Gentrification drives patterns of alpha and beta diversity in cities.

While there is increasing recognition that social processes in cities like gentrification have ecological consequences, we lack nuanced understanding of the ways gentrification affects urban biodiversity. We analyzed a large camera trap dataset of mammals (>500 g) to evaluate how gentrification impacts species richness and community composition across 23 US cities. After controlling for the negative effect of impervious cover, gentrified parts of cities had the highest mammal species richness. Change in community composition was associated with gentrification in a few cities, which were mostly located along the West Coast. At the species level, roughly half (11 of 21 mammals) had higher occupancy in gentrified parts of a city, especially when impervious cover was low. Our results indicate that the impacts of gentrification extend to nonhuman animals, which provides further evidence that some aspects of nature in cities, such as wildlife, are chronically inaccessible to marginalized human populations.

Urbanization, climate and species traits shape mammal communities from local to continental scales.

Human-driven environmental changes shape ecological communities from local to global scales. Within cities, landscape-scale patterns and processes and species characteristics generally drive local-scale wildlife diversity. However, cities differ in their structure, species pools, geographies and histories, calling into question the extent to which these drivers of wildlife diversity are predictive at continental scales. In partnership with the Urban Wildlife Information Network, we used occurrence data from 725 sites located across 20 North American cities and a multi-city, multi-species occupancy modelling approach to evaluate the effects of ecoregional characteristics and mammal species traits on the urbanization-diversity relationship. Among 37 native terrestrial mammal species, regional environmental characteristics and species traits influenced within-city effects of urbanization on species occupancy and community composition. Species occupancy and diversity were most negatively related to urbanization in the warmer, less vegetated cities. Additionally, larger-bodied species were most negatively impacted by urbanization across North America. Our results suggest that shifting climate conditions could worsen the effects of urbanization on native wildlife communities, such that conservation strategies should seek to mitigate the combined effects of a warming and urbanizing world.

Effects of Complex Feeding Enrichment on the Behavior of Captive Malayan Sun Bears (Helarctos malayanus).

All zoos grapple with challenges of keeping captive animals engaged in natural behaviors, especially for bears which prove to be among the more challenging species to keep stimulated. In captivity, a common indicator of poor welfare is the presence of stereotypic behaviors. This study tests whether providing complex feeding enrichment devices decreases the duration of stereotypic behavior and increases enrichment interaction for three adult female sun bears (Helarctos malayanus) at Oakland Zoo in California. This study uses two different enrichment devices presented at three complexity levels. After three weeks of baseline data collection when no complex enrichment is present, the complex enrichment is introduced three times a week per level over six weeks. Sun bear interaction with the enrichment devices is also measured to examine the effect of complexity on enrichment use. Providing complex enrichment decreased the duration of stereotypic behavior when compared to baseline. Across the six weeks, the duration of stereotypic behavior is significantly less on the complex enrichment days compared to non-complex enrichment days. The complex enrichment has variable effects on enrichment use. These results suggest that providing complex enrichment may have a positive influence on the behavior of captive bears.

The utility of social network analysis for informing zoo management: Changing network dynamics of a group of captive hamadryas baboons (Papio hamadryas) following an introduction of two young males.

Comprehensive knowledge of social groups within zoos allows for better understanding of the issues surrounding group stability and how to provide captive animals with optimal care. A developing area of sociality research that works to improve this understanding is social network analysis (SNA), which allows scientists to apply quantitative measures of group systems to represent social structure. In December 2015, Oakland Zoo introduced two new males to the hamadryas baboon (Papio hamadryas) exhibit. We examined the changing group structure of these baboons over the course of 6 months (July-December 2016) using social network analysis, specifically focusing on the changing social structure of the existing group and the utility of SNA methods for optimal care of captive animals. This study found that over time, the new males decreased their overall individual centrality, while some individuals had an increase in betweenness, a measure of an individual's intermediary role in the network. The results also illustrate the utility of social network analysis as tool for zoo management to examine how husbandry may have an impact on their animals, specifically for social species. Further research on the social networks of hamadryas baboon multi-clan formation could provide more information about the societal structure of this primate species, as well as the use of social network analysis as a valuable tool in captive animal management.

Efficacy of 3 types of foraging enrichment for rhesus macaques (Macaca mulatta).

Primate facilities provide environmental enrichment to improve animal wellbeing, increase opportunities for expression of species-typical behaviors, and decrease the occurrence of stereotypic behaviors. The current study assessed the efficacy of 3 types of foraging enrichment: puzzle balls, supertubes, and shakers. We assigned 48 rhesus macaques to 3 experimental groups, each of which received (after a 3-wk baseline observation period) 1 of the 3 enrichment devices intermittently for 3 wk. Observations were collected during 10-min sessions by using 1-0 sampling with 15-s intervals (480 h total). Observations were collected at the same 10 specified time points each week during the baseline period and after enrichment. Data were analyzed by using generalized linear mixed-effects modeling under the assumption that the underlying response followed a Poisson distribution. Foraging behavior increased significantly in all 3 groups and remained increased in some groups when enrichment was removed after 43 h. The 3 enrichment devices had different effects on individual expression of stereotypy: supertubes decreased it, shakers increased it, and puzzle balls led to a decrease followed by an increase. We present potential reasons for the changes in stereotypy and postulate a likely balance between the beneficial and negative effects of enrichment in any given environment.