Female chimpanzees giving first birth in their natal group in Mahale: attention to incest between brothers and sisters

出自集団で出産するメスは「例外」ではないことを解明 --チンパンジー父系社会でメスが出自集団に居残る要因の検討--. 京都大学プレスリリース. 2021-01-15.Chimpanzee societies generally show male philopatry and female dispersal. However, demographic data on wild chimpanzee societies from long-term study sites have revealed that some females give birth in their natal group (i.e., “remaining females”). Here, we report two remaining females in the M group in Mahale, Tanzania, and compare their cases with previous reports to explore the social and ecological factors that lead to females remaining in their natal group. The results revealed that neither the social traits of the remaining females nor the ecological factors they experienced showed a coherent trend. However, we found multiple, non-mutually exclusive potential factors that may influence the decision by females to remain in their natal group: a decrease in indirect feeding competition, support from mothers or allomothers in the care of offspring and in aggressive interactions with other individuals, close relationships with the other remaining females, and a short adolescent infertility period. Additionally, we observed a natal female copulating with her older brother, which was the first observation of brother–sister incest in Mahale. Although DNA analysis revealed that her infant was not a product of inbreeding, the pair copulated frequently in the latter half of her estrus period, suggesting that they did not avoid incest behaviorally to avoid inbreeding. Furthermore, there was no hard evidence that the remaining female avoided mating with her maternal brother, suggesting that incest avoidance may not be a proximate factor responsible for female dispersal

Salivary Chromogranin A (CgA) Response to the Noradrenaline Transporter Blocker Atomoxetine in Dogs

Since salivary chromogranin A (CgA) is one of the known sympathetic adrenomedullar system (SAM) stress markers in humans and pigs, this study aimed to investigate whether salivary CgA in dogs reflects SAM activation. Our hypothesis was that salivary CgA would increase when central noradrenaline was pharmacologically induced. A selective noradrenaline transporter blocker, atomoxetine, was orally administered without causing any aversive responses in nine laboratory dogs to see if it would increase salivary CgA. Three treatment groups (i.e., atomoxetine, placebo, and pre-administration of a selective alpha-2 adrenoreceptor agonist (dexmedetomidine) followed by atomoxetine) were prepared with a randomized crossover design. Saliva sample collection, heart rate measurement and behavior observation were performed at Time 0 (baseline) and at 30, 60, 90 and 150 min after each treatment administration. The results demonstrated that salivary CgA significantly increased at 90 min in the atomoxetine treatment (p < 0.05), whereas it was not observed in the other two treatments. The present study showed that salivary CgA was increased by atomoxetine-induced SAM activation. However, this increase was blocked if dexmedetomidine was pre-administered. Overall, the results indicate that salivary CgA is a potential candidate for SAM-mediated stress markers in dogs. Further study to determine the dynamics of salivary CgA will be helpful in its practical use

育仔放棄されたネズミイルカの初乳の成分分析と人工哺育の試み

The harbor porpoise is a marine mammal rarely seen in aquariums. The ecology of this species is not well known, and captive breeding is difficult without essential information such as milk composition, amount consumed and frequency nursed per day, and lactation period. At the Otaru Aquarium in Japan, several deliveries of harbor porpoise offspring have occurred, but the calves have not survived. In the present study, we analyzed the colostrum of a harbor porpoise and attempted to hand-rear a calf using artificial milk after the mother denied nursing. The crude fat and crude protein contents of the colostrum were relatively high compared to values for other odontocetes. The present information will be helpful for future efforts to hand-rear harbor porpoises.本研究では，おたる水族館で育仔放棄されたネズミイルカ幼獣の人工哺育を試みた。生後14日で幼獣は死亡したが，母獣から貴重な初乳を得た。ハクジラ類の中でも本種は授乳期間が短いが，成分分析の結果，その初乳には粗脂肪と粗蛋白質が豊富に含まれていた