Evaluating behavioral syndromes in coyotes (Canis latrans)

Stress in the city? Coyote hair cortisol varies with intrinsic and extrinsic factors within a heavily urbanized landscape

Wildlife living in proximity to people are exposed to both natural and anthropogenic factors that may influence cortisol production associated with stress response. While some species, including coyotes (Canis latrans), have become commonplace in developed areas throughout North America, urban individuals still must navigate ever-changing, novel environments and cope with frequent disturbance. Given that coyotes are relatively large predators compared to most other urban wildlife, they face unique pressures such as crossing roadways to use suitable habitat fragments and are at a greater risk of being detected and experiencing negative human interactions. To assess whether urbanization influences hypothalamic-pituitary-adrenal axis activity in free-ranging coyotes, we analyzed cortisol concentration in hair samples from 97 coyotes residing across the urbanization gradient within the Greater Chicago Metropolitan area. As the proportion of developed landcover within coyote home ranges increased, coyotes experienced more stress. Body condition and social status also had strong relationships with stress. Animals in poorer body condition experienced more stress and subordinate coyotes experienced less stress than alphas. We also found some evidence that stress varied seasonally and among different age classes. Understanding how intrinsic and extrinsic factors influence endocrine activity in urban carnivores is vital for predicting how hormone production and related behavioral patterns may change in future populations as more areas become developed.

Changes in Fecal Glucocorticoid Metabolites in Captive Coyotes (Canis latrans): Influence of Gender, Time, and Reproductive Status

Reproduction is considered an energetically and physiologically demanding time in the life of an animal. Changes in physiological stress are partly reflected in changes in glucocorticoid metabolites and can be measured from fecal samples. We examined levels of fecal glucocorticoid metabolites (fGCMs) in 24 captive coyotes (Canis latrans) to investigate responses to the demands of reproduction. Using 12 pairs of coyotes (five pairs produced pups, seven pairs did not), we analyzed 633 fecal samples covering 11 biological periods (e.g., breeding, gestation, and lactation). Levels of fGCMs showed high individual variability, with females having higher fGCM levels than males. The production of pups showed no statistical effect on fGCM levels among females or males. Among females, fGCM levels were highest during 4-6 weeks of gestation compared to other periods but were not significantly different between pregnant and nonpregnant females. Among males, the highest fGCM levels were during 1-3 weeks of gestation compared to other periods, but were not significantly different between males with a pregnant mate versus nonpregnant mate. Of females producing pups, litter size did not influence fGCM levels. Given that they were fed ample food throughout the year, we found that the demands of producing pups did not appear to statistically influence measures of fGCM concentrations in captive coyotes.

Scavenging vs hunting affects behavioral traits of an opportunistic carnivore

Background

Human-induced changes to ecosystems transform the availability of resources to predators, including altering prey populations and increasing access to anthropogenic foods. Opportunistic predators are likely to respond to altered food resources by changing the proportion of food they hunt versus scavenge. These shifts in foraging behavior will affect species interactions through multiple pathways, including by changing other aspects of predator behavior such as boldness, innovation, and social structure.

Methods

To understand how foraging behavior impacts predator behavior, we conducted a controlled experiment to simulate hunting by introducing a prey model to captive coyotes (Canis latrans) and compared their behavior to coyotes that continued to scavenge over one year. We used focal observations to construct behavioral budgets, and conducted novel object, puzzle box, and conspecific tests to evaluate boldness, innovation, and response to conspecifics.

Results

We documented increased time spent resting by hunting coyotes paired with decreased time spent active. Hunting coyotes increased boldness and persistence but there were no changes in innovation. Our results illustrate how foraging behavior can impact other aspects of behavior, with potential ecological consequences to predator ecology, predator-prey dynamics, and human-wildlife conflict; however, the captive nature of our study limits specific conclusions related to wild predators. We conclude that human-induced behavioral changes could have cascading ecological implications that are not fully understood.

A meta-analysis of sex differences in animal personality: no evidence for the greater male variability hypothesis

The notion that men are more variable than women has become embedded into scientific thinking. For mental traits like personality, greater male variability has been partly attributed to biology, underpinned by claims that there is generally greater variation among males than females in non-human animals due to stronger sexual selection on males. However, evidence for greater male variability is limited to morphological traits, and there is little information regarding sex differences in personality-like behaviours for non-human animals. Here, we meta-analysed sex differences in means and variances for over 2100 effects (204 studies) from 220 species (covering five broad taxonomic groups) across five personality traits: boldness, aggression, activity, sociality and exploration. We also tested if sexual size dimorphism, a proxy for sex-specific sexual selection, explains variation in the magnitude of sex differences in personality. We found no significant differences in personality between the sexes. In addition, sexual size dimorphism did not explain variation in the magnitude of the observed sex differences in the mean or variance in personality for any taxonomic group. In sum, we find no evidence for widespread sex differences in variability in non-human animal personality.

