Geology topics

Daniel R. Stahler

Publications and source records attributed to Daniel R. Stahler.

At least 19 recordsLinked to original sources

USGS2026

Interacting effects of human presence and landscape modification on birds and mammals

Sustainable human–wildlife coexistence requires a mechanistic understanding of the many ways that humans affect animals. However, progress is hampered by the lack of accessible data measuring the dynamic presence of people. Here, we leverage mobile-device data to disentangle how human presence and landscape modification differentially influence the use of geographic and environmental space for 37 mammal and bird species across the United States. Human presence affected more than 65% of species, with substantial variation across species. For ~60% of species that responded to human activities, the effects were interdependent—animals tended to react more strongly to human presence in less modified habitats. Our results demonstrate that human presence and landscape modification have complex combined effects on wildlife, which need to be considered for effective management.

Science↗

USGS2025

Expression and mechanisms of behavioral plasticity in large mammals

Behavioral plasticity, the alteration of behavior in response to stimuli, is becoming increasingly important in the context of human-induced rapid environmental change. Theoretical and empirical studies suggest that the expression and magnitude of behavioral plasticity are likely facilitated or constrained primarily by two factors: environmental variation and endogenous traits such as body size. The contextual role of these factors on behavioral plasticity, however, is poorly understood; there are relatively few studies that have compared the magnitude and potential drivers of behavioral plasticity at different levels (i.e., population and individual) across species, especially in free-ranging animals with diverse behavioral traits such as large mammals. Here, we quantify and test potential hypotheses for the mechanisms underpinning behavioral plasticity at the individual and population level in response to variation in summer temperatures for 1068 animal-years in 17 populations across nine species of large mammals. All populations displayed behavioral plasticity in response to increased temperatures, modifying their relative selection for heat-relieving habitat attributes (e.g., elevation) and heat-generating behavior (i.e., movement speed). We found strong support for the hypothesis that the variability of the physical environment is an important driver of behavioral plasticity—both mean population behavioral plasticity and variation among individuals within each population in plasticity were lower with increased heterogeneity of habitat attributes such as tree cover. Yet, the variability in environmental conditions (i.e., the magnitude of the temperature increase) had no effect on behavioral plasticity within and among populations. We did not detect an effect of endogenous traits on the expression of behavioral plasticity; however, we note that data availability limited our tests of this hypothesis to a select few endogenous traits (body size, feeding guild, and sex of the tracked individuals) that predominantly vary at the species level, for which we had one to three replicate populations per species. Our results provide an integrative and generalizable understanding of the expression of behavioral plasticity among populations of large mammals in temperate environments and emphasize the important but nuanced role of environmental variation in determining the scope of behavioral plasticity in these populations.

Wyoming↗

USGS2023

Forage senescence and disease influence elk pregnancy across the Greater Yellowstone Ecosystem

For various temperate ungulate species, recent research has highlighted the potential for spring vegetation phenology (“green-up”) to influence individual condition, with purported benefits to population productivity. However, few studies have been able to measure the benefit on vital rates directly, and fewer still have investigated the comparative influence of other phenological periods on ungulate vital rates. In this study, we tracked phenological changes throughout the duration of the growing season and examined how their timing affected the probability of pregnancy in an ungulate population. We did this for elk ( Cervus canadensis ) across the Greater Yellowstone Ecosystem (GYE) by sampling 1106 adult females in winter at 25 sites over a 13-year period and assessing sources of variation in pregnancy using a Bayesian hierarchical model. Pregnancy rates were generally high across the GYE (82.4%), and the primary influences on probability of pregnancy were the timing of vegetation senescence (“brown-down”) in autumn and exposure to the reproductive disease brucellosis. Earlier forage brown-down in fall negatively influenced the probability of pregnancy of elk aged 6–9 years by an estimated 17.2% within the range (ca. 32 days) of observed brown-down end dates. While summer habitat quality has been inferred to influence elk pregnancy previously, our findings specify the key influence of foraging conditions later in the seasonal cycle, immediately before the breeding season. The reproductive disease brucellosis was also an important factor, reducing the probability of pregnancy by 12.4% in elk in the 6- to 9-year age class. Because pregnancy was tested before most disease-induced abortions occur, the apparent mechanism for this effect is a prolonged reduction in fertility beyond the period of initial exposure in which fetal mortality is typically expected. Our results prompt greater scrutiny of the combined effects of late-season phenology and disease on reproductive rates and population productivity in temperate ungulates.

