Phytotelm Breeding Frogs of the World

After over two years of research and compiling information, I am happy to say that my new website “Phytotelm Breeding Frogs of the World” has launched! Phytotelm breeding frogs are those that reproduce in plant-held water bodies like tree holes, leaf axils or the tanks of bromeliads. Currently, I am aware of 256 frog species distributed in eleven families that breed in phytotelmata (approximately three percent of all known frogs). These species are all tropical or subtropical and often have derived parental care behaviors and bizarre adaptations to life in these micro-aquatic habitats. The distribution of these specialized forms in so many different families indicates that this lifestyle has evolved independently many different times. Much remains to be learned about their lives.

Check it out to learn more!

Phytotelm breeding frogs of the world website
Phytotelm breeding frogs of the world website

New Paper on Polymorphic Squirrels

Just a few days ago, our first paper on melanistic gray squirrels appeared in the journal Ecology and Evolution. This paper was ten years in the making, as the first squirrel surveys in this effort were conducted way back in 2010. Using citizen science data, we found that melanistic gray squirrels (Sciurus carolinensis) are widespread but often localized in the Great Lakes region of the U.S. and Canada. Below is a snapshot of some of the coloration patterns we found in this widespread species.

Figure 1 from Lehtinen et al. 2020

We also found that in Ohio, the frequency of the gray versus the black color morph varies dramatically among locations. In the Wooster, Ohio population (in which monitoring began in 2010 and continues to today) significant changes in color morph frequency over time and space were also detected. However, these changes over space and time in the frequency of our black squirrels seem very idiosyncratic and difficult to predict. We suggest that genetic drift may be an important evolutionary mechanism behind these changes. Many thanks to Brian Carlson, Alyssa Hamm (’20), Lexi Riley (’21), Maria Mullen (’18) and Weston Gray (’19) for all of their contributions to this work!

The full text of the paper can be found here.

Island life, Tobago style

I sit here in mid-December with the thermometer holding steady at 19 degrees F (-7 degrees C) and all the frogs, snakes, salamanders and lizards in Ohio are down for a long winter’s nap. Only a few weeks ago, however, I was studying the Tobago glass frog down in Trinidad and Tobago where it never got below 77 F (25 degrees C) and the snakes, lizards and frogs were seemingly crawling and jumping everywhere (sorry, no salamanders in T&T).

The focus of my trip was this fellow, the Tobago glass frog (Hyalinobatrachium orientale tobagoense).

Tobago glass frog

This species is common on the island of Tobago and was breeding extensively during my November visit. Which was a good thing because mating choices were what I had come to study. Usually, assessing reproductive success in amphibians is difficult because the eggs are extremely well hidden (both from predators and scientists). The Tobago glass frog, however, lays eggs on the undersides of leaves above streams, where the fathers guard usually them until they hatch. So, just by looking to see how many egg clutches a male has, you can tell how much mating success he has had. By comparing lots of males and their reproductive success over time, one can determine what traits females select mates based on.

Or that is the hope anyway. I’m just now entering the data into my computer as the snowflakes fly out the window and I wistfully remember the feeling of warmth.

Dart Frogs Making a Home in Wooster

Thanks to Dr. Cori Richards-Zawacki at the University of Pittsburgh and the hard work of Mackenzie Goltz (’20), we now have a dart frog colony at the College of Wooster! These little beauties are originally from Panama and are brightly colored and day-active. Of course, we don’t have rainforests in Ohio so the tropical room in our greenhouse in Williams Hall is their new home. Each tank has a bromeliad for them to use for shelter and breeding and the males are already starting to call. Hopefully, this is the beginning of a long and productive residency in Wooster!

One of our Oophaga pumilio dart frogs on a bromeliad.
One of our Oophaga pumilio dart frogs on a bromeliad.

Snakes at the Lake

I’ve done a variety of things in my life for a job. Fast food employee, warehouse worker, grocery store shelf-stocker, golf caddy, corn detasseler. And, this past week, I pursued gainful employment as a snake catcher. On the islands out in Lake Erie (of which there are a dozen or more, ranging from very small to moderately large), there are garter snakes. This is the same innocuous and handsome species that occurs throughout much of North America, the eastern garter snake (Thamnophis sirtalis). The especially interesting thing about the Lake Erie garter snakes is that there is a color variant in many areas in and around the lake that is all black (melanistic, see photo).

Melanistic eastern garter snake.
Melanistic eastern garter snake.

Riley Moreau (’20) and I were catching these garter snakes to get DNA samples so we could work in the lab this fall to assess genetic differences among the color morphs, islands and other quantities that one can estimate with modern genetic tools. We found garter snakes on all islands we visited but one. On Middle Bass Island, we had spent about five hours searching with only one snake to show for it and then in the last ten minutes before our ferry departed we caught five more. When it rains, it pours.