Falling in Love with the Wyoming Toad

The following is an update from Rachel Santymire, Ph.D., director of the zoo's Davee Center for Epidemiology and Endocrinology, about ongoing conservation field work on behalf of wild amphibian populations imperiled by chytrid fungus, an infectious disease that has devastated amphibian populations worldwide over the past few decades. Santymire recently traveled to Wyoming to support the U.S. Fish and Wildlife Service's efforts to protect one of the state’s native amphibian species.

The American toad, a common species that we can find in our backyards, has always been one of my favorite amphibians. In my yard, I have had several toads that seemed to have their own territories. One lives on my back steps, one lives in my barn, and one lives under the horses’ water trough. I frequently see them there in the summer. I have to say, however, that when I saw my first Wyoming toad, my heart was stolen.

The Wyoming toad is critically endangered and only found in one county—Albany County, Wyoming—in the world. Similar to the black-footed ferret, this toad faced several anthropogenic pressures like water pollution and habitat changes that nearly caused its extinction. The U.S, Fish and Wildlife Service (FWS) rescued the last remaining individuals to start a breeding program in the early 1990s. Now there are five sites in Albany County where they have been reintroduced.

Wild-population scientists have had some recent success with Wyoming toad egg masses being found at some of the sites. But fearing the extinction of the species from the disease called chytridoiomycosis (i.e. the chytrid fungus), FWS has been looking for partners to develop new tools that can be used to monitor the health and success of wild populations. This is where the Davee Center for Epidemiology and Endocrinology expertise is now playing a role in its recovery. We hope to use our innovative “frog swab” methods (we use a scientific q-tip to swab the amphibian’s skin to measure stress hormones) to evaluate the stress physiology of the Wyoming toad both in the reintroduction sites and the breeding program.

Lizzie Mack and Rachel Santymire swab a Wyoming toad at the U.S. Fish and Wildlife Service's Leadville National Fish Hatchery.

In early May, I was out in Leadville, Colorado, at the FWS’s Leadville National Fish Hatchery testing out our frog swabs on their Wyoming toads. These toads were so engaging. They watched me move around the room in hopes that I would feed them some tasty insects (roaches and crickets), which I did get to feed them. See proof below:

Lizzie Mack, from FWS, and I received funding from Memphis Zoo’s Conservation Action Network fund to develop our stress evaluation methods. We have even involved our collaborator, Dr. Allison Sacerdote-Velat, Curator of Herpetology at The Chicago Academy of Sciences at the Peggy Notebaert Nature Museum. Allison will be going to the field, searching for Wyoming toads, and taking swabs for stress analysis and the presence of the chytrid fungus. We hope that our methods will help answer questions about population success of wild and captive Wyoming toads. Results are still pending as we just got samples (including toad poop) from Leadville and will be validating this novel method for another amphibian species.

Rachel Santymire, Ph.D., is director of Lincoln Park Zoo’s Davee Center for Epidemiology and Endocrinology.