1. La Kretz Center for California Conservation Science, Institute of the Environment and Sustainability, University of California, Los Angeles, California 90095

2. Institute of Zoology, Zoological Society of London, Regents Park, London NW1 4RW, United Kingdom

3. Institute of Infection, Veterinary and Ecological Sciences, Biosciences Building, University of Liverpool, Crown Street, Liverpool L69 7ZB, United Kingdom