Reproductive performance and gestational effort in relation to dietary fatty acids in guinea pigs

Background： Dietary saturated（SFAs） and polyunsaturated（PUFAs） fatty acids can highly affect reproductive functions by providing additional energy, modulating the biochemical properties of tissues, and hormone secretions. In precocial mammals such as domestic guinea pigs the offspring is born highly developed. Gestation might be the most critical reproductive period in this species and dietary fatty acids may profoundly influence the gestational effort. We therefore determined the hormonal status at conception, the reproductive success, and body mass changes during gestation in guinea pigs maintained on diets high in PUFAs or SFAs, or a control diet.Results： The diets significantly affected the females＇ plasma fatty acid status at conception, while cortisol and estrogen levels did not differ among groups. SFA females exhibited a significantly lower body mass and litter size, while the individual birth mass of pups did not differ among groups and a general higher pup mortality rate in larger litters was diminished by PUFAs and SFAs. The gestational effort, determined by a mother＇s body mass gain during gestation, increased with total litter mass, whereas this increase was lowest in SFA and highest in PUFA individuals. The mother＇s body mass after parturition did not differ among groups and was positively affected by the total litter mass in PUFA females.Conclusions： While SFAs reduce the litter size, but also the gestational effort as a consequence, PUFA supplementation may contribute to an adjustment of energy accumulations to the total litter mass, which may both favor a mother＇s body condition at parturition and perhaps increase the offspring survival at birth.

Tourism may trigger physiologically stress response of a long-term habituated population of golden snub-nosed monkeys

Wildlife tourism is a thriving form of nature-based tourism that can provide revenue for conservation funds,and increase public awareness of biodiversity conservation(Xiang et al.2011).Tourism,however,may induce behavioral and physiological stress responses on animals(Marechal 2015;Beehner and Bergman 2017).Part of the physiological stress response is increased activity of the hypothalamic-pituitary-adrenal(HPA)axis,resulting in the systemic elevation of glucocorticoids.An increase of glucocorticoids in the bloodstream leads to rapid mobilization of stored energy reserves and inhibitions of nonimmediately critical activities like growth,reproduction,and digestion in response to environmental challenges(Beehner and Bergman 2017).

Mate assessment behavior is correlated to learning ability in female threespine sticklebacks

In many species, males signal quality with elaborate traits, but females often show inter-individual variation in pref ere nee for these traits. Choosi ng a mate requires multiple cog nitive steps;therefore, cog nitive style (how an in dividual processes information) likely in fluences the perception of sexual signals and ability to choose a high-quality mate. An important component of cognitive style is flexibility;cognitively flexible individuals are more perceptive to shifts in cues. We hypothesized that cognitively flexible individuals would acquire more information about potential mates, better discern between two quality-signaling traits, and thus be more discriminatory. Here, we show that mate assessment is correlated to other cognitive traits. Although we did not detect an effect of cogn itive style on mate pref ere nee or discriminatio n, we found that female threespi ne sticklebacks Gasterosteus aculeatus that spent more time assessing potential mates (more responsive) in a dichotomous mate choice task reached both the initial and reversal learning criterion in a spatial learning task with fewer errors. However, these highly responsive females made more consecutive mistakes immediately at the beginning of the reversal phase, suggest!ng that they did not quickly adapt to the en vironmental cha nge but in stead rapidly formed strict routi nes duri ng the learning task that were eventually reversible after repeated errors. Furthermore, we found evidenee for condition-dependent mate pref ere nee, with larger females preferring the high-quality male. These are among the first results that illustrate how cog nitive traits might in flue nee mate choice, which has implicati ons for the st re ngth and di recti on of sexual selection.