The Benefits of Increased Space and Habitat Complexity for the Welfare of Zoo-Housed King Penguins (Aptenodytes patagonicus)

SIMPLE SUMMARY: Habitat design influences every aspect of welfare for captive animals, including the sensory milieu, opportunities to forage for food, the ability to make choices about where to engage in species-typical behaviors, and the opportunity to regulate proximity to other animals sharing a space. Moving a group of animals from one designed space to another provides an opportunity to observe how their behavior is shaped by habitat design features. In this study, we observed the behavior of ten king penguins as they were transferred back and forth between two habitats at the Detroit Zoo. The Penguinarium, although state of the art for its time, opened in 1968 and offered less space and complexity than the naturalistic, expansive Polk Penguin Conservation Center (PPCC), which opened in 2016. These penguins spent more time swimming when they had access to the substantially larger pool of the PPCC. They also engaged in more positive social behaviors, such as species-typical displays and allopreening, and fewer aggressive behaviors in the PPCC. The results support a positive connection between the design of the PPCC and improved welfare for these king penguins. ABSTRACT: Zoos and aquariums accredited by the Association of Zoos and Aquariums embrace animal welfare as a foundational principle of habitat design. Modern habitats are designed to provide animals with choices and agency over their environment, and to encourage species-appropriate behavior and space use. In 2016, the Detroit Zoological Society opened the Polk Penguin Conservation Center, a 3065.80 m(2) facility that features a naturalistic design. The building was designed to optimize animal welfare by incorporating various substrates, nesting sites, and a 1234 kL pool with elements of underwater complexity. The facility houses a mixed-species group of penguins that were previously housed in a smaller habitat that opened in 1968. Between 2015 and 2022, we opportunistically monitored the behavior of ten king penguins (Aptenodytes patagonicus) as they moved back and forth between the two buildings while additional modifications were made to the new habitat. We collected 695 h of behavioral observations and 10,416 h of data from flipper-mounted time–depth recorders. We found that the king penguins spent less time engaged in aggression and more time engaged in swimming and positive social behaviors in the redesigned space. They also spent less time in proximity to other species of penguins and more time alone. These behavioral trends suggest that increased space and environmental complexity had positive welfare benefits for these penguins.