1 Department of Ornithology and Mammalogy, California Academy of Sciences, San Francisco, California, USA.
2 Department of Dermatology, University of California San Francisco, San Francisco, California, USA; Veterans Affairs Health Care System, San Francisco, California, USA.
3 Department of Dermatology, University of California San Francisco, San Francisco, California, USA; Veterans Affairs Health Care System, San Francisco, California, USA. Electronic address: peter.elias@ucsf.edu.
4 Institute for Advanced Study of Mathematical Sciences, Meiji University, Tokyo, Japan.