Estimating contact rates of Eastern newts (Notophthalmus viridescens) at differing temperatures, densities and habitat structure
Peterson, A. C., M. Bohanon, E. D. Carter, B. A. Bajo, P. Watcharaanantapong, D. L. Miller, J. G. Surles, and M. J. Gray.  2020.  9th World Congress of Herpetology, Otago, Dunedin, New Zealand.  (invited)

Abstract:
The recently discovered pathogen Batrachochytrium salamandrivorans (Bsal) is responsible for driving ongoing declines in salamander populations in Europe. While this pathogen has not yet been detected in North America, the introduction of Bsal into novel regions is likely. Transmission of Bsal can occur via direct contact, thus a key component in understanding the ecology of this pathogen is to identify how contact rates in host species vary across realistic conditions. Such work can inform management strategies that may help limit Bsal spread when introduced into novel populations. In this study, we placed adult Eastern newts (Notophthalmus viridescens), a widespread North American salamander species known to be susceptible to the Bsal pathogen, into 1-m2 aquatic trough enclosures at varying densities (2, 4, 8 and 16 animals/m2). We also experimentally manipulated habitat structure (0, 4, 8, 16 plants/m2) and water depth (3, 6, 9, 12) using a Latin-Square design. We utilized video recording of animals from eight diel periods to estimate how daily contact rates vary across these conditions at three biologically relevant temperatures (6C, 14C and 22C). The results of this experiment can be used to parameterize models of Bsal transmission, and can facilitate identification of potential management strategies (such as altering host density, habitat structure, water depth or temperature) to limit Bsal spread if introduced into North American salamander populations.