Habitat Selection In Response Research Articles

Carnivore space use behaviors reveal variation in responses to human land modification

BackgroundSpatial behavior, including home-ranging behaviors, habitat selection, and movement, can be extremely informative in estimating how animals respond to landscape heterogeneity. Responses in these spatial behaviors to features such as human land modification and resources can highlight a species’ spatial strategy to maximize fitness and minimize mortality. These strategies can vary on spatial, temporal, and individual scales, and the combination of behaviors on these scales can lead to very different strategies among species.MethodsHarnessing the variation present at these scales, we characterized how species may respond to stimuli in their environments ranging from broad- to fine-scale spatial responses to human modification in their environment. Using 15 bobcat-years and 31 coyote-years of GPS data from individuals inhabiting a landscape encompassing a range of human land modification, we evaluated the complexity of both species’ responses to human modification on the landscape through their home range size, habitat selection, and functional response behaviors, accounting for annual, seasonal, and diel variation.ResultsBobcats and coyotes used different strategies in response to human modification in their home ranges, with bobcats broadly expanding their home range with increases in human modification and displaying temporal consistency in functional response in habitat selection across both season and time of day. Meanwhile, coyotes did not expand their home ranges with increased human modification, but instead demonstrated fine-scale responses to human modification with habitat selection strategies that sometimes varied by time of day and season, paired with functional responses in selection behaviors.ConclusionsThese differences in response to habitat, resources, and human modification between the two species highlighted the variation in spatial behaviors animals can use to exist in anthropogenic environments. Categorizing animal spatial behavior based on these spatiotemporal responses and individual variation can help in predicting how a species will respond to future change based on their current spatial behavior.

Functional responses in habitat selection as a management tool to evaluate agri-environment schemes for farmland birds

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

Revealing functional responses in habitat selection of rocky features and rugged terrain by Eurasian lynx (Lynx lynx) using LiDAR data

ContextMany carnivores are attracted to rugged terrain, rocky areas, and conspicuous relief features. However, most of the previous research is limited to general topographical habitat characteristics and rarely consider the effects of microhabitat characteristics.ObjectivesWe used the Eurasian lynx (Lynx lynx) as a model species to investigate the effects of microhabitat characteristics and human infrastructure on habitat selection. We also tested whether there is evidence for a functional response in habitat selection across a large gradient of habitat availability.MethodsWe developed a new approach for detecting rocky outcrops from airborne LiDAR data. In combination with other remote sensing techniques and GPS-telemetry data, we assessed lynx habitat selection and functional responses across two geologically contrasting areas in Europe.ResultsWe detected > 1 million rocky outcrops and confirmed their strong selection by lynx. Lynx also selected steep, rugged, and rocky areas, especially for day-resting sites. Furthermore, lynx avoided paths during the day but selected them and other linear anthropogenic infrastructure during the night, indicating the behaviour-specific impact of human infrastructure. We also observed a functional response in the selection of rocky and rugged areas, as lynx’ selection of such habitats increased with their lower availability. This highlights the importance of preserving such terrains, especially when they are rare in a landscape.ConclusionsOur results highlight the importance of incorporating remote sensing techniques and data on microhabitat features in animal habitat selection research. We also recommend caution when developing new infrastructure for human recreation or promoting its use near geomorphological features and in rugged terrain.

Functional responses in American marten habitat selection indicate cumulative effects of progressive habitat change

AbstractShifts in habitat selection may serve as behavioral indicators of changing habitat quality and can provide an insight into the effects of chronic disturbance on wildlife populations before rates of occurrence and other metrics related to population viability are affected. Long‐term studies can provide unique opportunities to understand animals' behavioral responses to the cumulative effects of habitat disturbance that may be missed by short‐term studies or space‐for‐time substitution. Using the American marten (Martes americana) as a focal species, we evaluated the effects of progressive habitat disturbance on an animal population by identifying changes in habitat availability and selection over time. Marten are strongly associated with mature forest conditions and are thus sensitive to forest harvesting, which is a chronic and prevalent form of disturbance across the species' range. We developed resource selection functions that characterized both temporally consistent patterns and functional responses in the relative selection of habitats by marten at the patch scale. We used a combination of marten location data collected during three periods over 30 years of extensive forest change in northern Maine and a habitat classification scheme informed by species' behavior and designed to capture habitat changes over time. Marten increased their selection of tall (>12 m mean tree height) mature forest, including uncut forest and regenerated clearcuts, in response to decreased availability. Marten also increased avoidance of early‐successional forest (<9 m mean tree height) in response to increased availability. These functional responses in habitat selection appear to enable marten to maintain access to required resources in mature forest and limit exposure to risky or resource‐poor habitat within home ranges. However, a declining trend in the occurrence of resident adult females may indicate a limit to the functional response strategies for individuals unable to incur the energetic or prey‐related costs that may be associated with strong functional responses. Our results suggest that, despite adaptive habitat selection strategies, there are minimum thresholds of mature forest availability below which resident adults, particularly females, will struggle to persist. We recommend forest management strategies targeted at minimizing the strength of functional responses displayed by marten within occupied landscapes.

