Sea beluga whales ( Delphinapterus leucas (Pallas, 1776)) form different group types and cover multiple habitat types in summer. This study compares the habitat preference of three beluga social group types: (1) individual belugas, (2) groups of adults, and (3) groups with at least one calf. Observations were collected during aerial surveys in July and August 2019. For each month, beluga distribution was analyzed with hierarchical generalized additive models, as a function of group type and four covariates: sea surface temperature, bathymetry, slope, and distance to the coastline. Group type, water temperature, and bathymetric features best explained beluga distribution. In July, groups of adults preferred the continental shelf, whereas individual belugas and groups with calves preferred the continental slope. In August, groups of adults and groups with calves were found in Amundsen Gulf at similar depths. For both months, individual belugas associated more with deeper and colder areas. The preferences often corresponded to previously published distributions of the beluga's main prey species, suggesting that foraging opportunities and size-related energy requirements strongly influence habitat use.

Assessing individual movement, habitat use, and behavior of non-breeding marine birds in relation to prey availability in the US Atlantic

Resource availability is a key factor driving marine bird movements and distributions, but direct information on prey availability is difficult to obtain at relevant scales. We present novel methods for describing multi-scale trophic associations, combining movement analyses of marine birds with estimates of forage fish surface aggregations from digital aerial survey data and species occupancy from bottom trawl survey data. We analyzed satellite telemetry data from northern gannets Morus bassanus, red-throated loons Gavia stellata, and long-tailed ducks Clangula hyemalis in the US Atlantic during the non-breeding period. Using discrete-time hidden Markov models to distinguish area-restricted (i.e. putative foraging) from transit movements, we examined how environmental factors influence movement, and how forage fish species distributions and surface aggregations influence habitat use by gannets and loons that have greater dietary reliance. Our results suggest that chlorophyll a concentration significantly affected movement behavior across species, highlighting the importance of higher-productivity areas around estuaries during colder months when regional productivity is low. Though variable across species and seasons, spatial cross-correlation analysis revealed that herring species (Family Clupeidae), including Atlantic menhaden Brevoortia tyrannus, may be important resources; it also showed positive spatial correlations with forage fish aggregations. This suggests that prey patch dynamics and factors driving aggregation formation may be as important as species composition. However, spatial patterns were generally low (<0.3), suggesting a mismatch in spatiotemporal resolution, exemplifying the challenges in quantifying trophic relationships in marine systems. Disentangling predator-prey relationships is critical to understanding the mechanisms driving marine bird behavior in rapidly changing marine systems.

Large Felid and Peccary Habitat Use in Isolated and Contiguous Forest in Panamá: Implications for Conservation

Background and Research Aims Wildlife research in Panamá has focused primarily on protected areas along the Central Cordillera, where much of the remaining mature rainforest habitat is located. Information on large felid and prey habitat use in isolated habitats in Panamá is therefore limited. Here, we estimated occupancy and detection probabilities, as affected by habitat and anthropogenic influences, for 2 felid species (jaguars [ Panthera onca] and pumas [ Puma concolor]), and 2 prey species (white-lipped peccaries [ Tayassu pecari] and collared peccaries [ Pecari tajacu]). Methods Camera trap surveys were conducted during 2014–2015 at Cerro Hoya National Park (CHNP), an isolated remnant of tropical rainforest habitat, and Darién National Park (DNP), a large tract of continuous rainforest habitat. We used single-season, single-species occupancy modeling to estimate probabilities of detection and habitat use of our focal species. Results Three of the 4 focal species were detected at both sites, excluding white-lipped peccary at CHNP. Detection of jaguars and white-lipped peccaries at DNP was highest in February, while detection of collared peccaries at DNP and pumas at CHNP was highest in May and April, respectively. Peccary habitat use was uniform across sites and unaffected by habitat covariates. Both felids preferred habitat further away from anthropogenic disturbance, and jaguars preferred habitat at higher elevations than pumas. Conclusion We further confirm the presence of jaguars and likely local extirpation of white-lipped peccaries in CHNP. Temporal variations influenced detections of focal species. Habitat use of felids was negatively affected by anthropogenic disturbance and elevation. Implications for Conservation Habitat fragmentation and human activities negatively influenced habitat use of felids at both study areas. Given that CHNP serves as one of the last remnants of forest habitat outside the Central Cordillera, we recommend that CHNP be considered a top priority area for wildlife conservation in Panamá.

