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At least 55 records · Page 3Linked to original sources
USGS2024

Monitoring questing winter tick abundance on traditional moose hunting lands

An important symbolic and subsistence animal for many Native American Tribes, the moose ( Alces alces ; mos in Algonquin, Penobscot language) has been under consistent threat in the northeastern United States because of winter tick ( Dermacentor albipictus ) parasitism over the past several decades, causing declines in moose populations throughout the region. This decline has raised concern for Tribes and agencies that are invested in moose. Given this concern, it is increasingly important to effectively monitor and develop strategies to manage winter ticks to address consistent population declines of moose due to winter ticks. The Penobscot Nation developed a novel strategy to sample questing winter ticks (i.e., ticks that are actively seeking hosts) using a plot-based sampling protocol that may be suitable for heterogeneous habitats. We deployed this protocol in the northeastern United States in 2022 during the tick questing period (Sep–Dec) on Penobscot Nation sovereign trust lands, the White Mountain National Forest and Umbagog National Wildlife Refuge, and western-central Massachusetts, USA. We analyzed the data using occupancy and N-mixture models. Detection probability peaked during mid-October and tick occupancy and abundance were greatest at sites with intermediate understory vegetation height. The sampling protocol was successful at sampling ticks in Massachusetts, where abundances were expected to be low, indicating that it may be useful for studies planning to monitor winter tick distribution and abundance in areas with sub-optimal moose habitat and where winter tick abundance is expected to be low. This approach may also benefit managers or researchers intending to monitor many species of hard ticks, and where imperfect detection is expected.

Maine, Massachusetts, New Hampshire↗
USGS2011

Seasonal habitat use and selection by grizzly bears in Northern British Columbia

We defined patterns of habitat use and selection by female grizzly bears (Ursus arctos) in the Besa-Prophet watershed of northern British Columbia. We fitted 13 adult females with Geographic Positioning System (GPS) radio-collars and monitored them between 2001 and 2004. We examined patterns of habitat selection by grizzly bears relative to topographical attributes and 3 potential surrogates of food availability: land-cover class, vegetation biomass or quality (as measured by the Normalized Difference Vegetation Index), and selection value for prey species themselves (moose [Alces alces], elk [Cervus elaphus], woodland caribou [Rangifer tarandus]. Stone's sheep [Ovis dalli stonei]). Although vegetation biomass and quality, and selection values for prey were important in seasonal selection by some individual bears, land-cover class, elevation, aspect, and vegetation diversity most influenced patterns of habitat selection across grizzly bears, which rely on availability of plant foods and encounters with ungulate prey. Grizzly bears as a group avoided conifer stands and areas of low vegetation diversity, and selected for burned land-cover classes and high vegetation diversity across seasons. They also selected mid elevations from what was available within seasonal ranges. Quantifying relative use of different attributes helped place selection patterns within the context of the landscape. Grizzly bears used higher elevations (1,595 ± 31 m SE) in spring and lower elevations (1,436 ± 27 m) in fall; the range of average elevations used among individuals was highest (500 m) during the summer. During all seasons, grizzly bears most frequented aspects with high solar gain. Use was distributed across 10 land-cover classes and depended on season. Management and conservation actions must maintain a diverse habitat matrix distributed across a large elevational gradient to ensure persistence of grizzly bears as levels of human access increase in the northern Rocky Mountains.

Northern British Columbia↗
USGS2026

Moose indifferent to canopy loss from forest disturbance by bark beetles

Conifer forests have experienced widespread disturbance following the infestation of bark beetles ( Dendroctonus spp.). Tree mortality and resulting canopy loss have altered forest composition in ways that could affect moose ( Alces alces ), including potential benefits from increased understory forage and drawbacks through the loss of refuge from heat and deep snow. We examined the behavioral response of moose to beetle-killed forest, comparing resource selection before (2005–2006) and after (2015–2017) disturbance in southeast Wyoming, USA. To evaluate selection, we created a land cover classification layer at 0.5-m resolution using machine learning to delineate dead conifers, as well as aspen and willows that were underrepresented in existing land cover products. By measuring resource selection in a fractional cover framework, we found that moose showed strikingly similar resource selection before and after beetle disturbance. Moose during both periods selected willows and aspen while avoiding conifer forest and shrubs throughout the year. Moose in the post-beetle periods avoided conifer forest more strongly the more conifer forest made up their home range. The same pattern emerged for beetle-killed conifer: the more beetle-kill in a home range, the stronger the avoidance of beetle-kill. Our findings indicate that forest disturbance caused by bark beetles does not appreciably alter habitat quality for moose, and moose continue to employ similar patterns of resource selection regardless of forest changes in the early stages of the post-beetle infestation. Our work supports the importance of riparian and deciduous land cover in sustaining moose populations in the face of widespread forest disturbances.

