Acoustic Communication in Treefrogs
My dissertation research is concerned with the evolution of sexual signaling in anuran amphibians. During their breeding season, male frogs and toads gather in dense breeding aggregations and produce advertisement calls. Females use these vocalizations to discriminate among potential mates and thereby exert selective pressure on males and their signals. I use phonotaxis (movement toward sound) behavior to study mate choice and the evolution of sexual signals. This slideshow contains images taken during my field collections of treefrogs from breeding ponds at night.
Evolution of Sexual Signaling in Crickets
Teleogryllus oceanicus, the Pacific field cricket, was introduced on Hawaii, where it co-occurs with a parasitoid fly, Ormia ochracea. Gravid female flies locate calling male crickets by their song and deposit larvae on them. Fly larvae develop inside the cricket, eating his organs and finally killing him when they emerge to pupate. This natural selection disfavors calling by male crickets, but song is strongly favored by sexual selection, because acoustic signals are the only long-range means of advertisement. I'm interested in the evolution of mating behavior in this system, where natural selection and sexual selection work in opposing directions.
Effect of UAV Presence on American Black Bears
Unmanned aerial vehicles (UAVs, aka "drones") are increasingly popular tools for wildlife biologists to monitor populations. However, drones are more maneuverable than other aircraft, and not subject to the same altitude limitations imposed by law. The following photos were taken during field work investigating the effects of UAV noise on American black bears with colleagues at the University of Minnesota, including Dr. Mark Ditmer, Dr. John Vincent, and Leland Werden.
This work by Jessie C. Tanner is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.