Idaho, Montana, Wyoming↗

USGS2023

Diverse migratory portfolios drive inter-annual switching behavior of elk across the Greater Yellowstone Ecosystem

A growing body of evidence shows that some ungulates alternate between migratory and nonmigratory behaviors over time. Yet it remains unclear whether such short-term behavioral changes can help explain reported declines in ungulate migration worldwide, as opposed to long-term demographic changes. Furthermore, advances in tracking technology reveal that a simple distinction between migration and nonmigration may not sufficiently describe all individual behaviors. To better understand the dynamics and drivers of ungulate switching behavior, we investigated 14 years of movement data from 361 elk in 20 herds across the Greater Yellowstone Ecosystem (GYE). First, we categorized yearly individual behaviors using a clustering algorithm that identified similar migratory tactics across a continuum of behaviors. Then, we tested seven hypotheses to explain why some ungulates switch behaviors, and we evaluated how behavioral changes affected the proportions of different behaviors across the system. We identified four distinct behavioral tactics: residents (4.8% of elk-years), short-distance migrants (53.7%), elevational migrants (21.9%) and long-distance migrants (19.6%). Of the 20 herds, 18 were partially migratory, and 5 had all four movement tactics present. We observed switches between migratory tactics in all sets of consecutive years during our study period, with an average of 22.5% of individual elk changing movement tactics from one year to the next. Elk in herds with higher movement tactic diversity were significantly more likely to switch tactics and often responded more effectively to adverse environmental conditions, compared to those in herds with low movement tactic diversity. During our study period, switching increased the prevalence of both short- and long-distance migrants, decreased the prevalence of elevational migrants, and had no effect on the prevalence of residents. Our findings suggest that rather than contributing to the declining migratory behavior found in the GYE, switching behavior may enable greater resiliency to continuously changing environmental and anthropogenic conditions.

Wyoming↗

USGS2022

Automatic recorders monitor wolves at rendezvous sites: do wolves adjust howling to live near humans?

We used automatic sound recorders to study spontaneous vocalizations of wild wolves during the pup-rearing season around rendezvous sites from 24 wolf packs in six study areas across North America, Asia, and Europe. Between 2018 and 2021, for a total of 1225 pack-days, we recorded 605 spontaneous wolf chorus howls and 224 solo-howl series. Howling occurrence varied across areas, from 12.50 to 94.12% days with howling. Daily howling ranged from 0.00 to 3.47 solo howls/day and 0.13 to 5.29 chorus howls/day. Generally, spontaneous chorus howls peaked between sunset and sunrise. Howling rate depended on area, pack size, and density of people living nearby, being greater where fewer people lived. High rates in Yellowstone National Park, (800,000+ visitors during the study) could reflect accommodation to human activities such as wolf watching. One to six automatic recorders per site within 1000 m of rendezvous sites needed 4–15 days to detect the pack (average 9.5) and 5–21 days (average 11.3) to detect pups, both with a probability of 95%. Our results may guide wolf-monitoring programs using automatic sound recorders, a promising method offering advantages over howling surveys, especially in human-dominated landscapes.

