Meeting with a male can lead to stress: female reaction to a pairing with a partner in Felidae

The aim of this study was to test the hypothesis that the level of sexual dimorphism modulates the effects of male-female social interaction on the female physiological condition in felids. We predicted that: 1 - contacts of females with males in species with low level of sexual dimorphism in body size will not lead to significant changes in the activity of the hypothalamus-pituitary-adrenal axis (female stress); 2 - contacts of females with males in species with a high level of sexual dimorphism can result in significant increase in the cortisol level in females. Our study did not support these hypotheses. Despite the fact that sexual dimorphism influenced partner relationships, changes of the activity of HPA in response to social interaction with a partner appeared to be determined by the biology of the species rather than by the degree of sexual dimorphism. In species with unexpressed sexual dimorphism in body size, females determined the character of relationships in the pair. In species with pronounced sexual dimorphism biased towards males, the pattern of relationships was determined by males. However, meeting a partner led to increased cortisol levels in females not in pairs with pronounced sexual dimorphism, but in pairs with a high frequency of partner interactions. This frequency was determined by the species life history and was probably related to the seasonality of reproduction and the degree of monopolization of the home range.

A systematic review of sex differences in rough and tumble play across non-human mammals

Abstract

It is widely believed that juvenile male mammals typically engage in higher rates of rough and tumble play (RTP) than do females, in preparation for adult roles involving intense physical competition between males. The consistency of this sex difference across diverse mammalian species has, however, not yet been systematically investigated, limiting our current understanding of its possible adaptive function. This review uses narrative synthesis to (i) evaluate the ubiquity of male-biased RTP across non-human mammals, (ii) identify patterns of variation within and between taxonomic groups, and (iii) propose possible predictors of variation in these differences, including methodological and socio-ecological factors, for investigation by future studies. We find that most species studied do exhibit higher rates or RTP in males than females, while female-biased RTP is rare. Sex differences are smaller and less consistent than expected, with many studies finding similar rates of RTP in males and females. We identify multiple potential socio-ecological predictors of variation in sex differences in RTP, such as intrasexual competition and dietary niche. However, variation is not strongly phylogenetically patterned, suggesting that methodological and environmental factors, such as sample size and play partner availability, are important to consider in future comparative analyses.

Significance statement

Rough and tumble play (RTP) is thought to be vital for developing physical skills necessary for aggressive competition in adulthood, explaining an apparently widespread sex difference in RTP in mammals whereby immature males are more likely to engage in this behaviour than females. However, no prior study has systematically investigated the extent to which a male bias in RTP is consistent across diverse mammalian species. We find that although RTP is commonly male biased, findings were highly variable both within- and between-species, and equal participation in RTP by males and females is more common than widely assumed. Our review suggests several potential predictors of variation in sex differences in RTP, particularly levels of intrasexual competition in both males and females. However, our findings also suggest the importance of considering methodological in addition to socio-ecological factors for future research.

The method matters: The effect of handling time on cortisol level and blood parameters in wild cats

Blood analysis has recently become a popular tool to assess the welfare of the wild cats. However, the estimates of blood parameters may depend on the sampling method. We have tested (1) if the sampling procedure influences blood parameters and (2) what parameters are the most efficient in assessing the physiological status in wild cat species. We assessed the effect of handling time on red blood cells (RBC) and white blood cells (WBC) counts, the ratio of neutrophils to lymphocytes (N/L ratio), and serum cortisol level within 1 hr after the capture of the animal in six far-east wild cats (Prionailurus bengalensis euptilura). Also, we analyzed literature data in 17 cat species to assess the effect of place of study, type of immobilization, and handling time on WBC count and N/L ratio. Serum cortisol level varied significantly with the handling time. RBC and WBC counts were strongly affected by the handling time. N/L ratio was very robust and did not depend on the handling time. However, the analysis of literature data has shown that the prolonged handling time (over 1 hr) and the type of immobilization significantly influence the N/L ratio, whereas the WBC count does not depend on any of considered factors. We conclude that while most blood parameters of cats are affected by routine handling time, the N/L ratio does not vary if the samples are collected within 1 hr after the capture of the animal. All other tested parameters should be treated with caution.