Wyoming↗
USGS2014

Re-evaluating the northeastern Minnesota moose decline and the role of wolves

We re-evaluated findings from Lenarz et al. (2009) that adult moose ( Alces alces ) survival in northeastern Minnesota was related to high January temperatures and that predation by wolves ( Canis lupus ) played a minor role. We found significant inverse relationships between annual wolf numbers in part of the moose range and various moose demographics from 2003 to 2013 that suggested a stronger role of wolves than heretofore believed. To re-evaluate the temperature findings, we conducted a simulation study, mimicking the approach taken by Lenarz et al. (2009), to explore the potential for concluding a significant relationship exists between temperature and survival, when no association exists. We found that the high R 2 s and low probabilities associated with the regression models in Lenarz et al. (2009) should be viewed cautiously in light of the large number of fitted models (m = 45) and few observations (n = 6 for each of 5 response variables).

Minnesota↗
USGS2026

Life-history stages and behavior influence demographic classification of moose captured on remote cameras

Obtaining accurate information on demographic states, such as the age and sex classes of animals, is an important step for monitoring wildlife populations. Traditionally, demographic data are collected from harvest, aerial surveys and telemetry studies. However, these methods can be expensive, limited to small spatial scales, or biased due to human behavior. Remote cameras have become a mainstay for studying and monitoring wildlife as they are relatively inexpensive, can be deployed over large spatial scales, and effort can be accounted for during surveys. For some species, a variety of demographic information, such as sex and age classes, can be obtained from pictures. Moose Alces alces are a photogenic species found across boreal and semi-boreal forests of the Northern Hemisphere. Previous studies have used demographic data from remote cameras to estimate demographic parameters and population dynamics. A primary assumption is that these age and sex classes are accurately classified. However, numerous factors can influence the ability of observers to identify age and sex classes of moose captured on cameras. We used data from 84 cameras from a 3-year period (2021–2024) in northern Maine, USA, to evaluate how temporal, environmental, site-level, and endogenous factors influence observers' ability to classify age and sex classes of moose. Using Bayesian categorical regression models, we found that temporal variability, position and proximity of moose from cameras, and the behavior of moose influenced our ability to identify age and sex classes. This information can be used to decide which periods to use data for population modeling and how to design studies to reduce the amount of uncertainty associated with different age and sex classes. We anticipate that our approach could also be used for other species whose age and sex classes can be differentiated using remote cameras.

Maine↗
USGS2015

Effects of climate and plant phenology on recruitment of moose at the southern extent of their range

Climate plays a fundamental role in limiting the range of a species, is a key factor in the dynamics of large herbivores, and is thought to be involved in declines of moose populations in recent decades. We examined effects of climate and growing-season phenology on recruitment (8–9 months old) of young Shiras moose ( Alces alces shirasi ) over three decades, from 18 herds, across a large geographic area encompassing much of the southern extent of their range. Recruitment declined in 8 of 18 herds during 1980–2009, whereas others did not exhibit a temporal trend (none showed a positive trend). During those three decades, seasonal temperatures increased, spring–summer precipitation decreased, and spring occurred earlier, became shorter in duration, and green-up occurred faster. Recruitment was influenced negatively by warm temperatures during the year before young were born, but only for herds with declining recruitment. Dry spring–summers of the previous year and rapid rates of spring green-up in the year of birth had similar negative influences across declining and stable herds. Those patterns indicate both direct (year t ) and delayed (year t− 1 ) effects of weather and plant phenology on recruitment of young, which we hypothesize was mediated through effects on maternal nutritional condition. Suppressed nutrition could have been induced by (1) increased thermoregulatory costs associated with warming temperatures and (2) shortened duration of availability of high-quality forage in spring. Progressive reductions in net energetic gain for species that are sensitive to climate may continue to hamper individual fitness and population dynamics.

