Search

While the location of wildlife mortalities provides some insight on the cause of death, identifying the risk factors associated with mortality events and in which cases these factors result in death requires information on individual behaviour prior to death. With access to a long-term database of grizzly bear ( Ursus arctos L., 1758) GPS locations, we investigated how behaviour differed between individuals that died of anthropogenic causes and those that survived across different temporal scales. We analyzed movement (diurnality and daily displacement) and habitat use (modelled risk and habitat quality) of grizzly bears residing in Alberta, Canada, from 2005 to 2021 to determine whether grizzly bears that died and grizzly bears that survived differed in these behaviours 2–4 years, 1 year, and 1 week prior to death, and whether patterns changed over time. We found that diurnality increased in the last year of life, while displacement increased in the last week of life, with differences becoming greater nearer the day of death. Grizzly bears that died used high-risk and low-quality habitat at all time scales, and these behaviours increased as death approached. Our analysis suggests that grizzly bear mortalities do not occur randomly but happen at times when individuals exhibit high-risk behaviours. This information can be used to make management decisions related to habitat management, road use, and human access.

Context To mitigate conservation conflicts, some jurisdictions translocate large carnivores into novel environments where they have no previous experience. Behavioural responses of these individuals are not typically monitored to evaluate the impacts of this management approach on the animals or populations. Aims We examined how grizzly bears (Ursus arctos) involved in conservation conflict responded to novel environments after translocation. Methods We used GPS location data to compare grizzly bears translocated to a novel environment (n = 12) with bears resident within the new area (n = 12). Our analyses investigated differences between these groups in relation to exploration behaviour, habitat use and response to human-caused mortality risk. Key results Translocated bears had higher movement rates, greater daily displacement and revisited areas less frequently than did resident bears. They spent more time in poor-quality habitat and the habitat used was of even lower quality in the second year after translocation. Translocated bears selected for agricultural lands and active oil and gas wellsites. They also spent more time in areas with higher potential mortality risk than resident bears. However, translocated bears avoided residential areas, which resident bears selected, and crossed roads at the same rate as did resident bears. Both groups avoided campgrounds and recreation sites. Only 25% of bears engaged in further conflict behaviour after translocation and 67% of translocated bears survived over the 2-year monitoring period. Conclusions This work found differences in exploration behaviour and habitat use between translocated and resident bears, and showed that translocated bears can survive without reoffending during the critical few years following translocation. Implications Managers and the public should recognise potential impacts for translocating grizzly bears. Translocated bears require time to explore and learn within their new environment, a process that can occur without repeating conflict. When conflict behaviour does re-occur, it should be viewed as a part of animal learning and not immediately as failure. On the basis of the amount of time translocated bears spent near humans and anthropogenic features, our findings suggest that translocated bears do not pose a greater threat to humans than do resident bears.

Scent originates from excretions and secretions, and its chemical complexity in mammals translates into a diverse mode of signalling. Identifying how information is encoded can help to establish the mechanisms of olfactory communication and the use of odours as chemical signals. Building upon existing behavioural and histological literature, we examined the chemical profile of secretions used for scent marking by a solitary, non-territorial carnivore, the brown bear (Ursus arctos). We investigated the incidence, abundance, and uniqueness of volatile organic compounds (VOCs) from cutaneous glandular secretions of 12 wild brown bears collected during late and post-breeding season, and assessed whether age-sex class, body site, and individual identity explained profile variation. VOC profiles varied in the average number of compounds, compound incidence, and compound abundance by age-sex class and individual identity (when individuals were grouped by sex), but not by body site. Mature males differed from other age-sex classes, secreting fewer compounds on average with the least variance between individuals. Compound uniqueness varied by body site and age for both males and females and across individuals. Our results indicate that brown bear skin-borne secretions may facilitate age-sex class and individual recognition, which can contribute towards further understanding of mating systems and social behaviour.