Implications of stock structure in understanding juvenile Atlantic cod (Gadus morhua) habitat suitability in the Gulf of Maine

The misalignment between the spatial structure of biological stocks and management units can be a potentially significant obstacle to the recovery of collapsed stocks. This study examines how ignoring biological stock structure in habitat modeling can prevent the detection of spatially explicit habitat relationships, using juvenile Atlantic cod (Gadus morhua) as an example. A recent reevaluation of cod stock structure found that there are likely two separate biological units in the eastern Gulf of Maine (EGOM) and western Gulf of Maine (WGOM) within the current Gulf of Maine (GOM) management unit. These two areas differ in their ranges of depth, bottom temperature, and sediment type, variables that influence habitat use by juvenile Atlantic cod (20–50 cm). When applying a Habitat Suitability Index (HSI) model within these distinct spatial areas, juvenile cod in the EGOM biological unit were found to occupy wider ranges of habitat, including deeper and colder waters, with larger seasonal differences in overall habitat quality than in the WGOM biological unit. When modeling HSIs over the entire GOM management unit and ignoring biological stock structure, results aligned closely with WGOM trends, but did not identify the same seasonal habitat suitability shifts, and the unique habitat associations in the EGOM were not identified. Juvenile survival may be more important than adult survival and fecundity in rebuilding cod stocks in the GOM, and can increase through the protection of quality habitat. Habitat conservation measures, such as area closures, may be implemented over suboptimal areas if spatially explicit habitat relationships are ignored, failing to slow population declines and further hindering recovery of collapsed stocks such as Atlantic cod.

Impact of rice paddy agriculture on habitat usage of migratory shorebirds at the rice paddy scale in Korea

Approximately 58 shorebird species, including endangered and threatened species, use various habitats while traveling on their long-distance migratory routes in the East Asian-Australasian Flyway (EAAF). Coastal rice paddies in midwestern Korea, which are located in the EAAF, serve as inland wetlands and provide important stopover sites for long-distance migratory shorebirds. We studied how shorebird population density is affected across periods, time since habitat formation, and field type, at the rice field scale. The shorebirds most frequently observed in rice paddies were, in order, black-tailed godwits (Limosa limosa), common greenshanks (Tringa nebularia), and wood sandpipers (T. glareola). Black-tailed godwits and wood sandpipers were affected by time since formation, field type, and water level, whereas field type affected common greenshanks. We propose that (1) flooding time, (2) shallow water level, (3) harrowed field type, and (4) 5–7 days of management intervals at paddy fields are important factors influencing shorebird species density, although all the factors did not influence common greenshank density. We propose that environmental characteristics derived from field management in rice paddies influence habitat use by migratory shorebirds. These factors need to be considered to systematically protect and manage shorebirds that use rice paddies as stopovers during their migration events.

Effects of Pine Forest Management Practices on Bat Functional Traits in a Subtropical Region

Changes in landscape environmental characteristics may influence habitat use by bat species as well as species composition and community functional structure. Landscape features may drive the functional role variability of bat species on the ecosystems. Consequently, landscapes may change the degree of functional differentiation between species. We have evaluated the effect of pine forest monoculture and their environmental characteristics on the distribution and functional attributes of bat species. We sampled bat communities in areas with high (three sites) and low (three sites) forest land use management practices including six mist-netting locations in order to sample for bats at each site. In addition, we have also measured temperature, humidity, percentage of land use coverage (managed forest, agriculture, and native forest), and percentage of canopy openness at each site. We captured 87 bats belonging to eight species representing two families: Phyllostomidae and Vespertilionidae. For the functional analysis, we used three functional attributes to describe wing morphology: wing loading, aspect ratio, and forearm length. No significant effect of any environmental variable was observed on bat species composition. However, bat species distribution was driven by the ability associated with their functional attributes to occupy the space. Moreover, forearm length was positively correlated with forest cover, canopy openness, and humidity. Species with similar wing morphology have responded in a similar way to environmental variables in the studied areas. Functional dispersion was high in the native forest. The monoculture of exotic species may increase the functional attributes related with vulnerability as described by bat wing morphology. Therefore, the native forest conversion to pine forest monoculture may increase the loss of functional attributes in the bat community.