Biodiversity and Conservation↗

USGS2022

Evaluating noninvasive methods for estimating cestode prevalence in a wild carnivore population

Helminth infections are cryptic and can be difficult to study in wildlife species. Helminth research in wildlife hosts has historically required invasive animal handling and necropsy, while results from noninvasive parasite research, like scat analysis, may not be possible at the helminth species or individual host levels. To increase the utility of noninvasive sampling, individual hosts can be identified by applying molecular methods. This allows for longitudinal sampling of known hosts and can be paired with individual-level covariates. Here we evaluate a combination of methods and existing long-term monitoring data to identify patterns of cestode infections in gray wolves in Yellowstone National Park. Our goals were: (1) Identify the species and apparent prevalence of cestodes infecting Yellowstone wolves; (2) Assess the relationships between wolf biological and social characteristics and cestode infections; (3) Examine how wolf samples were affected by environmental conditions with respect to the success of individual genotyping. We collected over 200 wolf scats from 2018–2020 and conducted laboratory analyses including individual wolf genotyping, sex identification, cestode identification, and fecal glucocorticoid measurements. Wolf genotyping success rate was 45%, which was higher in the winter but decreased with higher precipitation and as more time elapsed between scat deposit and collection. One cestode species was detected in 28% of all fecal samples, and 38% of known individuals. The most common infection was Echinococcus granulosus sensu lato (primarily E . canadensis ). Adult wolves had 4x greater odds of having a cestode infection than pups, as well as wolves sampled in the winter. Our methods provide an alternative approach to estimate cestode prevalence and to linking parasites to known individuals in a wild host system, but may be most useful when employed in existing study systems and when field collections are designed to minimize the time between fecal deposition and collection.

PLoS ONE↗

USGS2022

Examination of the interaction between age-specific predation and chronic disease in the Greater Yellowstone Ecosystem

Predators may create healthier prey populations by selectively removing diseased individuals. Predators typically prefer some ages of prey over others, which may, or may not, align with those prey ages that are most likely to be diseased. The interaction of age-specific infection and predation has not been previously explored and likely has sizable effects on disease dynamics. We hypothesize that predator cleansing effects will be greater when the disease and predation occur in the same prey age groups. We examine the predator cleansing effect using a model where both vulnerability to predators and pathogen prevalence vary with age. We tailor this model to chronic wasting disease (CWD) in mule deer and elk populations in the Greater Yellowstone Ecosystem, with empirical data from Yellowstone grey wolves and cougars. Model results suggest that under moderate, yet realistic, predation pressure from cougars and wolves independently, predators may decrease CWD outbreak size substantially and delay the accumulation of symptomatic deer and elk. The magnitude of this effect is driven by the ability of predators to selectively remove late-stage CWD infections that are likely the most responsible for transmission, but this may not be the age class they typically select. Thus, predators that select for infected young adults over uninfected juveniles have a stronger cleansing effect, and these effects are strengthened when transmission rates increase with increasing prey morbidity. There are also trade-offs from a management perspective—that is, increasing predator kill rates can result in opposing forces on prey abundance and CWD prevalence. Our modelling exploration shows that predators have the potential to reduce prevalence in prey populations when prey age and disease severity are considered, yet the strength of this effect is influenced by predators' selection for demography or body condition. Current CWD management focuses on increasing cervid hunting as the primary management tool, and our results suggest predators may also be a useful tool under certain conditions, but not necessarily without additional impacts on host abundance and demography. Protected areas with predator populations will play a large role in informing the debate over predator impacts on disease.

Wyoming↗

USGS2022

Wildlife migrations highlight importance of both private lands and protected areas in the Greater Yellowstone Ecosystem