Oecologia↗
USGS2025

Identifying strategies to manage boreal forests: Simulating moose and timber management scenarios at a landscape scale in the face of changing environmental conditions

There are ongoing debates among different stakeholders about which forest and ungulate management strategies will sustain high levels of timber and animal harvest and maintain important ecosystem functions under climate change. Ungulate-forest interactions are complex, including periods where forest regeneration is sensitive to browsing pressure, making it difficult to predict the consequences of a given strategy over time. To aid decision-making, we simulated the impacts of moose browsing on forest succession under 18 different combinations of moose ( Alces alces ) harvest rate levels and forest management scenarios in a boreal forest landscape in southern Sweden given projected changes in forest growth due to climate change. We found that the current management practices are important for sustaining a moose-forest system. Increasing moose harvest rates led to slightly smaller moose populations, larger estimates of landscape carrying capacity, and less biomass removal of Scots pine ( Pinus sylvestris ), a commercially valuable species. However, minor changes in the moose harvest were hardly affecting timber production. Increasing the timber harvest rotation time led to the highest estimates of Scots pine biomass, while thinning younger cohorts lead to the highest estimates of Norway spruce ( Picea abies ) biomass. These changes came without much effect to moose population dynamics. However, the increased broadleaf production scenario had a very large positive effect on total aboveground live biomass of deciduous species and on landscape carrying capacity and moose density. This scenario subsequently resulted in the greatest estimates of biomass removal of Scots pine, highlighting the tradeoffs associated with increased moose production.

European Journal of Forest Research↗
USGS2021

Genome-wide SNP analysis of three moose subspecies at the southern range limit in the contiguous United States

Genome-wide evaluations of genetic diversity and population structure are important for informing management and conservation of trailing-edge populations. North American moose ( Alces alces ) are declining along portions of the southern edge of their range due to disease, species interactions, and marginal habitat, all of which may be exacerbated by climate change. We employed a genotyping by sequencing (GBS) approach in an effort to collect baseline information on the genetic variation of moose inhabiting the species’ southern range periphery in the contiguous United States. We identified 1920 single nucleotide polymorphisms (SNPs) from 155 moose representing three subspecies from five states: A. a. americana (New Hampshire), A. a. andersoni (Minnesota), and A. a. shirasi (Idaho, Montana, and Wyoming). Molecular analyses supported three geographically isolated clusters, congruent with currently recognized subspecies. Additionally, while moderately low genetic diversity was observed, there was little evidence of inbreeding. Results also indicated > 20% shared ancestry proportions between A. a. shirasi samples from northern Montana and A. a. andersoni samples from Minnesota, indicating a putative hybrid zone warranting further investigation. GBS has proven to be a simple and effective method for genome-wide SNP discovery in moose and provides robust data for informing herd management and conservation priorities. With increasing disease, predation, and climate related pressure on range edge moose populations in the United States, the use of SNP data to identify gene flow between subspecies may prove a powerful tool for moose management and recovery, particularly if hybrid moose are more able to adapt.

Conservation Genetics↗
USGS1997

Use of ungulates by Yellowstone grizzly bears Ursus arctos

Previous results of fecal analysis from the Yellowstone area and the known abilities of grizzly bears Ursus arctos to acquire and digest tissue from vertebrates suggested that grizzlies in this ecosystem obtained substantial energy from ungulates. This issue was addressed using observations from radio-marked grizzly bears, 1977–1992. Ungulates potentially contributed the majority of energy required for activity during the non-denning season for both adult female and male grizzlies. Most of this energy (95%) was estimated to come from the largest-bodied ungulate species (elk Cervus elaphus , bison Bison bison , and moose Alces alces ), with greatest proportional contributions by scavenged adult male bison (16%), scavenged calf and yearling elk (10%) and adult female elk that were killed (8%) or scavenged (8%). Grizzlies acquired 30% of total edibles from ungulates by predation, of which 13% (or 4% of the total) came from predation on elk calves. Most scavenging occurred during the spring and was associated with the abundance and relative availability of different types of carrion. Predation and scavenging did not appear to be compensatory. Rather, total consumption of ungulates varied inversely with consumption of whitebark pine Pinus albicaulis seeds. The relative frequency of predation to scavenging increased with ungulate density. Contrary to previous suppositions, neither total ungulate use nor frequency of predation increased during the study, despite large increases in some ungulate populations. As expected by the identified trade-offs, Yellowstone grizzlies seemed to prey selectively upon moose, probably because of their solitary habits and forested surroundings, but otherwise favored vulnerable smaller-bodied ungulates such as elk calves. No predation on adult bison was observed.