Monitoring the reproductive characteristics of a species can complement existing conservation strategies by understanding the mechanisms underlying demography. However, methodology to determine important aspects of female reproductive biology is often absent in monitoring programs for large mammals. Protein biomarkers may be a useful tool to detect physiological changes that are indicative of reproductive state. This study aimed to identify protein biomarkers of reproductive status in serum collected from free-ranging female brown bears (Ursus arctos) in Alberta, Canada, from 2001 to 2018. We hypothesized that the expression of proteins related to reproduction in addition to energetics and stress can be used to answer specific management-focused questions: (i) identify when a female is pregnant, (ii) detect if a female is lactating, (iii) determine age of sexual maturity (i.e. primiparity) and (iv) assess female fertility (i.e. reproduction rate). Furthermore, we investigated if silver spoon effects (favourable early life conditions provide fitness benefits through adulthood) could be determined using protein expression. A target panel of 19 proteins with established relationships to physiological function was measured by peptide-based analysis using liquid chromatography and multiple reaction monitoring mass spectrometry and their differential expression was evaluated using a Wilcoxon signed-rank test. We found biomarkers of pregnancy (apolipoprotein B-100 and afamin), lactation (apolipoprotein B-100 and alpha-2-macroglobulin) and sexual maturity (corticosteroid-binding globulin), but there were no statistically significant relationships with protein expression and fertility. The expression of proteins related to reproduction (afamin) and energetics (vitamin-D binding protein) was associated with the nutritional quality of the individual’s present habitat rather than their early life habitat. This study highlights potential biomarkers of reproductive status and provides additional methods for monitoring physiological function in wildlife to inform conservation.

Chemicals present in urine are thought to play an important role in mate identification in the solitary giant panda (Ailuropoda melanoleuca). During the breeding season, females will deposit chemical signals to advertise sexual receptivity to potential mates. The goal of this study was to determine if specific volatile compounds found in female urine could be considered as pheromones that elicit behavioral and physiological responses in males. Experimental simultaneous choice trials were conducted with captive male giant pandas (n = 3) housed at Memphis Zoo, San Diego Zoo, and Zoo Atlanta. Octanoic acid, 1H-pyrrole-2-carboxaldehyde, decanoic acid, and civetone were selected as stimuli because previous studies reported their elevation in urine during the breeding season. Male interest was determined by a behavioral preference toward these volatile compounds diluted in synthetic urine compared with nontreated synthetic urine. Male urine samples were collected 1 week prior, during, and 1 week after the experimental period to assess changes in urinary semiochemical composition and urinary androgen concentrations. No significant differences in investigation response (p = .395) or flehmen response (p = .600) were found when stimuli were compared; however, decanoic acid and civetone elicited a behavioral preference over the control (response ratio > 0.5). The relative abundance of 16 compounds identified in male urine was significantly elevated (p < .05) above baseline values after the males were exposed to the stimuli. Androgen levels were significantly elevated (p < .05) in one male after exposure to 1H-pyrrole-2-carboxaldehyde, decanoic acid, and civetone. These data suggested that civetone and decanoic acid in female urine may motivate sexual responses in males.

Environmental change has been shown to influence mammalian distribution, habitat use, and behavior; however, few studies have investigated the impact on physiological function. This study aimed to determine the influence of landscape condition on the expression of target proteins related to energetics, reproduction, and stress in grizzly bears. We hypothesized that changes in landscape condition explains protein expression. Skin biopsies were collected from free-ranging grizzly bears in Alberta, Canada from 2013–2019 (n = 86 individuals). We used an information theoretic approach to develop 11 a priori candidate generalized linear mixed models to explain protein expression. We compared models using Akaike Information Criteria (AICc) weights and averaged models with ΔAICc

Enzyme immunoassays (EIAs) are a common tool for measuring steroid hormones in wildlife due to their low cost, commercial availability, and rapid results. Testing technologies improve continuously, sometimes requiring changes in protocols or crucial assay components. Antibody replacement between EIA kits can cause differences in EIA sensitivity, which can hinder monitoring hormone concentration over time. The antibody in a common cortisol EIA kit used for long-term monitoring of stress in wildlife was replaced in 2014, causing differences in cross reactivity and standard curve concentrations. Therefore, the objective of this study was to develop a method to standardize results following changes in EIA sensitivity. We validated this method using cortisol concentrations measured in the hair of brown bears (Ursus arctos).•We used a simple linear regression to model the relationship between cortisol concentrations using kit 1 and kit 2.•We found a linear relationship between the two kits (R2 = 0.85) and used the regression equation (kit2 = (0.98 × kit1) + 1.65) to predict cortisol concentrations in re-measured samples.•Mean predicted percent error was 16% and 72% of samples had a predicted percent error, Graphical abstract Image, graphical abstract