Formally protected areas are an important component of wildlife conservation, but face limitations in their effectiveness for migratory species. Improved stewardship of working lands around protected areas is one solution for conservation planning, but private working lands are vulnerable to development. In the Greater Yellowstone Ecosystem (GYE), ungulates such as elk ( Cervus canadensis ) use both protected areas and private lands throughout their annual migrations. We studied patterns of landownership, protection, and conservation challenges within the ranges of migratory elk in the GYE. We used GPS data from 1088 elk in 26 herds to define herd-level seasonal ranges, and extracted covariates related to landownership and protection, land use, and human infrastructure and development. All elk herds used land encompassing >1 ownership type. Most elk herds (92.3 % of herds, n = 24) used the highest proportion of private land in the winter (mean = 36.2 % private land). Most elk herds' winter ranges contained the highest building densities (mean = 1.24 buildings/km 2 ), fence densities (mean = 1.02 km fence/km 2 ), and cattle grazing (mean = 1.9 cows/km 2 ), compared to migratory and summer ranges. Out of all ranges, 36.5 % of ranges did not have any zoning regulations, indicating the potential for future development. Our results show that elk in the GYE rely on habitat outside of protected areas, and face landscape-scale conservation challenges such as habitat fragmentation from human development, particularly in winter ranges. Future conservation strategies for wildlife in this system need to encompass coordination across both public and private land to ensure migratory connectivity.

Idaho, Montana, Wyoming↗

USGS2022

Disease outbreaks select for mate choice and coat color in wolves

We know much about pathogen evolution and the emergence of new disease strains, but less about host resistance and how it is signaled to other individuals and subsequently maintained. The cline in frequency of black-coated wolves ( Canis lupus ) across North America is hypothesized to result from a relationship with canine distemper virus (CDV) outbreaks. We tested this hypothesis using cross-sectional data from wolf populations across North America that vary in the prevalence of CDV and the allele that makes coats black, longitudinal data from Yellowstone National Park, and modeling. We found that the frequency of CDV outbreaks generates fluctuating selection that results in heterozygote advantage that in turn affects the frequency of the black allele, optimal mating behavior, and black wolf cline across the continent.

Science↗

USGS2021

Patterns and processes of pathogen exposure in gray wolves across North America

The presence of many pathogens varies in a predictable manner with latitude, with infections decreasing from the equator towards the poles. We investigated the geographic trends of pathogens infecting a widely distributed carnivore: the gray wolf ( Canis lupus ). Specifically, we investigated which variables best explain and predict geographic trends in seroprevalence across North American wolf populations and the implications of the underlying mechanisms. We compiled a large serological dataset of nearly 2000 wolves from 17 study areas, spanning 80° longitude and 50° latitude. Generalized linear mixed models were constructed to predict the probability of seropositivity of four important pathogens: canine adenovirus, herpesvirus, parvovirus, and distemper virus—and two parasites: Neospora caninum and Toxoplasma gondii . Canine adenovirus and herpesvirus were the most widely distributed pathogens, whereas N. caninum was relatively uncommon. Canine parvovirus and distemper had high annual variation, with western populations experiencing more frequent outbreaks than eastern populations. Seroprevalence of all infections increased as wolves aged, and denser wolf populations had a greater risk of exposure. Probability of exposure was positively correlated with human density, suggesting that dogs and synanthropic animals may be important pathogen reservoirs. Pathogen exposure did not appear to follow a latitudinal gradient, with the exception of N. caninum . Instead, clustered study areas were more similar: wolves from the Great Lakes region had lower odds of exposure to the viruses, but higher odds of exposure to N. caninum and T. gondii ; the opposite was true for wolves from the central Rocky Mountains. Overall, mechanistic predictors were more informative of seroprevalence trends than latitude and longitude. Individual host characteristics as well as inherent features of ecosystems determined pathogen exposure risk on a large scale. This work emphasizes the importance of biogeographic wildlife surveillance, and we expound upon avenues of future research of cross-species transmission, spillover, and spatial variation in pathogen infection.

Alaska, Alberta, Arizona, British Columbia, Michig↗

USGS2021

Group density, disease, and season shape territory size and overlap of social carnivores

