Abstract: Evidence is accumulating that cognitive abilities are shaped by the specific ecological conditions to which animals are exposed. Long-distance migratory birds may provide a striking example of this. Field observations have shown that, at least in some species, a substantial proportion of individuals return to the same breeding, wintering, and stopover sites in successive years. This observation suggests that migrants have evolved special cognitive abilities that enable them to accomplish these feats. Here we show that memory of a particular feeding site persisted for at least 12 months in a long-distance migrant, whereas a closely related nonmigrant could remember such a site for only 2 weeks. Thus, it seems that the migratory lifestyle has influenced the learning and memorizing capacities of migratory birds. These results build a bridge between field observations suggesting special memorization feats of migratory birds and previous neuroanatomical results from the same two species indicating an increase in relative hippocampal size from the first to the second year of life in the migrant but not in the nonmigrant.

Abstract: Experiments on imitation typically evaluate a student's ability to copy some feature of an expert's motor behavior. Here, we describe a type of observational learning in which a student copies a cognitive rule rather than a specific motor action. Two rhesus macaques were trained to respond, in a prescribed order, to different sets of photographs that were displayed on a touch-sensitive monitor. Because the position of the photographs varied randomly from trial to trial, sequences could not be learned by motor imitation. Both monkeys learned new sequences more rapidly after observing an expert execute those sequences than when they had to learn new sequences entirely by trial and error.

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: Feeding and training may affect acid-base responses to strenuous exercise. Acidosis usually correlates with higher blood lactate concentrations during intense exercise, but alkalosis has been found in several studies of horses, and higher lactate responses during sprints have been found in fat adapted horses. To elucidate these unexpected findings, we applied a comprehensive physicochemical approach to evaluate acid-base responses during exercise in fat adapted horses. In incremental tests and repeated sprints, changes in blood [H+] were dependent upon corresponding changes in pCO2 but not strong ion difference (SID, the algebraic sum of ions of sodium, potassium, chloride and lactate). The influence of changes in [Lac-] were largely offset by changes in [Na+], [K+] and [Cl-], so that SID was unchanged and did not contribute to the exercise induced acidemia, so it may be inaccurate to term this a lacticacidosis. During repeated sprints, central venous [H+] increased (acidosis) but arterial [H+] decreased (alkalosis). These changes were consistent with concurrent changes in venous and arterial pCO2 but not SID. Fat adaptation decreased mixed venous pCO2 during repeated sprints, which is consistent with the lower respiratory quotient associated with fat oxidation. Less pulmonary work to eliminate CO2 could benefit horses under hot and humid conditions, especially those with mildly reduced pulmonary function. The blood lactate response was decreased during aerobic tests but increased during anaerobic tests on fat adapted horses. Fat adaptation appears to facilitate the metabolic regulation of glycolysis, by sparing glucose and glycogen at work of low intensity, but by promoting glycolysis when power is needed for high intensity exercise. The blood lactate response to repeated sprints was increased more by the combination of fat adaptation and oral supplementation of sodium bicarbonate than by the sum of the responses to fat alone or bicarbonate alone. This synergism suggests that need for further studies of the interaction of fat adaptation with dietary cation-anion balance, especially under hot conditions. These results integrate harmoniously with previous findings of lower feed intake and fecal output, lower loads of heat and CO2, lower water losses in the feces and by evaporation, and less spontaneous activity and reactivity in fat adapted horses. Thus fat adaptation confers several advantages on horses and presumably other equids used for hard work, especially in the heat.

Abstract: Feral asses were studied on Volcano Alcedo, Galapagos Islands, Ecuador, during the wet season of 1980. On the volcano rim during March/April, two stable groups were observed to have a `female (harem) defense' polygynous mating system [Emlen, S.T., Oring, S.W., 1977. Ecology, sexual selection, and the evolution of mating systems. Science 197 (4300), pp. 215-223] and social behavior patterns and feeding ecology similar to feral asses living in a habitat where forage and climate are similar, e.g., Ossabaw Island, Georgia [Moehlman, P.D., 1979. Behavior and ecology of feral asses (Equus asinus). Nat. Geogr. Soc. Res. Rep., 1970, pp. 405-411; Moehlman, P.D., 1997. Feral asses (Equus africanus): intraspecific variation in social organization in arid and mesic habitats. J. Appl. Anim. Behav. Sci., this issue; McCort, W.D., 1980. The feral asses (Equus asinus) of Ossabaw Island, Georgia., PhD Dissertation, Pennsylvania State University, University Park, 219 pp.].