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Additional Information

Competing Interests

The authors declare that they have no competing interests.

Author Contributions

Crystal L Egelkamp wrote the paper.

Lydia M Hopper wrote the paper.

Katherine A Cronin reviewed drafts of the paper.

Sarah L Jacobson reviewed drafts of the paper.

Stephen R Ross wrote the paper.

Animal Ethics

The following information was supplied relating to ethical approvals (i.e., approving body and any reference numbers):

This study was approved by the Lincoln Park Zoo Research Committee, which is the governing body for all animal research at the institution.

No approval number is associated with this review.

Data Deposition

The following information was supplied regarding data availability:

The research in this article did not generate, collect or analyse any raw data or code.


This research was funded by the Chauncey and Marion McCormick Foundation, the Leo S. Guthman Fund and Lincoln Park Zoo. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

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