Ocelots in the moonlight: Influence of lunar phase on habitat selection and movement of two sympatric felids.

Various landscape and environmental factors influence animal movement and habitat selection. Lunar illumination affects nocturnal visual perception of many species and, consequently, may influence animal activity and habitat selection. However, the effects of varying moon stage may differ across taxa. Prey species often reduce activity during highly visible periods of night while predators may increase activity or alter their habitat use. Ocelots (Leopardus pardalis) and bobcats (Lynx rufus), two nocturnal predatory felids that coexist in southern Texas, may also alter their behavior in response to the phase of the moon. To evaluate the effects of lunar phase on habitat selection of ocelots and bobcats, we executed a step selection analysis using high-frequency GPS-telemetry data collected on each species (ocelot, N = 8; bobcat, N = 13) in southern Texas during 2017-2021 and compared step length during new versus full moons. We predicted that ocelots would increase use of dense thornshrub to reduce their visibility during a full moon. However, as bobcats are habitat generalists and are more active during crepuscular periods, we predicted less influence of moon phase on activity. Ocelots did not alter habitat selection in response to lunar phase but moved shorter distances during full moon phases. Conversely, bobcats selected for greater vegetation cover during full moons, possibly to facilitate hunting during brighter periods, but exhibited no difference in movement across lunar phase. We provide, to our knowledge, the first example of habitat selection by predators in relation to lunar phase and show differences across new versus full moons by ocelots and bobcats such that ocelots alter step length but not habitat selection while bobcats altered habitat selection but not step length in response to shifting lunar phase. Further, we suggest the high potential for ocelot-vehicle collisions on darker nights due to increased movement by ocelots and poor visibility for drivers.

Female treefrog preference for breeding sites matches offspring performance in the presence of two anuran competitors.

Preference-performance theory predicts that females should select breeding sites that maximize offspring performance. Amphibians have been a model system for investigating habitat selection, yet most studies have focused on habitat selection in response to predators and conspecifics. We investigated female oviposition site selection and larval performance in eastern gray treefrogs (Hyla versicolor) among pools with and without one of two ecologically distinct heterospecific larvae, the green frog (Rana clamitans) and the American bullfrog (R. catesbeiana). Pools without heterospecifics were used on more nights and had more eggs deposited compared to pools with heterospecifics. In a competition experiment, treefrog larval performance matched this female preference: tadpoles developed faster and grew larger in the absence of either heterospecific. Although we hypothesized that bullfrogs would more strongly affect female treefrog preference and offspring performance because of previous work demonstrating that bullfrogs have stronger negative effects on other tadpoles, both heterospecifics elicited similar responses. The effects of heterospecifics on anuran breeding site selection are understudied and not well understood, and our results demonstrate that female selection of breeding sites is an adaptive behavior for offspring in the presence of heterospecific competitors.

A life-history spectrum of population responses to simultaneous change in climate and land use.