Idaho, Montana, Wyoming↗
USGS2001

Conservation endocrinology: A noninvasive tool to understand relationships between carnivore colonization and ecological carrying capacity

Reproductive technology, especially the diagnosis of pregnancy by radioimmunoassay of fecal steroid metabolites, is an important component of captive propagation, but its role in our understanding of ecological interactions and in situ biological restoration has been more limited. Where large herbivores have been 'released' from predation by the extirpation of carnivores, controversy often exists about possible detrimental effects at the ecosystem level A related concern is that the reestablishment of large carnivores may decrease the availability of prey populations for human subsistence. We suggest that pregnancy assays can be a valuable tool to help distinguish between the roles of predation versus food-imposed limitations on population size and their effects on juvenile recruitment in wild species. We explored this issue through analyses of fecal progestagen concentration (FPC) levels to document pregnancy in moose (Alces alces) in the southern Greater Yellowstone Ecosystem, a site where wolves (Canis lupus) and grizzly bears (Ursus arctos) are recolonizing former habitats after an absence of more than 60 years. Pregnancy was clearly discernible (mean FPC for pregnant and nonpregnant females, respectively: 10.60 vs. 2.57 ??g/g; p < 0.0001). Among the potential confounding variables that need to be considered if FPC is applied to ecological and demographic questions are whether baseline values are affected by handling, whether neonate survival has been assessed, and whether sampling efforts are directed at both pregnant and nonpregnant animals. With these issues accounted for, the local moose population experienced juvenile survival rates among the highest in North America. Pregnancy rates, however, dropped from 90% in 1966 to about 75% today, rendering them in the lowest fifteenth percentile among moose populations in North America. Our findings suggest that a relatively low frequency of juvenile moose is not the likely result of predation, and they illustrate how endocrinology can be applied to issues involving reproductive events within an ecological context. They also affirm that noninvasive and generally inexpensive endocrinological procedures will be applicable to understanding interactions between recolonizing predators and prey, an issue that will continue to arise because of global restoration efforts, and to the study of rare ungulates in remote systems where data on reproductive events are difficult to obtain.

Wyoming↗
USGS2016

Ecosystem development on terraces along the Kugururok River, northwest Alaska

Riverside terraces along the Kugururok River in the Noatak National Preserve provided an opportunity to study primary succession, considering general trends that apply across all terraces, and unique events that influence individual terraces. The 30-year-old willow/poplar (Salix spp., Populus balsamifera L.) terrace had no trees taller than 1.5 m; the abundant spruce trees were not tall enough to emerge from the canopy height of the willows and poplars, and moose (Alces alces [Clinton]) browsing limited the canopy height of these plants. The 75-year-old poplar/spruce (Picea glauca [Moench] Voss) terrace had a high density of poplars (> 1000/ha) and low density of spruce (125/ha); heavy browsing by moose reduced the density of poplar by about one-half. The removal of the poplar by moose in this stand resulted in sustained increases in growth of individual spruce trees. The 100-year-old younger spruce/poplar terrace had about twice as many spruce trees (1250/ha) as poplar trees (500/ha), and the spruce trees were larger on average than the poplar trees. In the 220+ year-old older spruce/poplar type, only a few poplars remained (about 25/ha), and the number of spruce trees (600/ha) was only half that of the younger stage, either from lower initial spruce density on this terrace, or increased mortality of spruce. The 240+ year-old spruce type was a second-generation forest, characterized by a high density (1950/ha) of small spruce trees, some of which were tilted, indicating discontinuous permafrost. Plant litterfall mass showed no strong trend with terrace age, although N content of litterfall appeared to decline by about 1/3 in the spruce-dominated stages. Fungal biomass increased with ecosystem age, whereas bacterial biomass and microfauna declined. We found no evidence of declining soil N supply in older stages, but fertilization experiments would be needed to determine if N limitation of productivity changed with ecosystem development. We conclude that the general successional trend of increased spruce dominance is robust for this location, but that unique events play important roles in determining tree densities and the timing of the shift in dominance from poplar to spruce. The arrival of moose in the 1970s accelerated dominance by spruce on young terraces.

