Wild Ideas: The joys of frog monitoring

Frog info online

Frogwatch USA: www.aza.org/frogwatch

Audio files of frogs native to Virginia: Virginia Herpetological Society, www.virginiaherpetologicalsociety.com

Breeding schedule for Virginia frogs: Virginia Department of Game and Inland Fisheries, www.dgif.virginia.gov/wildlife/frogsurvey/vftswherewhen.pdf, or go to the home page and search on “start calling”

In my youth, the calls of the early-breeding frogs, along with blobs of gelatinous eggs in pools and puddles, had marked the start of spring and put me into a frog-hunting frenzy.

There are three ponds here where I live (two at the base of the mountain and one near the summit, above my house), along with some manmade tanks that are fed by spring and rain water. The two lower ponds have fish in them, but the tanks and upper pond seem free of them. Not having fish around is a good thing for frogs, who are often preyed upon by them. In fact, Wood Frogs, the earliest breeders, will only lay their eggs in fish-free vernal pools.

I hadn’t heard Wood Frogs or Spring Peepers calling this year and was afraid I wouldn’t see any frogs until the Green Frogs came later. I’d heard them last year after I moved in in June, so I was sure they’d be back.

Then, in this third week in March, I found amphibian egg masses along the edges in the upper of the two ponds at the base of the mountain and in a nearby drainage ditch. It’s amazing to think such large egg masses can come out of such small amphibians but, after being laid, amphibian eggs immediately take on water and swell.

Most amphibians tend to lay their eggs in shallow areas, often attached to vegetation or dead wood to anchor them, to keep them out of the reach of predatory fish, which are abundant in these lower ponds. When the tadpoles hatch out, they are also likely to stick close to shore for the same reason. However, River Otters, Raccoons and some water turtles abound down there, so the survival rate of eggs and tadpoles is likely low, as it is pretty much everywhere.

While I was checking out the eggs in the pond, I heard the slow, sustained, rasping call of a Pickerel Frog (Lithobates palustris) – like a long burp – so I surmised that the egg masses probably came from this species, which normally breeds this time of year. Although Red-spotted Newts have been engaged in amplexus (sort of a mating hug common to amphibians, which can go on a long time, with or without actual egg production) for at least a couple of weeks, only one mass looked like it may have been produced by them.

A Pickerel Frog, common to Virginia. They’re now breeding here in the Blue Ridge.
Sam Hopewell via Wikimedia Commons
A Pickerel Frog, common to Virginia. They’re now breeding here in the Blue Ridge.

I’d been considering getting involved in the Frogwatch USA monitoring again, something I’d abandoned when I moved to the last house, which was on a dry ridge that lacked breeding habitat, but I’d been slow to sign up at the new house because of the lack of frog calling on the property. Hearing the Pickerel and seeing the egg masses spurred me on, so I registered this site with Frogwatch as soon as I got back to the house.

Waiting until a half hour after dark that evening, as required by the Frogwatch protocol, I went down to do my first official monitoring session at the ponds. The protocol calls for waiting a few minutes before starting the actual monitoring, so the frogs can get used a human presence and be in full voice. I could already hear Pickerels calling but sat down and patiently waited before starting the three-minute session.

Under the protocol, all I have to do is give a gross estimate of the number of frogs calling for any species I heard, on a scale of 0 to 3. In this case, I chose 2 (“calls of individuals could be distinguished, some overlapping of calls”). Just as I was finishing up my monitoring segment, I heard the lone call of a Spring Peeper close enough to add it.

It’s great to just sit and listen to the calls, but what I really wanted to do was see the frogs, so I took my flashlight and slowly moved to the pond edge, got down on my knees, turned the light off and waited. Once the sounds returned and I’d figured out where they were coming from, I turned on the flashlight and carefully inspected the area. Although I could hear the frogs and knew what Pickerels looked like, they were still well camouflaged within the vegetation close to the bank.

Pickerels spend most of their lives on land at the edge of ponds or pools, jumping in to avoid predators, but as with most frogs that mate in water, they were half-submerged as they called. Along with the typical rasping call, there were some clucks similar to Leopard Frogs, which have similar coloring. However, Leopards don’t have the long, rasping calls and are also more common to lowland areas to the east of the county.

Frogwatch is a great monitoring program for us lazy folks. The monitoring sessions are short and easy, since there are only a few species of frogs whose calls that have to be learned, and the calls are distinct from each other. I used to just carry my MP3 player with the calls on it when I first started monitoring a few years ago and digitally recorded calls when I was unsure so I could review them later. In the dead of winter, I sometimes play back those sessions to remind me that spring will eventually come and to return to those peaceful moments on a spring or summer night.

A mass of amphibian eggs, probably of a Pickerel Frog.
Pam Owen | Rappahannock News
A mass of amphibian eggs, probably of a Pickerel Frog.

Frogwatch volunteers set their own schedules for how often to monitor, although we’re encouraged to monitor at least twice a week during the breeding season, which can run here from February for Wood Frogs (sometimes even January) until October, when the last Bullfrog and tree frog have gone silent. While it used to be possible to fill in data forms online, now the forms have to be filled in and returned by e-mail (preferred by AZA) or by regular mail. Altogether, Frogwatch is about as easy as wildlife monitoring gets, and should be even easier where I live now, considering the site is next to the driveway and there’s already a nice, comfortable chair by one of the ponds.

One of the best things about monitoring is that it requires quiet communion with nature for at least a few minutes out of what can be a hectic day. And there’s no reason not to linger there at the site and stretch out that experience after the monitoring session – maybe with a cold beer or glass of wine. I also use the time to explore around the pond to see who else is active down there.

Frogwatch is also a great way to get kids involved with nature. My sessions remind me of some of the happiest moments in my childhood and how much I still enjoy being so close to nature. I feel lucky to be able to witness events that have kept the cycle of life going for millennia.

Pam Owen
About Pam Owen 338 Articles
Writer, editor, photographer, and passionate nature conservationist living in Rappahannock County, in the Blue Ridge Mountains of Virginia. Two favorite quotes: By E.O. Wilson, who coined the term "biodiversity," "Nature holds the key to our aesthetic, intellectual, cognitive and even spiritual satisfaction”; by Douglas Adams, “I love deadlines. I love the whooshing sound they make as they pass by.”