Climate and land use change are two of the primary threats to global biodiversity; however, each species within a community may respond differently to these facets of global change. Although it is typically assumed that species use the habitat that is advantageous for survival and reproduction, anthropogenic changes to the environment can create ecological traps, making it critical to assess both habitat selection (e.g. where species congregate on the landscape) and the influence of selected habitats on the demographic processes that govern population dynamics. We used a long-term (1958-2011), large-scale, multi-species dataset for waterfowl that spans the United States and Canada to estimate species-specific responses to climate and land use variables in a landscape that has undergone significant environmental change across space and time. We first estimated the effects of change in climate and land use variables on habitat selection and population dynamics for nine species. We then hypothesized that species-specific responses to environmental change would scale with life-history traits, specifically: longevity, nesting phenology and female breeding site fidelity. We observed species-level heterogeneity in the demographic and habitat selection responses to climate and land use change, which would complicate community-level habitat management. Our work highlights the importance of multi-species monitoring and community-level analysis, even among closely related species. We detected several relationships between life-history traits, particularly nesting phenology, and species' responses to environmental change. One species, the early-nesting northern pintail (Anas acuta), was consistently at the extreme end of responses to land use and climate predictors and has been a species of conservation concern since their population began to decline in the 1980s. They, and the blue-winged teal, also demonstrated a positive habitat selection response to the proportion of cropland on the landscape that simultaneously reduced abundance the following year, indicative of susceptibility to ecological traps. By distilling the diversity of species' responses to environmental change within a community, our methodological approach and findings will help improve predictions of community responses to global change and can inform multi-species management and conservation plans in dynamic landscapes that are based on simple tenets of life-history theory.

Evolutionary Tuning of Transient Receptor Potential Ankyrin 1 Underlies the Variation in Heat Avoidance Behaviors among Frog Species Inhabiting Diverse Thermal Niches.

Environmental temperature is a critical factor for all forms of life, and thermal tolerance defines the habitats utilized by a species. Moreover, the evolutionary tuning of thermal perception can also play a key role in habitat selection. Yet, the relative importance of thermal tolerance and perception in environmental adaptation remains poorly understood. Thermal conditions experienced by anuran tadpoles differ among species due to the variation in breeding seasons and water environments selected by parental frogs. In the present study, heat tolerance and avoidance temperatures were compared in tadpoles from five anuran species that spatially and temporally inhabit different thermal niches. These two parameters were positively correlated with each other and were consistent with the thermal conditions of habitats. The species difference in avoidance temperature was 2.6 times larger than that in heat tolerance, suggesting the importance of heat avoidance responses in habitat selection. In addition, the avoidance temperature increased after warm acclimation, especially in the species frequently exposed to heat in their habitats. Characterization of the heat-sensing transient receptor potential ankyrin 1 (TRPA1) ion channel revealed an amphibian-specific alternatively spliced variant containing a single valine insertion relative to the canonical alternative spliced variant of TRPA1, and this novel variant altered the response to thermal stimuli. The two alternatively spliced variants of TRPA1 exhibited different thermal responses in a species-specific manner, which are likely to be associated with a difference in avoidance temperatures among species. Together, our findings suggest that the functional change in TRPA1 plays a crucial role in thermal adaptation processes.

Risky business: How an herbivore navigates spatiotemporal aspects of risk from competitors and predators.

Understanding factors that influence animal behavior is central to ecology. Basic principles of animal ecology imply that individuals should seek to maximize survival and reproduction, which means carefully weighing risk against reward. Decisions become increasingly complex and constrained, however, when risk is spatiotemporally variable. We advance a growing body of work in predator-prey behavior by evaluating novel questions where a prey species is confronted with multiple predators and a potential competitor. We tested how fine-scale behavior of female mule deer (Odocoileus hemionus) during the reproductive season shifted depending upon spatial and temporal variation in risk from predators and a potential competitor. We expected female deer to avoid areas of high risk when movement activity of predators and a competitor were high. We used GPS data collected from 76 adult female mule deer, 35 adult female elk, 33 adult coyotes, and six adult mountain lions. Counter to our expectations, female deer exhibited selection for multiple risk factors, however, selection for risk was dampened by the exposure to risk within home ranges of female deer, producing a functional response in habitat selection. Furthermore, temporal variation in movement activity of predators and elk across the diel cycle did not result in a shift in movement activity by female deer. Instead, the average level of risk within their home range was the predominant factor modulating the response to risk by female deer. Our results counter prevailing hypotheses of how large herbivores navigate risky landscapes and emphasize the importance of accounting for the local environment when identifying effects of risk on animal behavior. Moreover, our findings highlight additional behavioral mechanisms used by large herbivores to mitigate multiple sources of predation and potential competitive interactions.