1. The spatial organization of a population can influence the spread of information, behaviour, and pathogens. Territory size and territory overlap, components of spatial organization, provide key information as these metrics may be indicators of habitat quality, resource dispersion, contact rates, and environmental risk (e.g., indirectly transmitted pathogens). Furthermore, sociality and behaviour can also shape space use, and subsequently, how space use and habitat quality together impact demography. 2. Our study aims to identify factors shaping the spatial organization of wildlife populations and assess the impact of epizootics on space use. We also use network analysis to describe spatial organization and connectivity of social groups. 3. Here, we assessed the seasonal spatial organization of Serengeti lions and Yellowstone wolves at the group level. We examine the factors predicting mean territory size and mean territory overlap for each population using generalized additive models. We further explore the mechanisms by which disease perturbations could cause changes in spatial organization. 4. We demonstrate that lions and wolves were similar in that group-level factors, such as number of groups, shaped spatial organization more than population-level factors, such as population density. Factors shaping territory size were slightly different than factors shaping territory overlap; for example, wolf pack size was an important predictor of territory overlap, but not territory size. Lion spatial networks were more highly connected, while wolf spatial networks varied seasonally. We found that resource dispersion may be more important for driving territory size and overlap for wolves than for lions. Additionally, canine distemper epizootics may alter lion spatial organization, highlighting the importance of including behavioural and movement ecology in studies of pathogen transmission dynamics. 5. We provide insight about when we might expect to observe the impacts of resource dispersion, disease perturbations, and other ecological factors on spatial organization. Our work highlights the importance of monitoring and managing social carnivore populations at the group level. Future research should elucidate the complex relationships between demographics, social and spatial structure, abiotic and biotic conditions, and pathogen infections.

Journal of Animal Ecology↗

USGS2018

Estimating distemper virus dynamics among wolves and grizzly bears using serology and Bayesian state‐space models

Many parasites infect multiple hosts, but estimating the transmission across host species remains a key challenge in disease ecology. We investigated the within and across host species dynamics of canine distemper virus (CDV) in grizzly bears ( Ursus arctos ) and wolves ( Canis lupus ) of the Greater Yellowstone Ecosystem (GYE). We hypothesized that grizzly bears may be more likely to be exposed to CDV during outbreaks in the wolf population because grizzly bears often displace wolves while scavenging carcasses. We used serological data collected from 1984 to 2014 in conjunction with Bayesian state‐space models to infer the temporal dynamics of CDV. These models accounted for the unknown timing of pathogen exposure, and we assessed how different testing thresholds and the potential for testing errors affected our conclusions. We identified three main CDV outbreaks (1999, 2005, and 2008) in wolves, which were more obvious when we used higher diagnostic thresholds to qualify as seropositive. There was some evidence for increased exposure rates in grizzly bears in 2005, but the magnitude of the wolf effect on bear exposures was poorly estimated and depended upon our prior distributions. Grizzly bears were exposed to CDV prior to wolf reintroduction and during time periods outside of known wolf outbreaks, thus wolves are only one of several potential routes for grizzly bear exposures. Our modeling approach accounts for several of the shortcomings of serological data and is applicable to many wildlife disease systems, but is most informative when testing intervals are short. CDV circulates in a wide range of carnivore species, but it remains unclear whether the disease persists locally within the GYE carnivore community or is periodically reintroduced from distant regions with larger host populations.

Ecology and Evolution↗

USGS2018

Diel predator activity drives a dynamic landscape of fear

A “landscape of fear” (LOF) is a map that describes continuous spatial variation in an animal's perception of predation risk. The relief on this map reflects, for example, places that an animal avoids to minimize risk. Although the LOF concept is a potentially unifying theme in ecology that is often invoked to explain the ecological and conservation significance of fear, little is known about the daily dynamics of an LOF. Despite theory and data to the contrary, investigators often assume, implicitly or explicitly, that an LOF is a static consequence of a predator's mere presence within an ecosystem. We tested the prediction that an LOF in a large‐scale, free‐living system is a highly dynamic map with “peaks” and “valleys” that alternate across the diel (24‐h) cycle in response to daily lulls in predator activity. We did so with extensive data from the case study of Yellowstone elk ( Cervus elaphus ) and wolves ( Canis lupus ) that was the original basis for the LOF concept. We quantified the elk LOF, defined here as spatial allocation of time away from risky places and times, across nearly 1,000‐km 2 of northern Yellowstone National Park and found that it fluctuated with the crepuscular activity pattern of wolves, enabling elk to use risky places during wolf downtimes. This may help explain evidence that wolf predation risk has no effect on elk stress levels, body condition, pregnancy, or herbivory. The ability of free‐living animals to adaptively allocate habitat use across periods of high and low predator activity within the diel cycle is an underappreciated aspect of animal behavior that helps explain why strong antipredator responses may trigger weak ecological effects, and why an LOF may have less conceptual and practical importance than direct killing.