Nonbreeding season ecology and behavior of Eastern Towhees (Pipilo erythropthalmus)

Eastern Towhees (Pipilo erythropthalmus) are partial migrants that inhabit dense thickets of shrubs in both breeding and nonbreeding seasons and have declined range-wide by approximately 50% since the mid-1960s. Few studies have addressed the nonbreeding season natural history of Eastern Towhees. The objectives of our study were to (1) describe and quantify nonbreeding habitat use and social interactions, and (2) relate these metrics to winter weather conditions. We captured and radio-tagged 9 Eastern Towhees and tracked them using homing and triangulation for a total of 528 locations from late November 2015 to March 2016, plus 3 Eastern Towhees tracked in 2014–2015. The mean (± SE) home range size (80% kernel isopleth) was 7.31 ± 0.22 ha, and the mean (± SE) core area (30% kernel isopleth) was 1.52 ± 0.94 ha. The mean overlap of home ranges between neighbors was 36%, and 24% between neighboring core areas. The study area was classified into 4 habitats: mowed, blackberry scrub, woody shrub, and wooded. Habitat use did not directly correspond with availability: Eastern Towhees occupied woody shrub habitat most (48% of locations vs. 35% of available habitat), suggesting that of our 4 habitat types, woody shrub was preferred. For weather, wind speed did not significantly affect habitat use, foraging method, vocalizations, or flock size. Although temperature did not significantly affect any of the behaviors, there were trends for less ground foraging and more use of wooded habitat in freezing temperatures. Snow cover influenced habitat use (odds ratio = 0.60), vocalizations (odds ratio = 1.77), and flock size (odds ratio = 1.97), but not foraging. These results contribute to understanding the nonbreeding natural history of Eastern Towhees and demonstrate that inclement weather in the nonbreeding season may influence habitat use and behaviors in ways that could affect nonbreeding season survival.

Factors Influencing Habitat Use by Owls in a Mosaic Landscape in the Garo Hills, Northeast India

Northeast India, located in a global biodiversity hotspot, faces several biodiversity issues. These include shorter fallow periods between ‘jhum’ (shifting cultivation) cycles which give less time for forests to recoup, along with encroachment, logging and other developmental activities. This is leading to widespread habitat loss and degradation. In such a scenario, Community Reserves that largely make up the Protected Area network in Northeast India could likely act as refugia for several species. Our study explored how owls use these Reserves in the Garo Hills in Meghalaya. We conducted three temporal replicates in thirty-three 500 × 500 m grids between January and March 2020. Ecologically relevant site and sampling covariates were quantified in each grid along with owl counts. Occupancy and N-mixture models revealed that wind speed, temperature, humidity and survey start time had the greatest effect on the detection probability of owls. On the other hand, occupancy and abundance were most influenced by slope, distance to water body, disturbance and tree structural characteristics (girth and tree height heterogeneity). With these findings, we highlight the importance of preserving water bodies and old-growth forests in Community Reserves of the Garo Hills landscape, which seem to be acting as refugia for the Brown Wood-owl Strix leptogrammica, an old-growth forest specialist thought to be currently in decline.

Resource utilisation by smooth-coated otter in the rivers of Himalayan foothills in Uttarakhand, India

Conservation depends on acquiring timely knowledge on species’ ecology to alleviate the risks of biodiversity loss driven by anthropogenic stressors. Himalayan freshwater ecosystems are exceedingly threatened by the compounding effects of rising developmental pressure and climate change, jeopardizing biodiversity nested within this imperilled landscape. Riverine ecosystems of the Himalayan foothill forests of India are a stronghold of the vulnerable smooth-coated otter populations. This study entails the understanding of resource utilisation by the smooth-coated otter ( Lutrogale perspicillata ) in terms of habitat use and dietary composition in seven rivers along the Himalayan foothills in India. We surveyed 121.09 km of rivers for otter signs and associated habitat variables. Using Generalised Linear Models, we assessed the factors influencing otter habitat use. We estimated the relative abundance and catch per unit effort of fish species and evaluated otter diet based on spraint samples ( n = 120) using frequency of occurrence and score-bulk estimate methods. Habitat use by otters is governed by a combination of habitat components, which are intricately linked to different requirements such as feeding, grooming, and denning. We found that habitat use was positively associated with channel depth, moderate vegetation, and bank substrate types – bedrock, boulders, sand, and grass. Whereas, increasing distance to escape cover, sparse vegetation, channel width, and anthropogenic disturbance negatively influenced habitat use. Dietary analyses revealed that relatively abundant fish species viz. , Tor putitora and Barilius vagra , predominated the diet of otters. Echoing the principles of optimal foraging theory, our results indicated that small-medium sized fishes of the size range 79.05–199.92 mm, were consumed more often, and larger fishes (> 263.24 mm) were consumed opportunistically. Our findings provide important conservation insights on the status of the smooth-coated otter, their interactions with different habitat components, and dietary spectrum in rivers of the Himalayan foothills. Overall, our study gives cognizance to the importance of preserving freshwater and riparian habitats to ensure the persistence of otters and their prey in the region.