Black bear spatial responses to the Wallow Wildfire in Arizona

AbstractThe Wallow Fire, the largest wildfire in Arizona history, encompassed 2,170 km2 and provided a rare opportunity to examine habitat selection and home ranges of American black bears (Ursus americanus) before and after a wildfire. We had fitted global positioning system (GPS) collars on 47 bears from 2005 to April 2011, and 10 of these were still collared when the fire started in May 2011. We captured and collared an additional 7 black bears within the fire perimeter post‐fire (Jul–Sep 2011 and Jun 2012). To evaluate how black bears were affected by the fire, we fit a step selection function using a conditional mixed effects Poisson regression model to estimate the relative strength of black bear habitat selection in response to burn severity. Additionally, we estimated home range sizes using an autocorrelated kernel density estimator by means of a continuous‐time movement model. We then used a generalized linear model with a negative binomial error distribution and mixed effects to estimate the effect of the burn severity on black bear home range size, while controlling for sex and drought. In spring and summer in years prior to the fire, bears selected areas that later burned in the fire. After the fire, bears used all burn severities, but their selection for high‐severity burns decreased significantly in summer 2011 and fall 2012. Home range sizes were 3.06 times larger pre‐fire than post‐fire. Our study demonstrates that black bears continued to use all burn severities after a major wildfire, and that post‐fire conditions did not result in expanded black bear home ranges.

Individual differences in habitat selection mediate landscape level predictions of a functional response.

Predicting future space use by animals requires models that consider both habitat availability and individual differences in habitat selection. The functional response in habitat selection posits animals adjust their habitat selection to availability, but population-level responses to availability may differ from individual responses. Generalized functional response (GFR) models account for functional responses by including fixed effect interactions between habitat availability and selection. Population-level resource selection functions instead account for individual selection responses to availability with random effects. We compared predictive performance of both approaches using a functional response in elk (Cervus canadensis) selection for mixed forest in response to road proximity, and avoidance of roads in response to mixed forest availability. We also investigated how performance changed when individuals responded differently to availability from the rest of the population. Individual variation in road avoidance decreased performance of both models (random effects: β = 0.69, 95% CI 0.47, 0.91; GFR: β = 0.38, 95% CI 0.05, 0.71). Changes in individual road and forest availability affected performance of neither model, suggesting individual responses to availability different from the functional response mediated performance. We also found that overall, both models performed similarly for predicting mixed forest selection (F1, 58 = 0.14, p = 0.71) and road avoidance (F1, 58 = 0.28, p = 0.60). GFR estimates were slightly better, but its larger number of covariates produced greater variance than the random effects model. Given this bias-variance trade-off, we conclude that neither model performs better for future space use predictions.

Specialization directs habitat selection responses to a top predator in semiaquatic but not aquatic taxa

Habitat selectivity has become an increasingly acknowledged mechanism shaping the structure of freshwater communities; however, most studies have focused on the effect of predators and competitors, neglecting habitat complexity and specialization. In this study, we examined the habitat selection of semiaquatic (amphibians: Bufonidae; odonates: Libellulidae) and aquatic organisms (true bugs: Notonectidae; diving beetles: Dytiscidae). From each family, we selected one habitat generalist species able to coexist with fish (Bufo bufo, Sympetrum sanguineum, Notonecta glauca, Dytiscus marginalis) and one species specialized in fishless habitats (Bufotes viridis, Sympetrum danae, Notonecta obliqua, Acilius sulcatus). In a mesocosm experiment, we quantified habitat selection decisions in response to the non-consumptive presence of fish (Carassius auratus) and vegetation structure mimicking different successional stages of aquatic habitats (no macrophytes; submerged and floating macrophytes; submerged, floating, and littoral-emergent macrophytes). No congruence between habitat specialists and generalists was observed, but a similar response to fish and vegetation structure defined both semiaquatic and aquatic organisms. While semiaquatic generalists did not distinguish between fish and fishless pools, specialists avoided fish-occupied pools and had a preferred vegetation structure. In aquatic taxa, predator presence affected habitat selection only in combination with vegetation structure, and all species preferred fishless pools with floating and submerged macrophytes. Fish presence triggered avoidance only in the generalist bug N. glauca. Our results highlight the significance of habitat selectivity for structuring freshwater ecosystems and illustrate how habitat selection responses to a top predator are dictated by specialization and life history.