Interface of Human/Wildlife Interactions: An Example of a Bold Coyote (Canis latrans) in Atlanta, GA, USA

There is arguably no other North American species that better illustrates the complexities of the human-wildlife interface than the coyote. In this study, a melanistic coyote in metropolitan Atlanta, Georgia was exhibiting unusually bold behaviors that included encounters with humans, domestic dogs, and attempts to enter homes. After tracking this coyote (nicknamed Carmine) across a highly urbanized landscape with participatory science, including at least 80 publicly reported sightings, he was captured and relocated to a wildlife sanctuary. Genome-wide analyses revealed 92.8% coyote ancestry, 1.7% gray wolf ancestry, and 5.5% domestic dog ancestry. The dog alleles in Carmine’s genome were estimated to have been acquired by his ancestors 14–29 years ago. Despite his bold behavior, Carmine did not carry any mutations known to shape hypersociability in canines. He did, however, carry a single copy of the dominant mutation responsible for his melanistic coat color. This detailed study of Carmine dispels common assumptions about the reticent coyote personality and the origins of behavior. His unusual bold behavior created a higher level of human-coyote interaction. He now serves as a public ambassador for human-wildlife coexistence, urging the global community to reconsider mythologies about wildlife and promote coexistence with them in landscapes significantly altered by human activity in our rapidly changing world.

Interactions with humans shape coyote responses to hazing

Medium and large carnivores coexist with people in urban areas globally, occasionally resulting in negative interactions that prompt questions about how to reduce human-wildlife conflict. Hazing, i.e., scaring wildlife, is frequently promoted as an important non-lethal means for urbanites to reduce conflict but there is limited scientific evidence for its efficacy. We used a population of captive coyotes (Canis latrans) to simulate urban human-coyote interactions and subsequent effects of hazing on coyote behavior. Past experiences with humans significantly affected the number of times a coyote approached a human to necessitate hazing. Coyotes that had been hand fed by adults had to be more frequently hazed than coyotes with other or no past experiences with adults. Past experience with children had no impact on the number of hazing events. The number of times a coyote approached an adult or child was reduced across days based on the accumulative number of times hazed, suggesting coyotes learn to avoid behaviors warranting hazing and that this could be used as a non-lethal management tool. However, prior experience and whether the interaction is with an adult or child can alter the outcomes of hazing and must be considered in determining the efficacy of hazing programs.

Persistence and conspecific observations improve problem-solving abilities of coyotes

Social learning has important ecological and evolutionary consequences but the role of certain factors, such as social rank, neophobia (i.e., avoidance of novel stimuli), persistence, and task-reward association, remain less understood. We examined the role of these factors in social learning by captive coyotes (Canis latrans) via three studies. Study 1 involved individual animals and eliminated object neophobia by familiarizing the subjects to the testing apparatus prior to testing. Studies 2 and 3 used mated pairs to assess social rank, and included object neophobia, but differed in that study 3 decoupled the food reward from the testing apparatus (i.e., altered task-reward association). For all three studies, we compared performance between coyotes that received a demonstration from a conspecific to control animals with no demonstration prior to testing. Coyotes displayed social learning during study 1; coyotes with a demonstrator were faster and more successful at solving the puzzle box but did not necessarily use the same modality as that observed to be successful. In study 2, there was no difference in success between treatment groups but this is likely because only one coyote within each pair was successful so successful coyote results were masked by their unsuccessful mate. In study 3, there was no difference in success between treatment groups; only two coyotes, both dominant, hand-reared males with demonstrators were able to perform the task. However, coyotes with a demonstrator were less neophobic, measured as latency to approach the object, and more persistent, measured as time spent working on the apparatus. Social rank was the best predictor of neophobia and persistence and was also retained in the best model for time to eat inside the apparatus, a post-trial measurement of object neophobia. These results suggest coyotes are capable of social learning for novel tasks but social rank, neophobia, and persistence influence their social-learning capabilities. This study contributes to understanding the mechanisms underlying how animals gain information about their environment.

