The Southern Cricket Frog (Acris gryllus)- the Enigmatic Decline Continues?

Hi, I’m Anikó Tóth, and I’m working in Dr. Micancin’s lab this summer on a project involving amphibian decline. Enigmatic amphibian decline is a phenomenon that is observed around the world, and it refers to the loss of species in habitats that are undisturbed or suitable for their survival.  Most of the public attention surrounding this problem has been focused around the decline of charismatic frog species in exotic locations.  The declines of common species in the United States have not received as much attention, even though, from a biological perspective, the declines of common species are just as, if not more, worrisome.

Our project this summer focuses on the Southern Cricket frog (Acris gryllus).  In the lab this semester, we have been using large collections of museum specimens to identify the historical ranges of the Northern (Acris crepitans) and Southern cricket frogs.  Though the morphological similarities between the two species make them difficult to tell apart, a formula developed by Micancin and Mette (2009) gives a relatively reliable identification based on morphological measurements.  We used the formula to re-identify all the museum specimens, then labeled the  collection sites of each specimen on a map using Google Earth.  Recent investigations have indicated that the Southern Cricket frog may have been disappearing from the northern part of its historical range.  At the same time, the Northern Cricket frog populations in the area have remained stable.  We are using the unique situation–the similarities between the two species and the possible decline of just one of them–to investigate this decline.

This summer our main objective is to confirm the ranges of the Northern and Southern cricket frogs, which used to overlap in a large area in Southern Virginia and North Carolina. We will re-visit the collection sites where specimens were historically collected, find the frogs, and identify them.  In the coming year, we will use the results of our population survey and multiple data layers in GIS to investigate the possible reasons for the decline of these common frogs.  If necessary, we will take steps to list the Southern Cricket frog as threatened in Virginia.  We hope that our results will eventually yield information that can be widely applied to amphibian declines worldwide.

So there you have it, a mini-summary of my project.  I’m so used to writing formal proposals about it that I still sound like a machine.  Sometime within the next few weeks I’m going out to buy myself a strong headlamp and a pair of hip waders.  Most of this work will be nighttime work, as the frogs are shy in the daytime.  It’s very important that we get started as soon as possible, because the easiest way to find the frogs are to catch them when they are calling, which is right now, during their mating season. So I’m gearing up to stay up until three each night and sleep in till noon each day as soon as exams are over!

Thanks for reading! Wish me luck 🙂