Holling meets habitat selection: functional response of large herbivores revisited

BackgroundHolling (Can Entomol 91(5):293–320, 1959) was the first to describe a functional response between a predator’s consumption-rate and the density of its prey. The same concept can be applied to the habitat selection of herbivores, specifically, the change in relative habitat use with the change in habitat availability. Functional responses in habitat selection at a home-range scale have been reported for several large herbivores. However, a link to Holling’s original functional response types has never been drawn, although it could replace the current phenomenological view with a more mechanistically based understanding of functional responses.MethodsIn this study, discrete choice models were implemented as mixed-effects baseline-category logit models to analyze the variation in habitat selection of a large herbivore at seasonal and diurnal scales. Thus, changes in the use of land cover types with respect to their availability were investigated by monitoring 11 land cover types commonly used by roe deer (Capreolus capreolus) in the Bavarian Forest National Park, Germany. Functional response curves were then fitted using Holling’s formulas.ResultsStrong evidence of non-linear functional responses was obtained for almost all of the examined land cover types. The shape of the functional response curves varied depending on the season, the time of day, and in some cases between sexes. These responses could be referenced to Holling’s types, with a predominance of type II.ConclusionsOur results indicate that Holling’s types can be applied to describe general patterns of the habitat selection behavior of herbivores. Functional responses in habitat selection may occur in situations requiring a trade-off in the selection of land cover types offering different resources, such as due to the temporally varying physiological needs of herbivores. Moreover, two associated parameters defining the curves (prey density and predation rate) can aid in the identification of temporal variations and in determinations of the strength of the cost-benefit ratio for a specific land cover type. Application of our novel approach, using Holling’s equations to describe functional responses in the habitat selection of herbivores, will allow the assignment of general land cover attraction values, independent of availability, thus facilitating the identification of suitable habitats.

Complex multi‐predator effects on demographic habitat selection and community assembly in colonizing aquatic insects

AbstractRunning the gauntlet of predators consumes critical time and energy resources, as all species are vulnerable to one or, typically, more predators at some life stage. Prey employ a vast array of mechanisms to avoid predation, and predators, likewise, come in a bewildering variety. Thus, defensive adaptations are rarely one size fits all. Considerable work has addressed multi‐predator consumptive effects, but we now know that non‐consumptive effects of predators can dramatically impact individuals, (meta)populations, and (meta)communities. However, little is known regarding the community‐wide dynamics of non‐consumptive effects generated by multiple predators. Predator avoidance by choosing a patch that is free of a particular predator or predators can be the most effective strategy if conditions at colonization are a reliable predictor of absence, which is often true for fish in freshwater systems. We experimentally manipulated composition of the predator assemblage in aquatic mesocosms in a substitutive design, with zero, one, two, or three caged predatory fish species (one benthic, one pelagic, and one surface fish) at constant density and biomass, and assayed responses of naturally colonizing aquatic insects. We addressed three related questions; first, how do members of a diverse assemblage of colonizing aquatic insects respond to this variation in species and species combinations, second, do individual species (and higher taxa), respond differently to single vs. multiple predator species (species richness), and third how do any responses to fish species and species combinations, and effects on species richness, translate into community‐wide changes in the composition of colonists. Prey had varied responses to specific predators or combinations of predators, resulting in distinct community composition across treatments and higher β‐diversity with predators. Prey showed emergent multi‐predator effects, where certain species only responded to predator species combinations, but not to any individual predator, and stronger effects of multiple predator vs. single‐predator treatments, despite strong responses to individual predators in many taxa. Habitat selection effects can range from the individual to the metacommunity, and the dynamics of habitat selection in response to predators is a complex function of predator identity, density, richness, species composition, and patch spatial context.

