The Detroit Zoological Society's (DZS) Center for Zoo Animal Welfare (CZAW) was created to advance the science and policy of the welfare of exotic nonhuman animals in captivity. This important part of the DZS mission is achieved through assessments of, and research on, the welfare of animals in zoos; by recognizing extraordinary achievement in the advancement of animal welfare; by widely sharing knowledge through a bibliographic resource center; by conducting professional training for animal care staff; and by convening important discussions in the form of international symposia. This special issue of the Journal of Applied Animal Welfare Science features selected papers from the most recent international CZAW symposium held at the Detroit Zoo in November 2014, as well as a universal framework for zoo animal welfare developed by the DZS.

Many animals have been tested for conceptual discriminations using two-dimensional images as stimuli, and many of these species appear to transfer knowledge from 2D images to analogous real life objects. We tested an American black bear for picture-object recognition using a two alternative forced choice task. She was presented with four unique sets of objects and corresponding pictures. The bear showed generalization from both objects to pictures and pictures to objects; however, her transfer was superior when transferring from real objects to pictures, suggesting that bears can recognize visual features from real objects within photographic images during discriminations.

Although historically understudied, the empirical evaluation of captive reptile welfare is becoming more common, and zoos continue making modifications to their reptile facilities with the goal of improving welfare. In this study, we evaluated the impacts of habitat modifications on the behavior of five Madagascar giant hognose snakes (Leioheterodon madagascariensis) housed in the Holden Reptile Conservation Center at the Detroit Zoo. The snakes' enclosures were modified from smaller stainless steel boxes with newspaper substrate and plastic hide boxes to larger enclosures with open glass fronts and naturalistic elements. Along with nearly doubling enclosure size, the new enclosures featured a deep sand/mulch mixture for substrate instead of newspaper, as well as corkbark furnishings in addition to the plastic hide boxes. We hypothesized that the modifications made to the enclosures would provide opportunities for the expression of species-typical behaviors, such as exploration, digging (an important foraging behavior for hognose species), and locomotion, as well as increased behavioral diversity and overall activity levels. Each individual was observed for a total of 7.7 hrs with approximately 3.8 hrs in both the baseline and modified conditions. Data were collected using both scan and all-occurrence sampling methods in 10min focal observation sessions, twice daily, three times a week. Generalized linear mixed models showed that the modified habitats increased behavioral diversity and environmental exploration compared to baseline data. One snake showed substantially different behavioral trends due to a unique medical condition, highlighting the need to consider individual differences when evaluating snake welfare. These results support our hypothesis and provide evidence that habitat modifications informed by ecology and natural history are successful in promoting speciestypical behaviors as indicators of positive welfare in snakes.

Reintroduction programs in which captive-bred or reared animals are released into natural habitats are considered a key approach for conservation; however, success rates have generally been low. Accounting for factors that enable individual animals to have a greater chance of survival can not only improve overall conservation outcomes but can also impact the welfare of the individual animals involved. One such factor may be individual personality, and personality research is a growing field. We designed a project to ascertain the presence of personality traits in Blanding’s turtles (Emydoidea blandingii), a species of special concern in the state of Michigan, and to assess potential links between traits and post-release success. As hypothesized, the Blanding’s turtles in this study displayed behavioral responses to modified open field tests indicative of distinct personality traits: exploration, boldness, and aggression. Additionally, the personality traits were correlated differently with survival and behavior patterns when the turtles were released into the Shiawassee National Wildlife Refuge. More exploratory turtles had higher survival rates, while neither boldness nor aggression was related to survival. Exploratory turtles were also more likely to travel longer distances after release. The use of muskrat dens was related to increased survival, and both bolder and more exploratory turtles made higher use of this feature. Exploratory and aggressive turtles were found basking outside of water more often, while bold turtles were more likely to be found at the water surface. Both these basking behaviors may increase the risk of predation and may be reflective of a trade-off between the risk and behaviors related to physiological health. Understanding how personality affects behavior and survival post-release can be a critical tool for improving reintroduction success. Zoo animal welfare scientists and practitioners can implement approaches that improve the welfare of individuals within the context of conservation initiatives.

We investigated how forage material affects indicators of welfare in three male Western lowland gorillas (Gorilla gorilla gorilla) at the Detroit Zoo. In addition to their maintenance diet and enrichment foods, the gorillas generally received forage material four times a week. From this baseline, we systematically manipulated how much forage material the group received on a weekly basis, with either daily or bi (twice)-weekly presentation of browse (mulberry, Morus sp.) or alfalfa hay. We collected behavioral data (60 hr per gorilla) and measured fecal glucocorticoid metabolites (FGM). Mixed models indicated that the presence of forage material significantly increased time feeding (F = 9.58, p < 0.001), and decreased rates of noncontact aggression (F = 3.69, p = 0.03), and regurgitation and reingestion (F = 4.70, p = 0.01). Regurgitation and reingestion were never observed during the condition when forage material was provided daily. When forage material was provided, time spent feeding was similar across gorillas, compared to a disproportionately greater amount of time spent feeding by the dominant individual when forage material was absent. Providing forage material in addition to the regular diet likely created more opportunities for equitable feeding for the subordinate gorillas. FGM concentrations did not vary based on the presence or type of forage material available and, instead, likely reflected group social dynamics. In general, alfalfa and mulberry had similar impacts on behavior, indicating that alfalfa can be an adequate behavioral substitute during times when browse is less readily available for gorillas housed in seasonally variable climates.