Yellowstone National Park↗

USGS2018

Factors affecting gray wolf (Canis lupus) encounter rate with elk (Cervus elaphus) in Yellowstone National Park

Despite encounter rates being a key component of kill rate, few studies of large carnivore predation have quantified encounter rates with prey, the factors that influence them, and the relationship between encounter rate and kill rate. The study’s primary motivation was to determine the relationship between prey density and encounter rate in understanding the mechanism behind the functional response. Elk (Cervus elaphus Linnaeus, 1758) population decline and variable weather in northern Yellowstone National Park provided an opportunity to examine how these factors influenced wolf (Canis lupus Linnaeus, 1758) encounter rates with elk. We explored how factors associated with wolf kill rate and encounter rate in other systems (season, elk density, elk group density, average elk group size, snow depth, wolf pack size, and territory size) influenced wolf–elk encounter rate in Yellowstone National Park. Elk density was the only factor significantly correlated with wolf–elk encounter rate, and we found a nonlinear density-dependent relationship that may be a mechanism for a functional response in this system. Encounter rate was correlated with number of elk killed during early winter but not late winter. Weak effects of snow depth and elk group size on encounter rate suggest that these factors influence kill rate via hunting success because kill rate is the product of hunting success and encounter rate.

Wyoming↗

USGS2017

Sexually dimorphic aggression indicates male gray wolves specialize in pack defense against conspecific groups

Aggression directed at conspecific groups is common among gregarious, territorial species, and for some species such as gray wolves ( Canis lupus ) intraspecific strife is the leading cause of natural mortality. Each individual in a group likely has different measures of the costs and benefits associated with a group task, such as an aggressive attack on another group, which can alter motivation and behavior. We observed 292 inter-pack aggressive interactions in Yellowstone National Park between 1 April 1995 and 1 April 2011 (>5300 days of observation) in order to determine the role of both sexes, and the influence of pack, age, and other traits on aggression. We recorded the behaviors and characteristics of all individuals present during the interactions (n = 534 individuals) and which individuals participated in each step (i.e. chase, attack, kill, flight) of the interaction. Overall, all wolves were more likely to chase rivals if they outnumbered their opponent, suggesting packs accurately assess their opponent’s size during encounters and individuals adjust their behavior based on relative pack size. Males were more likely than females to chase rival packs and gray-colored wolves were more aggressive than black-colored wolves. Male wolves and gray-colored wolves also recorded higher cortisol levels than females and black-colored wolves, indicating hormonal support for more intense aggressive behavior. Further, we found a positive correlation between male age and probability of chasing, while age-specific participation for females remained constant. Chasing behavior was influenced by the sex of lone intruders, with males more likely to chase male intruders. This difference in behavior suggests male and female wolves may have different strategies and motivations during inter-pack aggressive interactions related to gray wolf mating systems. A division of labor between pack members concerning resource and territory defense suggests selection for specific traits related to aggression is an adaptive response to intense competition between groups of conspecifics.

