“…We observed such a tendency in this study, but the difference was not statistically significant. This is comparable to the results of Debeffe et al (2015b) in roe deer, where a similar nonsignificant trend in the repeatability of another behavioural trait (docility) was observed. Power to detect biologically meaningful differences in repeatability in wild populations such as in the current study is arguably low.…”
Antipredator behaviours can be lost relatively quickly in populations that are relieved of predation, as is known for several species inhabiting islands. Flight initiation distance (FID) is often studied in the context of island tameness; however, little is known about the factors that influence and maintain FID variation in predation-free populations. Here, we studied FID in foals of an isolated predator-free population of feral horses (Equus caballus L., 1758) on Sable Island, Canada, to determine if FID could be used for research on consistent individual differences in risk aversion and island tameness. In addition to testing for temporal, spatial, and sex effects on FID, we compared repeatability estimates at two temporal scales (within and among days). Similar FID for measurements obtained on the same day and for males and females indicated an absence of short-term desensitization and sex effects. In contrast, FID decreased for measurements made on subsequent days and from east to west, which could reflect habituation to human presence and (or) other temporal and spatial processes. Repeatability was high (0.42 ± 0.06), but tended to decrease with increasing time intervals. This study highlights the potential of FID for individual-based research on the ecology and evolutionary dynamics of risk aversion in predation-free populations.Key words: boldness, Equus caballus, fear, horse, personality, risk aversion, temperament.Résumé : Les comportements anti-prédateurs peuvent disparaître assez rapidement dans les populations ne faisant plus l'objet de prédation, comme cela est le cas pour plusieurs espèces habitant des îles. La distance de fuite (DF) est souvent étudiée dans le contexte de la docilité insulaire; cependant, les connaissances sur les facteurs qui influencent et maintiennent les variations de la DF dans les populations sans prédateurs sont toutefois limitées. Nous avons étudié la DF chez des poulains d'une population de chevaux feraux (Equus caballus L., 1758) isolée et sans prédateurs à l'île de Sable (Canada) pour déterminer si la DF peut être utilisée pour étudier les différences individuelles sur le plan de l'aversion au risque et de la docilité insulaire. En plus de vérifier la présence d'effets temporels, spatiaux et du sexe sur la DF, nous avons comparé des estimations de la répétabilité à deux échelles temporelles (durant une même journée et sur plusieurs jours). Des DF semblables pour des mesures obtenues le même jour et pour les mâles et les femelles indiquent l'absence de désensibilisation à court terme et d'effets du sexe. Par contre, la DF diminuait pour des mesures prises sur plusieurs jours et de l'est vers l'ouest, ce qui pourrait refléter une habituation à la présence d'humains ou d'autres processus temporels ou spatiaux. La répétabilité était élevée (0,42 ± 0,06), mais tendait à diminuer pour des intervalles de temps plus grands. L'étude fait ressortir le potentiel que présente la DF pour l'étude reposant sur les individus de l'écologie et la dynamique de l'évolution de l'...
“…We observed such a tendency in this study, but the difference was not statistically significant. This is comparable to the results of Debeffe et al (2015b) in roe deer, where a similar nonsignificant trend in the repeatability of another behavioural trait (docility) was observed. Power to detect biologically meaningful differences in repeatability in wild populations such as in the current study is arguably low.…”
Antipredator behaviours can be lost relatively quickly in populations that are relieved of predation, as is known for several species inhabiting islands. Flight initiation distance (FID) is often studied in the context of island tameness; however, little is known about the factors that influence and maintain FID variation in predation-free populations. Here, we studied FID in foals of an isolated predator-free population of feral horses (Equus caballus L., 1758) on Sable Island, Canada, to determine if FID could be used for research on consistent individual differences in risk aversion and island tameness. In addition to testing for temporal, spatial, and sex effects on FID, we compared repeatability estimates at two temporal scales (within and among days). Similar FID for measurements obtained on the same day and for males and females indicated an absence of short-term desensitization and sex effects. In contrast, FID decreased for measurements made on subsequent days and from east to west, which could reflect habituation to human presence and (or) other temporal and spatial processes. Repeatability was high (0.42 ± 0.06), but tended to decrease with increasing time intervals. This study highlights the potential of FID for individual-based research on the ecology and