Geographic variation in Culex oviposition habitat selection responses to a predator, Notonecta irrorata

1. Predators have effects on prey populations through both consumptive and non‐consumptive effects. Predator's presence is expected to drive variation in prey oviposition habitat selection behaviour, but differences in biotic and abiotic characteristics of habitats, or trait variation, may produce geographic variation in species interactions.2. We conducted a series of experiments in two geographic locations, Mississippi and Missouri, USA, to assess oviposition responses of Culex mosquitoes (prey) to the presence of Notonecta irrorata (predator). We first tested whether mosquitoes in each location respond to the presence of N. irrorata, with follow‐up experiments to determine whether mosquitoes respond to variation in N. irrorata density, whether N. irrorata from each location generate different responses by the same Culex population, and whether diet and consumption of conspecifics affect oviposition.3. We found that Culex restuans in Missouri had reduced oviposition when N. irrorata were present. In Mississippi, C. restuans did not respond to the presence of N. irrorata from either Mississippi or Missouri, to the variation in density of N. irrorata, or to N. irrorata that had been fed larval mosquitoes.4. Our study documents the first instance of geographic variation in oviposition response of a prey species to a predator species.

Disease or drought: environmental fluctuations release zebra from a potential pathogen-triggered ecological trap.

When a transmission hotspot for an environmentally persistent pathogen establishes in otherwise high-quality habitat, the disease may exert a strong impact on a host population. However, fluctuating environmental conditions lead to heterogeneity in habitat quality and animal habitat preference, which may interrupt the overlap between selected and risky habitats. We evaluated spatio-temporal patterns in anthrax mortalities in a plains zebra (Equus quagga) population in Etosha National Park, Namibia, incorporating remote-sensing and host telemetry data. A higher proportion of anthrax mortalities of herbivores was detected in open habitats than in other habitat types. Resource selection functions showed that the zebra population shifted habitat selection in response to changes in rainfall and vegetation productivity. Average to high rainfall years supported larger anthrax outbreaks, with animals congregating in preferred open habitats, while a severe drought forced animals into otherwise less preferred habitats, leading to few anthrax mortalities. Thus, the timing of anthrax outbreaks was congruent with preference for open plains habitats and a corresponding increase in pathogen exposure. Given shifts in habitat preference, the overlap in high-quality habitat and high-risk habitat is intermittent, reducing the adverse consequences for the population.

Positive responses from giant pandas to the Natural Forest Conservation Programme based on slope utilisation

Suitable habitats contain essential resources for individuals completing their life cycles. However, timber harvesting can alter habitat structure and affect animal habitat selection patterns. Several recent conservation initiatives conducive to the restoration of giant panda habitat, such as the National Forest Conservation Program (NFCP) in China, have been implemented. Relatively few studies have concentrated on the effects of the NFCP on habitat selection by giant pandas. Extensive datasets, collected from the 3rd (1999–2002) and 4th (2011–2014) national giant panda surveys in Sichuan province, China, were analysed to reveal responses in habitat selection by giant pandas with implementation of the NFCP. The results confirm that more, larger trees stood in original forests than in secondary forests. With the cessation of timber harvesting and implementation of NFCP, gentle sloping areas of secondary growth forests in mountainous ranges were again occupied by giant pandas during the 4th survey. Under the impacts of timber harvesting, there was a threshold effect of slope utilisation by the giant pandas. Based on comparisons of the variation in habitat selection from the 3rd to the 4th survey between the old-growth and secondary forests, more and more pandas have been migrating into the gentle slope areas of secondary growth forests during restoration of the pandas’ habitat. Whether the balance in migration patterns is or is not reached can be used as an evaluation criterion of restoring panda habitat to original forest. These results suggested a positive response by giant pandas to the NFCP based on slope utilisation in recent decades. However, more work also needs to focus on panda habitat restoration in secondary growth forest in future, such as strengthening habitat management policies, prolonging the NFCP, increasing investment in panda habitat restoration technology, and so forth.

Prey and habitat distribution are not enough to explain predator habitat selection: addressing intraspecific interactions, behavioural state and time

