Abstract: Father-daughter matings and its avoidance mechanism were analysed on the basis of data which gained from behavioural observations and paternity tests in Misaki feral horses from 1979 to 1994. Twelve stallions and their 51 daughters had 176 breeding seasons, but they lived in the different home range in 82 breeding seasons. About half of 1- to 3-year-old mares emigrated from natal area to the other and grew up there. Therefore, emigrations of young mares may result reduction of contacts and avoidance of inbreeding with their fathers. The stallions and their daughters lived in the same area in 94 breeding seasons, but there were no cases that daughters which left their natal harem groups before sexual maturity formed again stable consort relations with their natal harem stallions. It is possible that separation of young mares from their natal groups before sexual maturity may result avoidance of formation of consort relation with their fathers. Two father-daughter matings were observed in 124 paternity tests. These two daughters were born in the other harem groups than their father's and left their natal groups before maturity. After maturity, one of them formed a stable consort relation with her father and the other remained together with her father for 2 months in the breeding season. Both of them had not experience to have lived with their fathers before maturity. The persent result supports the hypothesis in wild and semi-wild horses that inbreedings between fathers and daughters may be avioded by the experience to have lived together before sexual maturity.

Abstract: Non-invasive faecal oestrogen and progesterone metabolite evaluations are well established approaches for monitoring reproductive function in a variety of mammalian species. The route of excretion of steroid hormone metabolites varies considerably among species, and also between steroids within the same species. Steroid concentrations in faeces exhibit a similar pattern to those in plasma, but have a lag time, which depending upon the species, can be from 12 h to more than 2 days. Faecal steroid metabolites in mammals are mainly unconjugated compounds. Faecal oestrogens consist predominantly of oestrone and/or oestradiol-17α or -17β. Therefore, specific oestrogen antibodies or antibodies against total oestrogens can be used for their determination. Progesterone is metabolised to several 5α- or 5β-reduced pregnanediones and hydroxylated pregnanes prior to its faecal excretion. Therefore, relevant antibodies for their determination show considerable cross-reactivities with several pregnane metabolites, whereas specific progesterone antibodies are less suitable. Faecal oestrogen evaluations have been used as reliable indicators of pregnancy in several ungulate and some primate species. They have also been used to determine the preovulatory period in carnivores, corpus luteum activity in New World primates, and to diagnose cryptorchidism in horses. Faecal progesterone metabolite analysis has been successfully used for monitoring corpus luteum function and pregnancy, abortion, seasonality and treatment therapies in an ever expanding list of species.

Abstract: Evidence for a visual field advantage (VFA) in the face perception of chimpanzees was investigated using a modification of a free-vision task. Four of six chimpanzee subjects previously trained on a computer joystick match-to-sample paradigm were able to distinguish between images of neutral face chimeras consisting of two left sides (LL) or right sides (RR) of the face. While an individual's ability to make this distinction would be unlikely to determine their suitability for the VFA tests, it was important to establish that distinctive information was available in test images. Data were then recorded on their choice of the LL vs. RR chimera as a match to the true, neutral image; a bias for one of these options would indicate an hemispatial visual field advantage. Results suggest that chimpanzees, unlike humans, do not exhibit a left visual field advantage. These results have important implications for studies on laterality and asymmetry in facial signals and their perception in primates.

Abstract: After Charles Darwin's The Expression of the Emotions in Man and Animals, published in 1872, we had to wait 60 years before the theme of animal expressions was picked up by another astute observer. In 1935, Nadezhda Ladygina-Kohts published a detailed comparison of the expressive behavior of a juvenile chimpanzee and of her own child. After Kohts, we had to wait until the 1960s for modern ethological analyses of primate facial and gestural communication. Again, the focus was on the chimpanzee, but ethograms on other primates appeared as well. Our understanding of the range of expressions in other primates is at present far more advanced than that in Darwin's time. A strong social component has been added: instead of focusing on the expressions per se, they are now often classified according to the social situations in which they typically occur. Initially, quantitative analyses were sequential (i.e., concerned with temporal associations between behavior patterns), and they avoided the language of emotions. I will discuss some of this early work, including my own on the communicative repertoire of the bonobo, a close relative of the chimpanzee (and ourselves). I will provide concrete examples to make the point that there is a much richer matrix of contexts possible than the common behavioral categories of aggression, sex, fear, play, and so on. Primate signaling is a form of negotiation, and previous classifications have ignored the specifics of what animals try to achieve with their exchanges. There is also increasing evidence for signal conventionalization in primates, especially the apes, in both captivity and the field. This process results in group-specific or “cultural” communication patterns.