Écoscience↗
USGS2016

Reproduction in moose at their southern range limit

Reproduction is a critical fitness component in large herbivores. Biogeographic models predict that populations occurring at the edges of the range may have compromised reproductive rates because of inferior habitat at range peripheries. When reproductive rates are chronically low, ungulate populations may lack the resiliency to rebound quickly after periods of environmental stress, and this effect may be greatest for heat-sensitive organisms at their southern range limit. To assess the demographic vulnerability of moose ( Alces alces ), we studied relationships between reproductive rates, maternal age, and rump fat in the southernmost naturally occurring moose population in North America. For prime-aged moose in our study, pregnancy rates were high (92%), but moose aged < 3 or > 9 years had low pregnancy rates (32% and 38%, respectively). The relationship between rump fat and pregnancy was nonlinear such that a threshold of at least 2mm of rump fat yielded a high probability of being pregnant midwinter. In contrast, among pregnant moose, the probability of both producing a calf and recruiting it until spring increased linearly with rump fat. We also conducted a meta-analysis of pregnancy and twinning rates for adult (≥ 2 years) moose across a latitudinal gradient to compare reproductive rates from our study to other populations in North America. Moose living at southern latitudes tended to have lower reproductive rates than those living in the core of moose range, implying that southern moose populations may be demographically more vulnerable than northern moose populations.

Utah↗
USGS2020

A test of the Niche Variation Hypothesis in a ruminant herbivore

Despite the shared prediction that the width of a population's dietary niche expands as food becomes limiting, the Niche Variation Hypothesis (NVH) and Optimal Foraging Theory (OFT) offer contrasting views about how individuals alter diet selection when food is limited. Classical OFT predicts that dietary preferences do not change as food becomes limiting, so individuals expand their diets as they compensate for a lack of preferred foods. In contrast, the NVH predicts that among-individual variation in cognition, physiology or morphology create functional trade-offs in foraging efficiency, thereby causing individuals to specialize on different subsets of food as food becomes limiting. To evaluate (a) the predictions of the NVH and OFT and (b) evidence for physiological and cognitive-based functional trade-offs, we used DNA microsatellites and metabarcoding to quantify the diet, microbiome and genetic relatedness (a proxy for social learning) of 218 moose Alces alces across six populations that varied in their degree of food limitation. Consistent with both the NVH and OFT, dietary niche breadth increased with food limitation. Increased diet breadth of individuals—rather than increased diet specialization—was strongly correlated with both food limitation and dietary niche breadth of populations, indicating that moose foraged in accordance with OFT. Diets were not constrained by inheritance of the microbiome or inheritance of diet selection, offering support for the little-tested hypothesis that functional trade-offs in food use (or lack thereof) determine whether populations adhere to the predictions of the NVH or OFT. Our results indicate that both the absence of strong functional trade-offs and the digestive physiology of ruminants provide contexts under which populations should forage in accordance with OFT rather than the NVH. Also, because dietary niche width increased with increased food limitation, OFT and the NVH provide theoretical support for the notion that plant–herbivore interaction networks are plastic rather than static, which has important implications for understanding interspecific niche partitioning. Lastly, because population-level dietary niche breadth and calf recruitment are correlated, and because calf recruitment can be a proxy for food limitation, our work demonstrates how diet data can be employed to understand a populations' proximity to carrying capacity.