Behavioural Processes↗

USGS2016

Dog days of summer: Influences on decision of wolves to move pups

For animals that forage widely, protecting young from predation can span relatively long time periods due to the inability of young to travel with and be protected by their parents. Moving relatively immobile young to improve access to important resources, limit detection of concentrated scent by predators, and decrease infestations by ectoparasites can be advantageous. Moving young, however, can also expose them to increased mortality risks (e.g., accidents, getting lost, predation). For group-living animals that live in variable environments and care for young over extended time periods, the influence of biotic factors (e.g., group size, predation risk) and abiotic factors (e.g., temperature and precipitation) on the decision to move young is unknown. We used data from 25 satellite-collared wolves ( Canis lupus ) in Idaho, Montana, and Yellowstone National Park to evaluate how these factors could influence the decision to move pups during the pup-rearing season. We hypothesized that litter size, the number of adults in a group, and perceived predation risk would positively affect the number of times gray wolves moved pups. We further hypothesized that wolves would move their pups more often when it was hot and dry to ensure sufficient access to water. Contrary to our hypothesis, monthly temperature above the 30-year average was negatively related to the number of times wolves moved their pups. Monthly precipitation above the 30-year average, however, was positively related to the amount of time wolves spent at pup-rearing sites after leaving the natal den. We found little relationship between risk of predation (by grizzly bears, humans, or conspecifics) or group and litter sizes and number of times wolves moved their pups. Our findings suggest that abiotic factors most strongly influence the decision of wolves to move pups, although responses to unpredictable biotic events (e.g., a predator encountering pups) cannot be ruled out.

Journal of Mammalogy↗

USGS2016

Energetic costs of mange in wolves estimated from infrared thermography

Parasites, by definition, extract energy from their hosts and thus affect trophic and food web dynamics even when the parasite may have limited effects on host population size. We studied the energetic costs of mange ( Sarcoptes scabiei ) in wolves ( Canis lupus ) using thermal cameras to estimate heat losses associated with compromised insulation during the winter. We combined the field data of known, naturally infected wolves with data set on captive wolves with shaved patches of fur as a positive control to simulate mange-induced hair loss. We predict that during the winter in Montana, more severe mange infection increases heat loss by around 5.2 to 12 MJ per night (1240 to 2850 kcal, or a 65% to 78% increase) for small and large wolves, respectively accounting for wind effects. To maintain body temperature would require a significant proportion of a healthy wolf's total daily energy demands (18-22 MJ/day). We also predict how these thermal costs may increase in colder climates by comparing our predictions in Bozeman, Montana to those from a place with lower ambient temperatures (Fairbanks, Alaska). Contrary to our expectations, the 14°C differential between these regions was not as important as the potential differences in wind speed. These large increases in energetic demands can be mitigated by either increasing consumption rates or decreasing other energy demands. Data from GPS-collared wolves indicated that healthy wolves move, on average, 17 km per day, which was reduced by 1.5, 1.8 and 6.5 km for light, medium, and severe hair loss. In addition, the wolf with the most hair loss was less active at night and more active during the day, which is the converse of the movement patterns of healthy wolves. At the individual level mange infections create significant energy demands and altered behavioral patterns, this may have cascading effects on prey consumption rates, food web dynamics, predator-prey interactions, and scavenger communities.

Montana↗

USGS2016

Territoriality and inter-pack aggression in gray wolves: shaping a social carnivore's life history

When Rudyard Kipling wrote The Jungle Book in 1894 and included the famous line "For the strength of the Wolf is the Pack, and the strength of the Pack is the Wolf," he would have had no idea that over a century later, scientific research would back up his poetic phrase. Recent studies in Yellowstone have found that both the individual wolf and the collective pack rely on each other and play important roles in territoriality. At a time when most fairy tales and fables were portraying wolves as demonic killers or, at best, slapstick gluttons, Kipling seemed to have a respect or even reverence for the wolf. Wolves in The Jungle Book raise and mentor the main character Mowgli, with the pack's leader eventually dying to save the "man-cub" from a pack of wolves. Kipling may have extended intra- pack benevolence to a human boy for literary sake, but he was clearly enthralled with how pack members treat each other. As wolf packs are almost always family units, most commonly comprised of a breeding pair and their offspring from several years, amiable behavior within the pack is unsurprising. By contrast, wolf packs are fiercely intolerant of their neighbors, their rivals. And this competition is proving to be an important facet in the life of a wolf and its pack.

Yellowstone Science↗