Testing three primate species' attentional biases toward preferred and unpreferred foods: Seeing red or high valued food?

Animals navigate complex environments that present both hazards and essential resources. The prioritization of perceptual information that is relevant to their next actions, such as accessing or avoiding different resources, poses a potential challenge to animals, one that can impact survival. While animals' attentional biases toward negatively valanced and threatening stimuli have been explored, parallel biases toward differently valued resources remain understudied. Here, we assessed whether three primate species (chimpanzees [Pan troglodytes], gorillas [Gorilla gorilla gorilla], and Japanese macaques [Macaca fuscata]) prioritized their attention to positively valued resources-preferred foods compared to unpreferred foods. We employed a computerized dot probe attentional bias task in which we presented participants with paired images of their preferred and unpreferred foods in randomized locations (left or right). Latencies to touch the "probe" that replaced either image revealed that all three species responded faster to the probe when it replaced the preferred option (χ²(1) = 284.50, SE² = .03, p < .001). The uniformity of the primates' responses hints that a propensity to prioritize highly preferred items is rooted in these primates' evolutionary past, one that may serve as a mechanism to rapidly detect and locate resources such as highly valued foods. Future research will help disentangle the role that color plays in these biases. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

A 25-Year Retrospective Review of Mortality in Chimpanzees (Pan troglodytes) in Accredited U.S. Zoos from a Management and Welfare Perspective.

Understanding causes of death allows adjustment of health management strategies for animals in managed care. From 224 documented chimpanzee deaths occurring from 1995 to 2019 in 42 accredited U.S. zoos, post-mortem records and necropsy reports were analyzed for the primary cause of death, which were available for 214 individuals. In total, 37 cases of stillbirth and neonatal deaths were assessed (16.5%); however, the focus was otherwise placed on the remaining 177 cases in which the death occurred in individuals aged greater than 1 month. There were no sex-related differences in etiology; however, age variation in the cause of death was statistically significant (p < 0.001). Elderly (35 years and older) chimpanzees tended to die of intrinsic, often degenerative, etiologies, whereas infants, juveniles, and adolescents (less than 15 years) were more likely to be involved in fatal trauma. Overall, there were 27 deaths (15.3% of all post-neonatal deaths) related to trauma and 13 of these were directly or indirectly related to conspecific aggression. Understanding causes of mortality and the interrelation with management can benefit managed populations of chimpanzees.