Colorado, Utah, Wyoming↗
USGS2021

Drivers of site fidelity in ungulates

While the tendency to return to previously visited locations—termed ‘site fidelity’—is common in animals, the cause of this behaviour is not well understood. One hypothesis is that site fidelity is shaped by an animal's environment, such that animals living in landscapes with predictable resources have stronger site fidelity. Site fidelity may also be conditional on the success of animals’ recent visits to that location, and it may become stronger with age as the animal accumulates experience in their landscape. Finally, differences between species, such as the way memory shapes site attractiveness, may interact with environmental drivers to modulate the strength of site fidelity. We compared inter-year site fidelity in 669 individuals across eight ungulate species fitted with GPS collars and occupying a range of environmental conditions in North America and Africa. We used a distance-based index of site fidelity and tested hypothesized drivers of site fidelity using linear mixed effects models, while accounting for variation in annual range size. Mule deer Odocoileus hemionus and moose Alces alces exhibited relatively strong site fidelity, while wildebeest Connochaetes taurinus and barren-ground caribou Rangifer tarandus granti had relatively weak fidelity. Site fidelity was strongest in predictable landscapes where vegetative greening occurred at regular intervals over time (i.e. high temporal contingency). Species differed in their response to spatial heterogeneity in greenness (i.e. spatial constancy). Site fidelity varied seasonally in some species, but remained constant over time in others. Elk employed a ‘win-stay, lose-switch’ strategy, in which successful resource tracking in the springtime resulted in strong site fidelity the following spring. Site fidelity did not vary with age in any species tested. Our results provide support for the environmental hypothesis, particularly that regularity in vegetative phenology shapes the strength of site fidelity at the inter-annual scale. Large unexplained differences in site fidelity suggest that other factors, possibly species-specific differences in attraction to known sites, contribute to variation in the expression of this behaviour. Understanding drivers of variation in site fidelity across groups of organisms living in different environments provides important behavioural context for predicting how animals will respond to environmental change.

Journal of Animal Ecology↗
USGS2022

Using piecewise regression to identify biological phenomena in biotelemetry datasets

1. Technological advances in the field of animal tracking have greatly expanded the potential to remotely monitor animals, opening the door to exploring how animals shift their behavior over time or respond to external stimuli. A wide variety of animal-borne sensors can provide information on an animal’s location, movement characteristics, external environmental conditions, and internal physiological status. 2. Here, we demonstrate how piecewise regression can be used to identify the presence and timing of potential shifts in a variety of biological responses using GPS telemetry and other biologging data streams. Different biological latent states can be inferred by partitioning a time-series into multiple segments based on changes in modeled responses (e.g., their mean, variance, trend, degree of autocorrelation) and specifying a unique model structure for each interval. 3. We provide six example applications highlighting a variety of taxonomic species, data streams, timescales and biological phenomena. These examples include a short-term behavioural response (flee and return) by a trumpeter swan Cygnus buccinator following a GPS collar deployment; remote identification of parturition based on movements by a pregnant moose Alces alces ; a physiological response (spike in heart-rate) in a black bear Ursus americanus to a stressful stimulus(presence of a drone); a mortality event of a trumpeter swan signalled by changes in collar temperature and overall dynamic body acceleration; an unsupervised method for identifying the onset, return, duration and staging use of sandhill crane Antigone canadensis migration; and estimation of the transition between incubation and brood-rearing (i.e. hatching) for a breeding trumpeter swan. 4. We implement analyses using the MCP package in R, which provides functionality for specifying and fitting a wide variety of user-defined model structures in a Bayesian framework and methods for assessing and comparing models using information criteria and cross-validation measures.

Journal of Animal Ecology↗
USGS2026

Space between houses influences movement and habitat selection of ungulates: Width as a novel metric of development