Grizzly bears (Ursus arctos) in west‐central Alberta occupy an increasingly human‐dominated landscape. Natural resource extraction activities are hypothesized to increase stress in animals that reside in such changing landscapes by influencing habitat and resource availability. Our study aimed to determine whether stress, represented by hair cortisol concentration (HCC), was associated with variables related to landscape conditions in a population that increased by 7% annually from 2004 to 2014. Hair samples (n = 157) were collected using barbwire hair snags placed throughout the Yellowhead bear management area in Alberta, Canada. Candidate models were developed a priori representing hypotheses related to biologically and ecologically plausible relationships between HCC and landscape variables. Generalized linear model analysis with landscape attributes representing anthropogenic disturbance, food resource availability, and terrain conditions was used to determine potential drivers of HCC. We found support (ΔAICc ≤ 2.00) for three models that included variables from each hypothesis. Anthropogenic variables had the greatest impact on HCC; increasing oil and gas well‐site density resulted in reduced HCC, while increasing distance to coal mines resulted in elevated HCC. Hair cortisol concentration also increased as forest crown closure became more variable, while HCC decreased as the soil wetness (represented by compound topographic index) increased. Some forms of anthropogenic disturbance have been linked to increased food availability for this species. Therefore, we suggest that changes in landscape conditions from 2004 to 2014 may have indirectly increased food abundance and ultimately resulted in a reduction in HCC at a population level during this time period. Measuring HCC provides a non‐invasive and important monitoring strategy to assess the impact of environmental change on residing species and should be considered in landscape management decisions.

Male giant pandas identify female sexual receptivity through the detection of olfactory cues in estrous urine. However, it is yet unknown which specific days of the female estrous cycle may provoke male sexual-social responses and a physiological readiness to mate. We hypothesized that female urine from specific days of the estrous cycle will be positively associated with specific changes in male behaviors, urinary semiochemical production, and steroidogenic activity. Experimental simultaneous choice trials were conducted in captivity with four male giant pandas during the spring breeding season and during fall. Male interest was determined by a behavioral preference toward peri-estrual urine collected from a specific day of the estrous cycle encompassing proestrus (Day -13, Day -6, Day -3, Day -2), estrus (Day -1 and Day 0), and metestrus (Day four and Day nine) over that of anestrous urine. Provocation of male sexual motivation was examined by changes in urinary semiochemical composition and urinary androgen concentrations. During the spring, male investigative behaviors indicated a preference for Day -13, Day -3 and Day 0 urine over anestrous urine, while no significant preferences for estrous urine could be detected during fall. The relative abundance of only three compounds in male urine were significantly higher above baseline values after males were exposed to peri-estrual urine during spring; whereas 34 compounds significantly increased in the fall. Similarly, androgen concentrations increased above baseline in only two out of four males during spring, while all males had elevated androgen concentrations after exposure to Day -3 urine during the fall. Our results suggest that peri-estrual urine from Day -13, Day -3, and Day 0 elicited the greatest duration of male investigation, changes in the semiochemical profile, and elevations in androgen levels. These data suggest that managers should incorporate a combination of behavioral, semiochemical, and endocrinological assessment of males in the reproductive management of giant pandas to determine impending ovulation and pinpoint the best time for male-female introductions and artificial inseminations.

Large carnivores play critical roles in the maintenance and function of natural ecosystems; however, the populations of many of these species are in decline across the globe. Therefore, there is an urgent need to develop novel techniques that can be used as sensitive conservation tools to detect new threats to the health of individual animals well in advance of population-level effects. Our study aimed to determine the expression of proteins related to energetics, reproduction and stress in the skin of grizzly bears (Ursus arctos) using a liquid chromatography and multiple reaction monitoring mass spectrometry assay. We hypothesized that a suite of target proteins could be measured using this technique and that the expression of these proteins would be associated with biological (sex, age, sample location on body) and environmental (geographic area, season, sample year) variables. Small skin biopsies were collected from free-ranging grizzly bears in Alberta, Canada, from 2013 to 2019 (n = 136 samples from 111 individuals). Over 700 proteins were detected in the skin of grizzly bears, 19 of which were chosen as targets because of their established roles in physiological function. Generalized linear mixed model analysis was used for each target protein. Results indicate that sample year influenced the majority of proteins, suggesting that physiological changes may be driven in part by responses to changes in the environment. Season influenced the expression of proteins related to energetics, reproduction and stress, all of which were lower during fall compared to early spring. The expression of proteins related to energetics and stress varied by geographic area, while the majority of proteins that were affected by biological attributes (age class, sex and age class by sex interaction) were related to reproduction and stress. This study provides a novel method by which scientists and managers can further assess and monitor physiological function in wildlife.

