Not by the same token: A female orangutan (Pongo pygmaeus) is selectively prosocial.

Studies of prosocial behavior in nonhumans have focused on group-living social animals. Despite being highly social and closely related to humans, chimpanzees have rarely exhibited prosocial preferences in experimental tasks. Fewer studies have provided their non group-living relatives-orangutans-with the opportunity to express prosocial preferences. Here, we allowed a single female orangutan to provide rewards for herself and for her mother, sister, or both, across various phases, using a token economy task. The orangutan was more likely to choose prosocially when she could provide rewards to her sister and herself compared to when she could provide rewards to her mother and herself. However, when presented with the simultaneous options of providing rewards for self, self and mother, or self and sister, she chose prosocially equally often to her mother and sister. She made the largest number of prosocial choices in a phase when she could provide rewards to all participants (herself, her sister, and her mother) rather than providing rewards only to herself or only to herself and one other participant. Despite the obvious limitations of a single case study, the study adds to the limited information on prosocial preferences in less social primate species, particularly when given the chance to share food items with different kin.

Rating vs. coding in animal personality research.

Animal personality research has become increasingly popular over the past few decades. The two main methods used to examine individual differences in animals are rating and coding. The rating method involves human scoring of an animal's behavioral tendencies along various behavioral dimensions, such ratings are typically based on the human rater's experience with the animal. The coding method also requires humans to score an animal's behavior, but differs in that the scoring is based on the animal's immediate behavior in a specific context. This brief report describes the use of both the rating and coding methods to examine personality within a group of 10 Garnett's bushbabies (Otolemur garnettii). The results indicated that individual personalities do exist in bushbabies, but also suggested that the rating method is heavily influenced by the rater's experience with an animal. Consequently, it is important that the nature of the rater's interactions with the target animals be considered when using the rating method to assess animal personality.

Efficacy of auditory enrichment in a prosimian primate (Otolemur garnettii).

Research suggests that auditory environmental enrichment might reduce abnormal behavior in certain primate species. The authors evaluated the behavioral effects of exposure to music in a prosimian primate (Garnett's bushbaby; Otolemur garnettii). They exposed bushbabies to a Mozart concerto for 15 min per day for 20 d (5 h exposure total), video-recorded them and subsequently analyzed the frequency of subjects' grooming and stereotypic behaviors. The authors compared the data with baseline behavioral data that had been recorded over a 20-d period before the experimental treatment. Neither stereotypy nor grooming behavior varied as a result of exposure to music. These results do not support the hypothesis that auditory enrichment in the form of exposure to music is an effective means of reducing stereotypic behavior in O. garnettii.