Wildlife often lose access to habitat due to housing development. The magnitude of indirect habitat loss can be conditional on the configuration of individual houses, but commonly used metrics (i.e. density or distance) can overlook the configuration of development. We introduce a novel framework to index the configuration of development based on the width of space between houses and associated structures. We use resource selection functions to assess the degree that GPS-collared elk ( Cervus canadensis ), mule deer ( Odocoileus hemionus ), pronghorn and moose ( Alces alces ) on winter range and on migration routes use space between houses within northwest Wyoming, USA, near the towns of Cody and Jackson. Further, to help inform regulations aiming to promote wildlife movement across a gradient of land uses, we differentiated between individuals residing in primarily rural and exurban areas. Rural populations of elk, mule deer, pronghorn and moose avoided spaces narrower than 2 km and never used spaces narrower than 50 m between houses, whereas exurban populations of elk, mule deer and moose selected for spaces narrower than 2 km but avoided spaces narrower than 50 m. We identified cutoffs in rural and exurban areas where space may become too narrow for most animals to use. Through this metric, managers and policy makers can inform the necessary width to maintain wildlife movement through corridors. Our width metric can be applied to other systems and our workflow is publicly available ( https://wildlifemovetools.org/width-calculator ) so users can estimate the width of space between structures in their focal areas. Synthesis and applications . In rural areas, maintaining spaces between houses >500 m will likely facilitate ungulate movement. To fully conserve functional habitat, such as unimpeded habitat use along migration corridors, maintaining spaces approximately >2.5 km between houses will likely be necessary.

Wyoming↗
USGS2021

Habitat use as indicator of adaptive capacity to climate change

Aim Populations of cold‐adapted species at the trailing edges of geographic ranges are particularly vulnerable to the negative effects of climate change from the combination of exposure to warm temperatures and high sensitivity to heat. Many of these species are predicted to decline under future climate scenarios, but they could persist if they can adapt to warming climates either physiologically or behaviourally. We aim to understand local variation in contemporary habitat use and use this information to identify signs of adaptive capacity. We focus on moose ( Alces alces ), a charismatic species of conservation and public interest. Location The northeastern United States, along the trailing edge of the moose geographic range in North America. Methods We compiled data on occurrences and habitat use of moose from remote cameras and GPS collars across the northeastern United States. We use these data to build habitat suitability models at local and regional spatial scales and then to predict future habitat suitability under climate change. We also use fine‐scale GPS data to model relationships between habitat use and temperature on a daily temporal scale and to predict future habitat use. Results We find that habitat suitability for moose will decline under a range of climate change scenarios. However, moose across the region differ in their use of climatic and habitat space, indicating that they could exhibit adaptive capacity. We also find evidence for behavioural responses to weather, where moose increase their use of forested wetland habitats in warmer places and/or times. Main conclusionsOur results suggest that there will be significant shifts in moose distribution due to climate change. However, if there is spatial variation in thermal tolerance, trailing‐edge populations could adapt to climate change. We highlight that prioritizing certain habitats for conservation (i.e., thermal refuges) could be crucial for this adaptation.

New York, Vermont, New Hampshire, Massachusetts↗
USGS2021

Consequences of migratory coupling of predators and prey when mediated by human actions

Aim Animal migrations influence ecosystem structure, dynamics and persistence of predator and prey populations. The theory of migratory coupling postulates that aggregations of migrant prey can induce large-scale synchronized movements in predators, and this coupling is consequential for the dynamics of ecological communities. The degree to which humans influence these interactions remains largely unknown. We tested whether creation of large resource pulses by humans such as seasonal herding of reindeer Rangifer tarandus and hunting of moose, Alces alces , can induce migratory coupling with Golden Eagles, Aquila chrysaetos, and whether these lead to demographic consequences for the eagles. Location Fennoscandia. Methods We used movement data from 32 tracked Golden Eagles spanning 125 annual migratory cycles over 8 years. We obtained reindeer distribution data through collaboration with reindeer herders based on satellite tracking of reindeer, and moose harvest data from the national hunting statistics for Sweden. We assessed demographic consequences for eagles from ingesting lead from ammunition fragments in moose carcasses through survival estimates and their links with lead concentrations in eagles' blood. Results In spring, eagles migrated hundreds of kilometres to be spatially and temporally coupled with calving reindeer, whereas in autumn, eagles matched their distribution with the location and timing of moose hunt. Juveniles were more likely to couple with reindeer calving, whereas adults were particularly drawn to areas of higher moose harvest. Due to this coupling, eagles ingested lead from spent ammunition in moose offal and carcasses and the resulting lead toxicity increased the risk of mortality by 3.4 times. Main conclusions We show how migratory coupling connects landscape processes and that human actions can influence migratory coupling over large spatial scales and increase demographic risks for predators. We provide vital knowledge towards resolving human–wildlife conflicts and the conservation of protected species over a large spatial and temporal scale.

Diversity and Distributions↗