Grasslands half‐full: investigating drivers of spatial heterogeneity in ungulate occurrence in Indian Terai

AbstractGrassland ecosystems have declined in their extent globally, driving declines in wild ungulate populations. Even within the remnant grasslands, ungulate distribution is highly heterogeneous for reasons that are not well understood. This in turn undermines both local and landscape level conservation efforts for these often‐neglected ecosystems and the herbivores they support. We investigated grassland‐ungulate relationships in the Terai region of North India, where wild ungulates are patchily distributed across alluvial grasslands, a besieged ecosystem. Specifically, we posited that spatial variation in grassland habitat use by swamp deer (Rucervus duvaucelii duvaucelii), hog deer (Axis porcinus) and spotted deer (Axis axis) would be explained by community composition, palatability of key grasses, and fire and flooding regimes in grasslands. Hierarchical clustering and multivariate ordination revealed that three dominant tall‐grass communities and the narrowly distributed and more palatable short grass Cynodon‐Oryza community were only marginally influenced by fire and flood histories. Ungulate habitat use, assessed using occupancy models for spatially correlated data, indicated that hog deer were ubiquitously distributed across the grasslands in the park (habitat use probability, ᴪ = 0.92, se = 0.05) utilizing a diverse range of grassland types, while spotted deer (ᴪ = 0.80, se = 0.17) and swamp deer (ᴪ = 0.45, se = 0.10) occurrence within grasslands was relatively lower. Grass height and grassland extent positively influenced habitat use of swamp deer and spotted deer, respectively. However, grassland community composition, fire history, flood history and palatability were relatively uninformative predictors of fine‐scale habitat use. Our study provides a robust baseline for future monitoring of grasslands and ungulates as well as insights for the design and implementation of grassland management interventions.

Investigation of Environmentally Dependent Movement of Bottlenose Dolphins (Tursiops truncatus)

How environmental features (e.g., people, enrichment, or other animals) affect movement is an important element for the study of animal behavior, biomechanics, and welfare. Here we present a stationary overhead camera-based persistent monitoring framework for the investigation of bottlenose dolphin (Tursiops truncatus) response to environmental stimuli. Mask R-CNN, a convolutional neural network architecture, was trained to automatically detect 3 object types in the environment: dolphins, people, and enrichment floats that were introduced to stimulate and engage the animals. Detected objects within each video frame were linked together to create track segments across frames. The animals’ tracks were used to parameterize their response to the presence of environmental stimuli. We collected and analyzed data from 24 sessions from bottlenose dolphins in a managed lagoon environment. The seasons had an average duration of 1 h and around half of them had enrichment (42%) while the rest (58%) did not. People were visible in the environment for 18.8% of the total time (∼4.5 h), more often when enrichment was present (∼3 h) than without (∼1.5 h). When neither enrichment nor people were present, the animals swam at an average speed of 1.2 m/s. When enrichment was added to the lagoon, average swimming speed decreased to 1.0 m/s and the animals spent more time moving at slow speeds around the enrichment. Animals’ engagement with the enrichment also decreased over time. These results indicate that the presence of enrichment and people in, or around, the environment attracts the animals, influencing habitat use and movement patterns as a result. This work demonstrates the ability of the proposed framework for the quantification and persistent monitoring of bottlenose dolphins’ movement, and will enable new studies to investigate individual and group animal locomotion and behavior.

Habitat Use and Selection by the Collared Forest-Falcon (Micrastur semitorquatus) in the Tropical Rainforest of Los Tuxtlas Biosphere Reserve, Mexico

The availability of habitat determines patterns of habitat use and selection by raptors, and habitat loss in human-modified landscapes may influence habitat use by individual raptors. This is important for tropical forest-dependent species, which face an accelerated rate of habitat loss worldwide. I evaluated habitat use and selection by Collared Forest-Falcons (Micrastur semitorquatus) in the fragmented rainforest of the Los Tuxtlas Biosphere Reserve, state of Veracruz, Mexico. I conducted vantage point and transect observations combined with playbacks to survey Collared Forest-Falcons in March–June 2012 and 2013. I estimated habitat use and selection by forest falcons that inhabit low forest-cover and high forest-cover landscapes. In general, Collared Forest-Falcons selected primary forest and included higher proportions of this habitat within their territories and core areas. Even though the falcons avoided cattle pastures, individuals inhabiting low forest-cover landscapes included a higher proportion of this land cover within their territories, probably as a response to low forest availability in the landscape. Results from this study demonstrate that Collared Forest-Falcons preferentially selected primary rain forests but also used secondary forests in Los Tuxtlas Biosphere Reserve. Low forest-cover in the landscape may be influencing habitat use patterns of falcons, forcing them to use a higher amount of the suboptimal habitat, and increasing their risk of mortality with potential consequences for population dynamics.