Abstract: We observed the species and numbers of mobbing birds and their effects on a large, nocturnal, bird-eating predator, the powerful owl, together with the pattern of owl predation on mobbing and non-mobbing species. Owls were mobbed on 35 occasions by seven of 44 species of forest birds at a site composed of open forest (88% by area) and rainforest (12%). The majority of bouts involved individuals of a single species, although mixed groups were observed on nine occasions. Regular mobbers were between 4 and 26% of the owls' body weight. Owls abandoned their daytime roosts during 20% of bouts and responded by calling or actively monitoring mobbers during 54% of bouts. Mobbing appeared to explain why owls roosted in rainforest significantly more often than expected by its availability, mobbing being significantly less frequent in rainforest than in open forest. Only one mobbing species regularly occupied rainforest and the canopy of roosts in rainforest was denser than that in open forest, thus reducing the chances of an owl being detected by potential mobbers. Twelve species of forest birds were within the range of prey size of the powerful owl (75-800 g): six were mobbers and six non-mobbers. The frequency of owl predation on non-mobbers was 8.75 times that on mobbers. The species in this study took a high risk by mobbing a very large predator, but benefited by greatly reducing their chances of predation.

Abstract: The pressures of developing and maintaining intricate social relationships may have led to the evolution of enhanced cognitive abilities in many nonhuman primates. Knowledge of the dominance ranks and social relationships of other individuals, in particular, is important in evaluating one's position in the rank hierarchy and affiliative networks. Triadic interactions offer an excellent opportunity to examine whether decisions are taken by individuals on the basis of such knowledge. Allogrooming supplants among wild female bonnet macaques (macaca radiata) usually involved the subordinate female of a grooming dyad retreating at the approach of a female dominant to both members of the dyad. In a few exceptional cases, however, the dominant member of the dyad retreated; simple non-cognitive hypotheses involving dyadic rank differences and agonistic relationships failed to explain this phenomenon. Instead, retreat by the dominant individual was positively correlated with the social attractiveness of her subordinate companion (as measured by the duration of grooming received by the latter from other females in the troop). This suggests that not only does an individual evaluate relationships among other females, but does so on the basis of the amount of grooming received by them. Similarly, the frequency of approaches received by any female was correlated with her social attractiveness when she was the dominant member of the dyad, but not when she was the subordinate. This indicated that approaching females might be aware of the relative dominance ranks of the two allogrooming individuals. In logistic regression analyses, the probability of any individual retreating was found to be influenced more by her knowledge of her rank difference with both the other interactants, rather than by their absolute ranks. Moreover, information about social attractiveness appeared to be used in terms of correlated dominance ranks. The nature of knowledge acquired by bonnet macaque females may thus be egotistical in that other individuals are evaluated relative to oneself, integrative in that information about all other interactants is used simultaneously, and hierarchical in the ability to preferentially use certain categories of knowledge for the storage of related information from other domains.

Abstract: Awareness varies between different species and humans can never truly appreciate what it is like to be another individual, either of the same species or another. Visual perceptual faculties provide some evidence of the extent to which domesticated animals derive information from objects in their environment, whilst changes in behaviour resulting from different visual stimuli can also provide valuable information on the state of visual awareness. Extensive processing of potentially visual information must occur in all domesticated species, but is much less well understood than purely sensory based information. For example, sensory aspects of colour vision are reasonably well understood, but the role of wavelength variables in an animal's cognition and its colour experience is not clear. Considerable use is made of diurnal changes in photoperiod to synchronise endogenous rhythms to particular times of the day and the year. Variation in light intensity in natural images is also important for social reasons for animals to be able to discriminate between, e.g., different faces, but little is known about intensity preferences or the effects of intensity on behaviour. It appears likely that in many cases visual stimuli represent some of the most important influences on an animal's awareness, either alone or in combination with, e.g., olfactory cues. However, a much greater understanding of their processing is required before we can make useful deductions about visual awareness in domesticated animals.

Abstract: Conventional wisdom over the past 160 years in the cognitive and neurosciences has assumed that brains evolved to process factual information about the world. Most attention has therefore been focused on such features as pattern recognition, color vision, and speech perception. By extension, it was assumed that brains evolved to deal with essentially ecological problem-solving tasks. © 1998 Wiley-Liss, Inc.