The intrepid urban coyote: a comparison of bold and exploratory behavior in coyotes from urban and rural environments

Coyotes (Canis latrans) are highly adaptable, medium-sized carnivores that now inhabit nearly every large city in the United States and Canada. To help understand how coyotes have adapted to living in urban environments, we compared two ecologically and evolutionarily important behavioral traits (i.e., bold-shy and exploration-avoidance behavior) in two contrasting environments (i.e., rural and urban). Boldness is an individual’s reaction to a risky situation and exploration is an individual’s willingness to explore novel situations. Our results from both tests indicate that urban coyotes are bolder and more exploratory than rural coyotes and that within both populations there are individuals that vary across both spectrums. Bolder behavior in urban coyotes emerged over several decades and we speculate on possible processes (e.g., learning and selection) and site differences that could be playing a role in this behavioral adaptation. We hypothesize that an important factor is how people treat coyotes; in the rural area coyotes were regularly persecuted whereas in the urban area coyotes were rarely persecuted and sometimes positively rewarded to be in close proximity of people. Negative consequences of this behavioral adaptation are coyotes that become bold enough to occasionally prey on pets or attack humans.

Parental habituation to human disturbance over time reduces fear of humans in coyote offspring

A fundamental tenet of maternal effects assumes that maternal variance over time should have discordant consequences for offspring traits across litters. Yet, seldom are parents observed across multiple reproductive bouts, with few studies considering anthropogenic disturbances as an ecological driver of maternal effects. We observed captive coyote (Canis latrans) pairs over two successive litters to determine whether among‐litter differences in behavior (i.e., risk‐taking) and hormones (i.e., cortisol and testosterone) corresponded with parental plasticity in habituation. Thus, we explicitly test the hypothesis that accumulating experiences of anthropogenic disturbance reduces parental fear across reproductive bouts, which should have disparate phenotypic consequences for first‐ and second‐litter offspring. To quantify risk‐taking behavior, we used foraging assays from 5–15 weeks of age with a human observer present as a proxy for human disturbance. At 5, 10, and 15 weeks of age, we collected shaved hair to quantify pup hormone levels. We then used a quantitative genetic approach to estimate heritability, repeatability, and between‐trait correlations. We found that parents were riskier (i.e., foraged more frequently) with their second versus first litters, supporting our prediction that parents become increasingly habituated over time. Second‐litter pups were also less risk‐averse than their first‐litter siblings. Heritability for all traits did not differ from zero (0.001–0.018); however, we found moderate support for repeatability in all observed traits (r = 0.085–0.421). Lastly, we found evidence of positive phenotypic and cohort correlations among pup traits, implying that cohort identity (i.e., common environment) contributes to the development of phenotypic syndromes in coyote pups. Our results suggest that parental habituation may be an ecological cue for offspring to reduce their fear response, thus emphasizing the role of parental plasticity in shaping their pups’ behavioral and hormonal responses toward humans.

Mary CM. Does the use of a multi-trait, multi-test approach to measure animal personality yield different behavioural syndrome results?

A multi-trait, multi-test approach to investigate the convergence or discrimination between behavioural tests putatively targeting the same or different animal personality traits has been recommended, yet whether and how the approaches affect the identification of behavioural syndrome(s), the suite of correlated personality traits, requires investigation. Here, we used behavioural measures collected from five commonly used behavioural tests targeting three personality traits, evaluated their convergence/discrimination through exploratory factor analysis (EFA), and then explored whether the identification of syndrome changed based on the approach we used to quantify personality traits. Our results indicated that tests presumably targeting the same personality trait actually measured distinct behavioural aspects. Syndrome defined using correlation changed due to how we identified personality traits, but not when using structural equation models (SEMs). Overall, this study emphasizes that it is critical to clarify the approach and terms we use for ‘personality traits’ in the field of animal personality.

Olfactory attractants and parity affect prenatal androgens and territoriality of coyote breeding pairs

Hormones are fundamental mediators of personality traits intimately linked with reproductive success. Hence, alterations to endocrine factors may dramatically affect individual behavior that has subsequent fitness consequences. Yet it is unclear how hormonal or behavioral traits change with environmental stressors or over multiple reproductive opportunities, particularly for biparental fauna. To simulate an environmental stressor, we exposed captive coyote (Canis latrans) pairs to novel coyote odor attractants (i.e. commercial scent lures) mid-gestation to influence territorial behaviors, fecal glucocorticoid (FGMs) and fecal androgen metabolites (FAMs). In addition, we observed coyote pairs as first-time and experienced breeders to assess the influence of parity on our measures. Treatment pairs received the odors four times over a 20-day period, while control pairs received water. Odor-treated pairs scent-marked (e.g. urinated, ground scratched) and investigated odors more frequently than control pairs, and had higher FAMs when odors were provided. Pairs had higher FAMs as first-time versus experienced breeders, indicating that parity also affected androgen production during gestation. Moreover, repeatability in scent-marking behaviors corresponded with FGMs and FAMs, implying that coyote territoriality during gestation is underpinned by individually-specific hormone profiles. Our results suggest coyote androgens during gestation are sensitive to conspecific olfactory stimuli and prior breeding experience. Consequently, fluctuations in social or other environmental stimuli as well as increasing parity may acutely affect coyote traits essential to reproductive success.