Natural and anthropogenic stressors have been reported to impact the health of marine mammals. Therefore, investigation of quantifiable biomarkers in response to stressors is required. We hypothesized that stress protein expression would be associated with biological and health variables in wild and managed-care bottlenose dolphins (Tursiops truncatus). To test this hypothesis, our study objectives were to (1) determine if stress proteins in skin, white blood cells (WBCs), and plasma could be measured with an antibody-based microarray, (2) measure stress-protein expression relative to biological data (location, sex, age, environment), and (3) determine if stress-protein expression was associated with endocrine, hematological, biochemical and serological variables and gene expression in bottlenose dolphins. Samples were collected from two wild groups (n = 28) and two managed-care groups (n = 17). Proteins involved in the HPA axis, apoptosis, proteotoxicity, and inflammation were identified as stress proteins. The expression of 3 out of 33 proteins was significantly (P 0.05) greater in skin than plasma and WBCs. Male dolphins had significantly greater expression levels for 10 proteins in skin compared to females. The greatest number of stress-associated proteins varied by the dolphins' environment; nine were greater in managed-care dolphins and 15 were greater in wild dolphins, which may be related to wild dolphin disease status. Protein expression in skin and WBCs showed many positive relationships with measures of plasma endocrinology and biochemistry. This study provides further understanding of the underlying mechanisms of the stress response in bottlenose dolphins and application of a combination of novel methods to measure stress in wildlife.

Giant pandas (Ailuropoda melanoleuca) use chemical cues to determine identity, gender, and sexual receptivity of conspecifics. We hypothesized that volatile chemical profiles of free-ranging giant pandas are detectable in air. Therefore, we aimed to identify volatile compounds produced by free-ranging giant pandas residing in the Wolong Nature Reserve (Sichuan, China) through field air analysis/solid phase microextraction/gas chromatography–mass spectrometry (FAA/SPME/GCMS). From 28 June to 12 July 2017, 3 SPME fibers were secured to trees that appeared to have previous marking activity. Trail cameras confirmed that a single giant panda performed scent-marking behavior at one sampling location. The abundance of 7 compounds were elevated in samples collected from the tree visited by the giant panda compared with controls. Three of these compounds (Ethane, 1,1-dinitro-; Octane, 4-ethyl-; 2(1H)-Pyridinethione, 3-ethoxy-6-methyl-) were unique to the giant panda visit. Novel methods to detect giant pandas would benefit conservation efforts. We suggest our method also may be used to study chemical communication in other bear species.

Chemical cues are thought to play an important role in mate identification in the solitary giant panda (Ailuropoda melanoleuca). The goal of this study was to detect and identify volatile compounds present in the enclosure air of captive giant pandas. We hypothesized that a subset of compounds produced from breeding animals would be detected in environmental samples because highly volatile chemicals are likely to facilitate mate detection. Samples were collected from the enclosures of 8 giant pandas (n = 4 male, n = 4 female) during the Mar-June breeding season and the Aug-Jan non-breeding period from 2012–2015. Volatile compounds were captured by securing a solid phase micro extraction fiber approximately 3 meters above the ground within a panda enclosure for 6–12 hours. Compounds adsorbed onto the SPME fibers were analyzed by gas chromatography mass spectrometry. Thirty-three compounds were detected in at least 10% of all samples within individual and season and across all subjects within each season. Aromatic compounds made up 27.3% of the enclosure volatile profile, while 21.2% was made of cyclic aliphatic compounds and 51.5% of the enclosure profile was comprised of acyclic aliphatic compounds. Three compounds were likely to be present in male enclosures regardless of season, while Undecane, 4-methyl had a significant (p