Abstract: The effect of short periods of strenuous exertion, in this case treadmill exercise, on the subsequent behavior of Standardbred horses was examined. Six horses were exercised on a high-speed treadmill 4 or 5 days per week, for 3-4 miles (approximately 1.8 m s-1 for 3 min, 5 m s-1 for 12 min, 9 m s-1 for 3 min, 3 m s-1 for 3 min, 1.8 m s-1 for 3 min). The behavior of the horses was observed in the horse's home stall immediately after exercise and 2-7 h after exercise. Focal animal sampling for a total of 150 h revealed that the horses spent significantly more time drinking and less time resting after exercise than they did on control (non-exercise or rest days). The greatest influence on behavior was seen immediately after exercise. The horses spent 13.2+/-2.7 s per 15 min drinking after exercise and 7.2+/-2.3 s per 15 min drinking on non-exercise days. They spent 7.3+/-1.5 min h-1 stand resting after exercise and 9.7+/-2.1 min h-1 on non-exercise days. These changes in behavior may be related to the physiological changes that accompany exercise. Eating, walking, elimination and self-grooming were not significantly influenced by exercise. In a second experiment the activities of two groups of six Standardbred mares were compared. One group was exercised on the treadmill and the other was not. The exercised horses spent more time drinking and lying, but urinated less than the non-exercised group.

Abstract: The prevailing assumption in the primate literature is that young or juvenile primates are more innovative than adult individuals. This innovative tendency among the young is frequently thought to be a consequence, or side effect, of their increased rates of exploration and play. Conversely, Reader and Laland's [International Journal of Primatology 22:787-806, 2001] review of the primate innovation literature noted a greater reported incidence of innovation in adults than nonadults, which they interpreted as (in part) a reflection of the greater experience and competence of older individuals. Within callitrichids there is contradictory evidence for age differences in response to novel objects, foods, and foraging tasks. By presenting novel extractive foraging tasks to family groups of callitrichid monkeys in zoos, we examined, in a large sample, whether there are positive or negative relationships of age with neophilia, exploration, and innovation, and whether play or experience most facilitates innovation. The results indicate that exploration and innovation (but not neophilia) are positively correlated with age, perhaps reflecting adults' greater manipulative competence. To the extent that there was evidence for play in younger individuals, it did not appear to contribute to innovation. The implications of these findings for the fields of innovation and conservation through reintroduction are considered.

Abstract: 1. Models on territory acquisition and tenure predict that territorial animals benefit by adjusting territorial defence behaviour to previous challenges they had experienced within the socially complex environment of communication networks. 2. Here, we addressed such issues of social cognition by investigating persisting effects of vocal contests on territory defence behaviour in nightingales Luscinia megarhynchos (Brehm). 3. Using interactive playback during nocturnal song of subjects, a rival was simulated to countersing either aggressively (by song overlapping) or moderately (by song alternating) from outside the subjects' territory. Thereby, the time-specific singing strategy provided an experimentally controlled source of information on the motivation of an unfamiliar rival. 4. Expecting that nightingales integrate information with time, the same rival was simulated to return as a moderately singing intruder on the following morning. 5. The results show that the vigour with which male nightingales responded to the simulated intrusion of an opponent during the day depended on the nature of the nocturnal vocal interaction experienced several hours before. 6. Males that had received the song overlapping playback the preceding night approached the simulated intruder more quickly and closer and sang more songs near the loudspeaker than did males that had received a song alternating playback. 7. This adjustment of territory defence strategies depending on information from prior signalling experience suggests that integrating information with time plays an important part in territory defence by affecting a male's decision making in a communication network.

Abstract: The ability to recognize oneself in a mirror is an exceedingly rare capacity in the animal kingdom. To date, only humans and great apes have shown convincing evidence of mirror self-recognition. Two dolphins were exposed to reflective surfaces, and both demonstrated responses consistent with the use of the mirror to investigate marked parts of the body. This ability to use a mirror to inspect parts of the body is a striking example of evolutionary convergence with great apes and humans.

Abstract: Humans are consciously aware of some memories and can make verbal reports about these memories. Other memories cannot be brought to consciousness, even though they influence behavior. This conspicuous difference in access to memories is central in taxonomies of human memory systems but has been difficult to document in animal studies, suggesting that some forms of memory may be unique to humans. Here I show that rhesus macaque monkeys can report the presence or absence of memory. Although it is probably impossible to document subjective, conscious properties of memory in nonverbal animals, this result objectively demonstrates an important functional parallel with human conscious memory. Animals able to discern the presence and absence of memory should improve accuracy if allowed to decline memory tests when they have forgotten, and should decline tests most frequently when memory is attenuated experimentally. One of two monkeys examined unequivocally met these criteria under all test conditions, whereas the second monkey met them in all but one case. Probe tests were used to rule out “cueing” by a wide variety of environmental and behavioral stimuli, leaving detection of the absence of memory per se as the most likely mechanism underlying the monkeys' abilities to selectively decline memory tests when they had forgotten.