Abstract: Twelve colts and 12 fillies were observed during their first 2 years of life. Data on the foal's nearest neighbor, distance to dam and stallion, and time budget were compiled by age. The birth of one foal was witnessed. During their first month of life, Przewalski foals were dependent on the dam. She provided most of their nourishment and foals spent 54% of their time within 1 m of her. The biggest change in behavior of foals occurred between Months 1 and 2. The amount of time spent resting and nursing declined, while the amount of time spent foraging increased sharply. Foals began to leave their mothers and interact with peers by 3 weeks of age, and at 2 months they were interacting with older herd members. By 5 months of age, the amount of time spent in most behaviors was identical to that of adults, except that vocalization rates and involvement in aggression were lower than for adults. Juveniles spent less time stand-resting than adults throughout their first year, but more time in recumbent rest. Foals spent far less time with their sire than with their dam. However, an orphaned foal spent more time with his sire than did mothered foals, indicating that the sire assumed part of the role of the missing dam.

Abstract: A study was made of the behavior of young male Misaki feral horses in the developmental stage, by observing nine of them once a week from January 1988 to December 1996. The relationship between behavior before separation and in the developmental stage was also investigated. This stage begins just after young males separate from their natal band or mothers, and it continues until they start to form harems. The duration of the developmental stage in the study ranged from 0.6 to 3.9 years, depending on the age of the young males at the time of separation. Young males associated with three types of social groups at the beginning of the developmental stage, according to their social groups before separation. These were bachelor groups, harem groups and wandering female groups. During this period, males joined the three groups, mixed sex groups and sometimes were solitary. It was considered that these associations provided a good opportunity for males to acquire different behavioral patterns and experiences before they entered the next stage. Depending on the groups with which they associated, young males that spent more time with bachelor groups had the longest average developmental stage. They associated with harem groups more often during the breeding season and more frequently with other groups or were solitary during the non-breeding season. This may be a transition period because by the end of this stage all males had spent time in solitude before forming their own harem bands.

Abstract: The term `leadership' has been used in several different senses, resulting in very different ways of identifying leaders and apparently inconsistent conclusions on how leadership is determined in herbivores. We therefore propose the following definitions: (i) a leader is the individual that is consistently the one who initiates long-distance, spontaneous group movements toward a new feeding site and (ii) long-distance spontaneous group movements are movements which happen when an animal changes activity and location and is immediately followed by a similar change in activity and location by other members of the group. Using these definitions, we tested for consistency of movement order across time and situation within a group of fifteen 2-year-old heifers. We found that the same individual was recorded as the very first animal in 48% of movements toward a new feeding site and could therefore be identified as the `leader'. We also showed that movement order when the animals entered an experimental plot, or progressed slowly through the field during a grazing bout, did not produce the same result. This method, which enables us to identify leaders in groups of animals at pasture, should improve our knowledge of how leadership is determined in grazing herbivores.

Abstract: Temperament traits in animals may have important fitness consequences, but have received little attention from ecologists or evolutionary biologists. A few studies have linked variation in temperament with fitness, but none has measured selection on temperament traits. We estimated the strength of selection on female boldness and docility on bighorn sheep ewes, Ovis canadensis. The Ram Mountain population experienced little predation pressure during the first 25 years of study, then 2 years (1997 and 1998) of frequent predation by cougars, Puma concolor, during which adult ewe mortality almost tripled over the long-term average, to 27% a year. During years of high predation, we found moderate selection favouring bold ewes, and age-specific selection on docility. Old ewes appeared more vulnerable to predation than young ewes. In contrast, no evidence of selection on temperament traits was observed during 2 years of low predation (1996 and 1999). These results suggest predator-induced selection favouring bold and nondocile ewes. Leadership was highly correlated with age and may increase the risk of predator encounter. Leadership alone, however, could not explain the higher vulnerability of old ewes to predation. Cougar predation on bighorn sheep occurs sporadically and unpredictably, probably because individual cougars often are prey specialists. Cougar predation may have limited microevolutionary effects on temperament in bighorn sheep, because it mostly affects ewes near the end of their reproductive life span and because of potential countervailing selection on boldness and docility. Copyright 2003 Published by Elsevier Science Ltd on behalf of The Association for the Study of Animal Behaviour.

Abstract: Social relationships of 30 N'dama cows during supplementary feeding, post-grazing, were studied over a period of 1.5 years. Dominance ranks determined during idling and feeding periods were strongly correlated (Spearman's rank correlation (rs = 0.964, P < 0.01). The number of animals dominated by a cow during feeding was strongly (P < 0.01) related to liveweight (r = 0.822) and age (r = 0.755). Low status cows ate less frequently than medium and high status animals, while middle ranking cows were ejected more frequently from the feed trough than other dominance groups. Animals had preferences in the use of feed troughs, with social rank being the dominant factor determining the location of feed trough space used. Cows of similar status were generally preferred feeding and movement neighbours and antagonists. However, the dominance rank of an animal and its preferred neighbour during idling were not significantly correlated (rs = 0.220, P > 0.05). Voluntary leadership ranks into and out of the pen were, respectively, related closely (P < 0.01) to feeding dominance ranks (rs = 0.661, 0.640) and idling dominance ranks (rs = 0.621, 0.669).