Funding for this research was provided by:
National Park Service (Cooperative Agreement P12AC30548)
Received: 16 August 2019
Accepted: 15 October 2019
First Online: 28 November 2019
: Our research plan (#PMB-87-3095) was reviewed and approved in advance by the Institutional Review Board of the Uniformed Services University of the Health Sciences.
: All of the images in this article were taken by the author, who grants permission for them to be published. There are no identifiable images included in this manuscript.
: The author declares that she has no competing interests.