An acoustic recorder was set up at the Racine Zoo to pick up the tigers’ roars. Anya, one of the zoo’s Amur tigers, is in the background.

RACINE — This past fall, The Prusten Project and the Racine Zoo teamed up to help save wild tigers.

The Prusten Project is an innovative project which combines the fields of conservation biology, bioacoustics, animal behavior, and ecology to study the social vocalizations of tigers. The Racine Zoo’s Amur tigers, Anya and Naka, were recorded as part of the The Prusten Project’s acoustic monitoring research program at the zoo. The Racine Zoo is participating in the second phase of the vocalization research where The Prusten Project hopes to establish a baseline for all of the tiger sub-species vocalizations before moving to the wild in the third phase.

Acoustic recorders were set-up in places near the tiger habitat that allowed them to pick up the tigers’ roars. Each individual tiger was continually recorded day and night over the course of two different three day sessions. Keepers were responsible for moving the recorders inside and outside with the tigers and knowing where the optimal sound pick up would be. This project has given many zookeepers a unique look into the conservation efforts working to save the animals they care for day in and day out in human care. These roars were then analyzed and project researchers were able to distinguish vocal fingerprints for the tigers.

The Prusten Project can determine a tiger’s age, sex, and subspecies based on these roars alone? Determining if tigers do have unique vocalizations based on sex, age, or individual could lead to new methods of remote monitoring. This could allow a more efficient, as well as minimally disruptive, census of critical populations where dense jungle prohibits visual confirmation. A project of this magnitude will be the first of its kind for tropical mammals — specifically large carnivores. The goal is to apply this new identification method to tigers in the wild. This could be a game changer in the way the animals are monitored and protected. It also has the potential to be more accurate when it comes to determining populations than current methods, which include looking for paw prints and using camera traps.

“Now that we can track tigers using their voices alone we can establish better monitoring methods that are less invasive,” said Courtney Dunn, Prusten Project founder. “We can understand populations of tigers better, and can focus anti-poaching efforts where they matter most.”

Poaching continues to threaten tigers even in protected parks and reserves. Acoustic monitoring holds the promise of more efficient protection efforts and decrease in the potential for local crime rates related to poaching rings, as a more accurate census would allow law enforcement to focus on core areas. Furthermore, the recorders can also pick up noises like poachers voices and gunshots.

The Prusten Project is currently set to get bio-accoustic recorders in the wild in 2018 in India and Sumatra. To help with this goal, Racine zookeepers and fellow Milwaukee zookeepers held a pizza dinner and silent auction fundraiser in November for The Prusten Project through their local American Association of Zookeepers Chapter. They were able to raise $1,046 to help purchase more recorders for the project. Each recorder costs approximately $1,000.

“With only 3,000 tigers left worldwide, every little bit we can do to help those that are left in the wild counts,” said Amy Petersen, primary carnivore keeper. “Saving endangered species is why a lot of us became zookeepers.”

To help The Prusten Project as they are set to take their research to the wild, go to


Community Coordinator

Loreen Mohr is the community coordinator for The Journal Times.

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