No-Contact Microchip Monitoring of Body Temperature in Yearling Horses.

In clinics, temperature is used as an indicator of health. Mostly rectal temperature is recorded, requiring handling and time. Temperature-sensitive identification microchips could be an alternative. Foals (26 males and 17 females), 4-12 months old, were housed in stalls over two winters (December-February). They were equipped with an identification and temperature sensor microchip implanted in the neckline. Temperature was recorded using an antenna located near the drinking trough. Animals were fed concentrated feed and forage twice daily, with free access to water. Rectal temperatures (79 measurements) were recorded simultaneously in 26 animals. Data were analyzed with a linear mixed model, using natural cubic splines for the mean curve and a random horse effect. All animals remained healthy throughout the study. More than 100,000 recordings were obtained. Mean temperature for all individuals at all times was 37.5 ± 0.1°C. Time of the day affected temperature with a daily amplitude of 0.96°C (P < .001). Lowest temperatures were observed before dawn, the acrophase occurring around 18:00, with a smaller increase around midday. Mean temperature was 0.26°C higher in males (P < .05). It was also 0.1°C higher in light (<200 kg) compared with heavier foals (P < .001). Temperature decreased with increasing daylight (-0.35°C over the study period, P < .001). Microchip and rectal temperatures remained within normal limits and were significantly correlated (R2 = 0.16, P < .001). This noninvasive tool does not require extra-handling and will allow a better monitoring of normal body temperature values taking into consideration time of the day, meal time, and sex.

Human disturbances, habitat characteristics and social environment generate sex-specific responses in vigilance of Mediterranean mouflon.

In prey species, vigilance is an important part of the decision making process related to predation risk effects. Therefore, understanding the mechanisms shaping vigilance behavior provides relevant insights on factors influencing individual fitness. We investigated the role of extrinsic and intrinsic factors on vigilance behavior in Mediterranean mouflon (Ovis gmelini musimon×Ovis sp.) in a study site spatially and temporally contrasted in human pressures. Both sexes were less vigilant in the wildlife reserve compared to surrounding unprotected areas, except for males during the hunting period. During this period, males tended to be less strictly restricted to the reserve than females what might lead to a pervasive effect of hunting within the protected area, resulting in an increase in male vigilance. It might also be a rutting effect that did not occur in unprotected areas because males vigilance was already maximal in response to human disturbances. In both sexes, yearlings were less vigilant than adults, probably because they traded off vigilance for learning and energy acquisition and/or because they relied on adult experience present in the group. Similarly, non-reproductive females benefited of the vigilance effort provided by reproductive females when belonging to the same group. However, in the absence of reproductive females, non-reproductive females were as vigilant as reproductive females. Increasing group size was only found to reduce vigilance in females (up to 17.5%), not in males. We also showed sex-specific responses to habitat characteristics. Females increased their vigilance when habitat visibility decreased (up to 13.8%) whereas males increased their vigilance when feeding on low quality sites, i.e., when concomitant increase in chewing time can be devoted to vigilance with limited costs. Our global approach was able to disentangle the sex-specific sources of variation in mouflon vigilance and stressed the importance of reserves in managing and conserving wild sheep populations.