The Language of Frogs: FrogWatch USA

I think I've mentioned it here on steemit before, but I am a chapter coordinator for the FrogWatch USA program. FrogWatch USA is almost exactly what it sounds like; it's a nationwide effort to monitor local frog and toad populations to assess health, distribution, and environmental quality. The program is a citizen science initiative, meaning that rather than a study conducted by a few professional individuals in a small area over a small amount of time, the study is conducted by thousands of citizen volunteers which allows for sampling across a much wider range and time scale. Anyone can join FrogWatch USA regardless of amphibian knowledge (check out the page here!).

Why study frogs with such an intensive program? Frogs are living biological health barometers, and are a crucial means for monitoring the health of the ecosystem. Amphibians are incredibly sensitive animals and are generally the first to show signs of declining environmental health (they are often compared to "canaries in the coal mine"). The frogs are essentially an early warning system; if the frog populations begin declining or disappearing completely, it's generally a sign to biologists that things are about to go downhill fast. By monitoring these populations, scientists can monitor these early symptoms of ecological collapse, and begin taking steps to treating the problem. The data uploaded by the volunteers of the FrogWatch USA program is openly available to anyone; many research groups utilize this data in wildlife management and urban development studies.

The name FrogWatch USA is somewhat misleading...we don't actually watch or even look for frogs; we listen. Volunteers are trained to identify their local frogs and toads simply by listening to their breeding calls. I can say with pride that I can identify a little over 50 species of frogs and toads just by their calls alone! Monitoring is quite simple, we just listen for a duration of exactly 3 minutes and record what species we can hear and at what intensity. 3 minutes per volunteer is all it takes to create a massive data set for the entire country (this is why citizen science is becoming so valuable to scientists; when everyone pitches in a little effort, the results are astounding!).

Being a FrogWatch USA volunteer means understanding the basics of frog communication. The following are the different types of calls we hear when were are in the field.

Breeding (Advertisement) Calls are what we record and monitor because EVERY species has a unique sound. This is because the frogs are calling out for a mate, and they have to stand apart from all the other species calling out there. This is the best way to identify frogs and toads; many species that are almost identical in appearance can be easily distinguished by their unique call. Some of these calls do sound very similar to our ears, but vary just ever so slightly in pitch or tone quality from one another. The only downside to breeding calls is that they will only be heard during the breeding season (obviously). This means that we may observe species of frogs in the field, but because it is outside their breeding season, they aren't making any calls.

Aggressive (Antagonistic) Calls are grunts or growls (or high pitched shrieks like the video below) that are issued by males; these calls are usually made by males guarding a breeding site as a warning to other males. The antagonistic call isn't of much use to FrogWatch USA monitors because there is little variation among the calls made by different species. This call is pretty universal for "back off". 

This Desert Rain Frog is adorable but REALLY angry!

A Release Call is often made when a frog or toad is picked up, either by a predator or human. It is a sharp chirp or cluck-like sound meant to startle their captor into releasing them, and is often accompanied by body vibrations. This call is not recorded because, like the aggressive calls, there is little variation between species of frogs (and we don't generally hear release calls since we are not catching frogs).

You have probably heard an Alarm Call yourself. While walking along the waters edge, frogs  will jump into the water as you approach making a high pitched squeaking sound. The sound is meant to distract predators while also issuing a warning to frogs in the surrounding area of the impending danger. Like the aggressive and release call, there isn't much variation among release calls (these probably sound the most alike between frog species).

Finally, Rain Calls are made generally just before, during and after heavy rain events. The calls are also recorded by FrogWatch Volunteers because the rain call is actually just a weaker version of the breeding call, so they are unique among species. This allows us to record the calls of some frogs and toads even outside their breeding season.

We can learn so much from the songs of frogs and toads, but we always need more volunteers around the US! The FrogWatch USA is a fantastic program that allows ordinary people, even those without any scientific background, a chance to engage in active research. The program is free and requires very little of your time and energy (for our chapter, the biggest commitment is a 4-hour training session; once passed, the program only requires THREE MINUTES of your time once or twice a year). It's a great way to get involved in environmental research or even just identify the native species living in your own backyard; if you're lazy like me, you can even monitor frogs around your home! To learn more about the program, check out the link to the amazing FrogWatch USA intiative!

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Video Links: 1, 2, 3, 4, 5, 6, 7