Calling all naturalists: We’re surveying salamander stripes!
Do you know what’s the most abundant terrestrial vertebrate in some areas of the United States? It’s not a species of mammal or bird, but an amphibian! The Eastersn Red-backed Salamander is only a few inches long, but in some parts of its range its biomass outweighs that of white tailed deer. Despite how abundant they are, you’ve probably never seen one before as they live under rocks, logs, and in the soil of eastern deciduous forests. An interesting feature of this abundant salamander is its variation in color. When a plant or animal displays two or more color patterns (or morphs) this is known as color polymorphism. The Eastern Red-backed Salamander displays two color patterns, which are known as the “striped morph” and the “unstriped morph”. The striped morph has a red stripe running down the center of it’s black back, and the unstriped morph is uniformly black.
Striped (left) and unstriped (right) morphs of the Eastern Red-backed Salamander.
Because of their abundance, the Eastern Red-backed Salamander is a well studied animal among biologists. Many individuals have been collected and deposited into museums over the last century, and thus, these collections provide an ideal opportunity for biologists to ask a series of questions on the evolution of this salamander. However, research is currently limited by the fact that the morph color was not indicated when salamanders were deposited into collections.
So that is where we need your help! First of all, this new expedition is not as simple as looking for a red stripe. When you preserve a salamander in alcohol for 50 years, which is how they are usually stored in museum collections, the once vibrant color disappears. However, the stripe doesn’t fade to black, it fades a lighter shade of pale. So we are hoping you can help us find the striped morphs and sort them from the unstriped morphs. The crazy thing is that it isn’t like there are a few hundred or thousand of these Plethodon specimens in Museums. One collector who deposited his collections in the Smithsonian actually collected nearly 100,000 salamanders. We may not get around to photographing all of those, but your help with this batch both helps us move the science forward and it helps us with potentially developing machine learning approaches so that we can eventually automate stripe detection.
With help from amazing citizen scientists, once we have color morph information from photographs, we can then use this data to ask unanswered biological questions. For example, we can see if the frequency of the color morphs has changed over time and if they do, we can test if there’s a relationship between the change in color morph frequency with changing climate. In addition, we can see if there’s a relationship between a particular color morph with particular ecological setting. Ultimately, this information will contribute to our growing knowledge of the relationship between color variation and diversity.
For more information on the Eastern Red-backed Salamander, we suggest you check out AmphibiaWeb: https://bit.ly/32q5F6L
Another blog post on the Eastern Red-backed Salamander by an amazing undergraduate student (Kyle Brooks) that previously worked with the author and also contributed photos for this post and the Notes for Nature project. Thanks, Klye!
And finally, another project we could use your help with: