Tree kangaroos have experienced a “glow-up” (not a scientific term) over the last five years through science-driven adjustments to husbandry practices in AZA zoos.
These changes, informed by collaborative research led by your Zoo and rolled out by the tree kangaroo SSP, led to improved health and reproduction outcomes in the population and represent meaningful progress for the species. What’s more, the work included a connection to tree kangaroo conservation and is deepening scientists’ knowledge of wild tree kangaroos.
When female Matschie’s tree kangaroo Sausi arrived at Cleveland Metroparks Zoo in 2017, the animal care team noted that she was overweight and not cycling normally. The tree kangaroo SSP (Species Survival Plan), which works across AZA zoos to maintain a healthy, genetically diverse population of tree kangaroos in human care, recommended hormone monitoring to better understand Sausi’s issues and explore population-wide reproduction issues.
Cleveland Metroparks Zoo Research Curator and Tree Kangaroo SSP Research Advisor Dr. Diana Koester implemented the hormone monitoring initiative, finding a dearth of hormonal data for the tree kangaroo population. What began at Cleveland Metroparks Zoo grew into an SSP-wide effort, with your Zoo serving as the endocrine lab for the entire SSP tree kangaroo population. Finding that many females were overweight led the team to investigate diet in conjunction with hormones, looking at energy expenditure, standard calorie recommendations and macronutrient content.
The diet aspect of the study utilized first-of-its-kind data for tree kangaroos, gathered through teamwork between SSP zoos’ animal care and science teams. The Cleveland team trained the tree kangaroos for voluntary blood draws to make data collection easier and less stressful for both animals and staff; this was the first instance of this training in tree kangaroos. Other zoos have since implemented the training. In addition to zoo data, the SSP partnered with the Tree Kangaroo Conservation Program to include data from wild tree kangaroos for comparison. SSP nutritionist Dr. Ellen Dierenfeld led the analysis of diet data and the team used its learnings to create new recommendations, which were rolled out across SSP zoos in January.
The primary takeaways? Tree kangaroos in human care are eating too many calories, and too much grain. The majority of SSP zoos have made changes to how they feed tree kangaroos, seeing browse as a staple rather than an enrichment item and reducing total caloric intake.
Dr. Koester now provides individualized diet and breeding recommendations for tree kangaroos in other zoos based on the research and the animal’s specific issues. The SSP is already seeing positive health outcomes across the population: healthy weights, better skin and fur, improved joint health, and higher rates of reproductive success. She cites your Zoo’s female tree kangaroo as both a cautionary tale and a success story – Sausi arrived obese and lacking a normal cycle, and through research-driven care she achieved a significant health transformation.
The tree kangaroo SSP team is not slowing down with research. In tandem with tree kangaroo SAFE, the AZA program focused on supporting tree kangaroo conservation, they are now exploring the tree kangaroo microbiome. Using fecal samples and diet information from SSP animals along with wild tree kangaroos, the teams hope to gain insights into wild tree kangaroo populations and continue improving tree kangaroo care in zoos.
It is impressive to see what is possible when zoo scientists and animal care experts work together, and in the case of tree kangaroo health, your Zoo’s scientific leadership and collaborative spirit stand out as a point of pride.