This is an NSF Postdoctoral Research Fellowship in Biology, under the program Broadening Participation of Groups Under-represented in Biology. The fellow, Talisin Hammond, is conducting research and receiving training that increases the participation of groups underrepresented in biology, at the University of Pittsburgh, and is being mentored by Cori Richards-Zawicki (sponsoring scientist). This research explores how the reproductive behavior and physiology of multiple species of frogs is affected by chytridiomycosis, a fungal disease that has decimated many amphibian populations. In addition to improving our understanding of how this disease impacts amphibians, which are currently highly threatened by numerous environmental factors, this work also clarifies the role of sub-lethal effects of disease on population dynamics and evolutionary processes. As part of this project the fellow is working with a natural history museum to teach student groups about science using sketch-noting. The fellow is also designing a research-based educational module, which will be freely available, and is working with an online network to find educators interested in its implementation. Finally, the fellow is mentoring diverse undergraduate students.
Wildlife diseases impact populations both directly, through mortality, and indirectly, through sub-lethal changes to host biology. Disease-induced fatalities can be devastating, but sub-lethal changes in behavior and physiology also have the potential to exert substantial pressure on populations. The terminal investment hypothesis, which states that animals with decreasing future reproductive potential should invest more in immediate reproduction, predicts that sick animals with decreased longevity should elevate reproductive effort, and that species with higher susceptibility should increase effort more. The fellow's research is testing this hypothesis, focusing on chytridiomycosis as the disease agent. The processes by which this disease kills amphibians are better-understood than its sub-lethal impacts, and few studies have experimentally described how chytridiomycosis impacts reproductive behavior and physiology. This project uses three congeneric frog species with differing disease susceptibility, using call recordings, behavioral choice tests, and hormonal manipulations in conjunction with quantifications of pathogen load, immune function and spermatic traits to characterize how the disease affects male reproductive behavior and physiology, and female preference. This work is generating novel insights into the role of sub-lethal, disease-mediated behavioral and physiological effects on individuals. In addition to providing training support for the fellow in a new field of study, this work also involves significant outreach, including teaching student groups visiting natural history museums, developing a research-related, online-available educational module, and mentoring diverse undergraduate students.