BackgroundMovements and habitat selection of predators shape ecological communities by determining the spatiotemporal distribution of predation risk. Although intraspecific interactions associated to territoriality and parental care are involved in predator habitat selection, few studies have addressed their effects simultaneously with those of prey and habitat distribution. Moreover, individuals require behavioural and temporal flexibility in their movement decisions to meet various motivations in a heterogeneous environment. To untangle the relative importance of ecological determinants of predator fine-scale habitat selection, we studied simultaneously several spatial, temporal, and behavioural predictors of habitat selection in territorial arctic foxes (Vulpes lagopus) living within a Greater snow goose (Anser caerulescens atlantica) colony during the reproductive season.MethodsUsing GPS locations collected at 4-min intervals and behavioural state classification (active and resting), we quantified how foxes modulate state-specific habitat selection in response to territory edges, den proximity, prey distribution, and habitats. We also assessed whether foxes varied their habitat selection in response to an important phenological transition marked by decreasing prey availability (goose egg hatching) and decreasing den dependency (emancipation of cubs).ResultsMultiple factors simultaneously played a key role in driving habitat selection, and their relative strength differed with respect to the behavioural state and study period. Foxes avoided territory edges, and reproductive individuals selected den proximity before the phenological transition. Higher goose nest density was selected when foxes were active but avoided when resting, and was less selected after egg hatching. Selection for tundra habitats also varied through the summer, but effects were not consistent.ConclusionsWe conclude that constraints imposed by intraspecific interactions can play, relative to prey distribution and habitat characteristics, an important role in the habitat selection of a keystone predator. Our results highlight the benefits of considering behavioural state and seasonal phenology when assessing the flexibility of predator habitat selection. Our findings indicate that considering intraspecific interactions is essential to understand predator space use, and suggest that using predator habitat selection to advance community ecology requires an explicit assessment of the social context in which movements occur.

Changes to spotted turtle (Clemmys guttata) habitat selection in response to a salt marsh restoration

Development of coastal New England has led to the replacement of up to 37% of salt marshes with degraded freshwater wetlands, primarily through tidal restrictions. Removing these restrictions to restore salt marsh ecology would improve water quality, increase flood and storm protection, nutrient filtration, erosion control, and carbon sequestration. However, such restorations replace functional freshwater wetlands and could potentially impact freshwater species. Freshwater-dependent wildlife species such as the spotted turtle (Clemmys guttata), may be especially vulnerable to rapid changes in habitat resulting from tidal reintroduction due to their high site fidelity and limited ability to disperse quickly. Conservation of genetically and physically isolated spotted turtle populations as well as the restoration of salt marshes to mitigate climate change impacts are both high priorities on Nantucket Island. These two priorities conflicted in a project to restore tidal hydrology to an impounded freshwater marsh known to host a robust spotted turtle population. We evaluated changes to spotted turtle home range size and location and habitat use in response to salt marsh restoration over eight years. Home range size did not change but the location of home ranges shifted into bordering wetlands landward of the tidal salt water influence. Spotted turtles selected remaining freshwater marshes and shrub swamps while avoiding developed land and areas of establishing salt marsh within areas that had previously been high quality habitat. This study suggests prioritizing conservation of wetlands adjacent to planned salt marsh restoration to provide habitat for freshwater species to migrate.

Aquatic beetles influence colonization of disparate taxa in small lentic systems.

Structure of natural communities is shaped by both abiotic characteristics and the ongoing processes of community assembly. Important to this process are the habitat selection behaviors and subsequent survival of colonists, both in the context of temporal changes in the abiotic characteristics and priority effects driven by earlier colonists. Aquatic beetles are prevalent in temporary freshwater systems, form speciose assemblages, and are often early colonists of temporary ponds. While beetles have the potential to influence community structure through post‐colonization interactions (predation and competition), our goal was to determine whether the presence of beetle assemblages (versus patches without beetles) influences the colonization and oviposition of a diverse group of animals in a naturally colonized experimental landscape. We established mesocosms that either contained existing beetle assemblages or contained no beetles and assessed abundances of subsequent colonists. Treefrogs, Hyla chrysoscelis, and mosquitoes, Culex restuans, both deposited fewer eggs in patches containing beetle assemblages, while two beetles, Copelatus glyphicus and Paracymus, colonized those patches at lower rates. One beetle, Helophorus linearis, colonized patches containing beetle assemblages at higher rates, while two beetles, Berosus infuscatus and Tropisternus lateralis, exhibited no colonization differences between treatments. Overall, there were no differences in the assemblage structure or richness of beetles that colonized patches. Our results illustrate the importance of species‐specific habitat selection behavior in determining the species composition of habitat patches, while emphasizing the role of priority effects in influencing patterns of community assembly. Habitat selection in response to abiotic and biotic characteristics of habitat patches can potentially create greater spatiotemporal niche separation among the numerous, often closely related species (phylogenetically and trophically), that can be simultaneously found in similar patches across landscapes.