evolutionary dynamics of risk aversion in predation-free populations.Key words: boldness, Equus caballus, fear, horse, personality, risk aversion, temperament.Résumé : Les comportements anti-prédateurs peuvent disparaître assez rapidement dans les populations ne faisant plus l'objet de prédation, comme cela est le cas pour plusieurs espèces habitant des îles. La distance de fuite (DF) est souvent étudiée dans le contexte de la docilité insulaire; cependant, les connaissances sur les facteurs qui influencent et maintiennent les variations de la DF dans les populations sans prédateurs sont toutefois limitées. Nous avons étudié la DF chez des poulains d'une population de chevaux feraux (Equus caballus L., 1758) isolée et sans prédateurs à l'île de Sable (Canada) pour déterminer si la DF peut être utilisée pour étudier les différences individuelles sur le plan de l'aversion au risque et de la docilité insulaire. En plus de vérifier la présence d'effets temporels, spatiaux et du sexe sur la DF, nous avons comparé des estimations de la répétabilité à deux échelles temporelles (durant une même journée et sur plusieurs jours). Des DF semblables pour des mesures obtenues le même jour et pour les mâles et les femelles indiquent l'absence de désensibilisation à court terme et d'effets du sexe. Par contre, la DF diminuait pour des mesures prises sur plusieurs jours et de l'est vers l'ouest, ce qui pourrait refléter une habituation à la présence d'humains ou d'autres processus temporels ou spatiaux. La répétabilité était élevée (0,42 ± 0,06), mais tendait à diminuer pour des intervalles de temps plus grands. L'étude fait ressortir le potentiel que présente la DF pour l'étude reposant sur les individus de l'écologie et la dynamique de l'évolution de l'...
“…Our results provide evidence for the emergence of personality and phenotypic syndromes in early life history, as similarly shown in other mammals (European roe deer, Capreolus capreolus , Debeffe et al, ; dwarf hamsters, Phodopus sungorus , Kanda, Louon, & Straley, ), fish (convict cichlids, Amatitlania siquia , Mazué, Dechaume‐Moncharmont, & Godin, ), and reptiles (red‐eared slider turtles, Trachemys scripta , Carter, Paitz, McGhee, & Bowden, ). Phenotypic correlations among traits were substantially influenced by cohort identity, which suggest that the emergence of behavior‐endocrine syndromes in coyote pups is attributed to litter identity (Table ).…”
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.
“…Although there was some support for an effect of the two-way interaction between sex and log(Ncaptures), the sex difference in slopes for the effect of the number of captures within a winter on handling score was not biologically informative as it was mainly driven by a small difference in score at first capture (i.e. 2.3 ± 0.1 and 1.9 ± 0.1 for females and males, respectively), as previously documented (Debeffe et al 2015). Fig.…”
Section: Resultsmentioning
confidence: 58%
“…docility, was also assessed for each individual by a single experienced handler. The occurrence and intensity of several behavioral components (notably, vocalization, struggling and kicking) were used to index docility during manipulation (see more details in Debeffe et al 2015). The resulting handling score ranged from 0 to 4, with 0 indicating docile individuals, while 4 indicates non-docile, highly stressed individuals.…”
Faced with rapid environmental changes, individuals may express different magnitude and plasticity in their response to a given stressor. However, little is known about the causes of variation in phenotypic plasticity of the stress response in wild populations. In the present study, we repeatedly captured individual roe deer (Capreolus capreolus) from two wild populations in Sweden exposed to differing levels of predation pressure and measured plasma concentrations of stress-induced cortisol and behavioral docility. While controlling for the marked effects of habituation, we found clear between-population differences in the stress-induced cortisol response. Roe deer living in the area that was recently recolonized by lynx (Lynx lynx) and wolves (Canis lupus) expressed cortisol levels that were around 30% higher than roe deer in the human-dominated landscape free of large carnivores. In addition, for the first time to our knowledge, we investigated the stress-induced cortisol response in free-ranging newborn fawns and found no evidence for hypo-responsiveness during early life in this species. Indeed, stress-induced cortisol levels were of similar magnitude and differed between populations to a similar extent in both neonates and adults. Finally, at an individual level, we found that both cortisol and docility levels were strongly repeatable, and weakly negatively inter-correlated, suggesting that individuals differed consistently in how they respond to a stressor, and supporting the existence of a stress-management syndrome in roe deer.Electronic supplementary materialThe online version of this article (10.1007/s00442-018-4174-7) contains supplementary material, which is available to authorized users.
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