To imitate this type of feeding, the tree kangaroos at the San Diego Zoo were presented with a similar challenge. They were presented with a new enrichment item, a puzzle feeder, in which their folivore biscuits and browse (the leafy part of an animal’s diet) were hidden. Getting out the food required a much more complex thought process than getting food presented in a specific feeding location. But the tree kangaroos took up the challenge and succeeded! Because the browse was sticking out of the feeder and was visible, they quickly realized that the large gourds (the puzzle feeders) in their exhibit were more than just “decorations.” Soon after investigating the gourds and extracting some of the browse, they realized an even greater treasure to be gained: folivore biscuits!Their investigation of the puzzle feeders quickly advanced from simple sniffing and pulling at browse branches to gripping the feeder holes with one hand and extracting biscuits with another. One of the most impressive methods of investigation involved using the rope that the feeder was suspended by to pull the feeder to them. After pulling the feeder up on the log, they had better access and could more deftly extract their favorite treats.
This enrichment was a learning experience for both the tree kangaroos and me. The tree kangaroos had the opportunity to discover new skills that can be used to acquire desired items that are more difficult to access. I learned that even though this enrichment was challenging, tree kangaroos use trial and error to figure out which behaviors worked and which didn’t to get what they need. In the end, the tree kangaroos were not puzzled at all!
At this point, I’m half way through my data collection, and I’ll check back before I leave to update you on some final results of my marsupial enrichment study. It’s fascinating to me how an animal enrichment study has now enriched my understanding of animals!
Lauren Kline is a Bonner Summer Student Intern in the Behavioral Biology Division at the San Diego Zoo’s Institute for Conservation Research.