The Effects of Construction and New Habitats on Behavior in Guereza Colobus, Black-Handed Spider Monkeys, and Coquerel’s Sifaka at the Saint Louis Zoo

Zoo habitats are now designed with a larger focus on animal wellbeing and the opportunities provided by more naturalistic environments. While such spaces are assumed to be beneficial for animal wellbeing, evidence to support that assumption is infrequently collected. Our primary objective was to evaluate changes in behavior for three primate species at the Saint Louis Zoo after they were moved from static, indoor habitats to larger, more dynamic outdoor ones. We also used this as an opportunity to document the effects of long-term nearby construction. We quantified behavior for the Zoo’s Guereza colobus (Colobus guereza), black-handed spider monkeys (Ateles geoffreyi), and Coquerel’s sifaka (Propithecus coquereli) indoors prior to construction (i.e., baseline), during the construction period, and after the animals moved to new outdoor habitats. In addition, sound data were collected during the baseline and construction phases of the study to quantify the potential effects of noise on behavior. Linear models were used to test differences in behavior between phases and associations of behavior with logarithmic daily average median sound levels while controlling for covariates such as group size and gate count. We observed evidence that construction may have been aversive, such as an increase in time spent inactive, a decrease in time spent locomoting, and an increase in self-directed behaviors. However, most models explained minimal variation in these behaviors, suggesting construction had a relatively weak impact on behavior. The differences observed between the baseline and new habitats phases indicated the new habitats were beneficial for animal wellbeing, including increases in some positive species-typical behaviors, decreases in agonistic behavior in the colobus and sifaka, and decreases in self-directed behaviors in the colobus and spider monkeys. This study provides evidence that large, dynamic, naturalistic habitats have beneficial effects on primate wellbeing, as measured using a combination of species-typical and self-directed behaviors.