Amphibians: Canaries in the environmental coal mine
By Gary Raham
Nature Writer and Illustrator
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"You're going to do what?" a friend of mine asked, smiling--although
he had obviously heard me quite clearly.
"Listen to frogs croak," I repeated, also with a smile. "It's important,
really," I added, but he took some convincing.
Frogs, toads, and other amphibians hopped, crawled and swam through 400
million years worth of travails, only to confront habitat loss and an influx
of designer compounds infiltrating the world's wetlands through human activity.
A fungal disease has also devastated some populations, perhaps already
stressed and vulnerable. Amphibian die-off, like the death of canaries
by noxious gases in coal mines during the last century, may be warning
us of serious environmental dangers ahead.
Amphibian deaths have surprised scientists because most of them, like a
majority of people, don't give frogs, toads and salamanders much thought.
Amphibians tend not to touch our daily lives unless we have a voracious
appetite for frog's legs. They don't attack us, feed us or cuddle up beside
us like warm puppies. They sit on lily pads, snatch flies from the air,
masquerade as princes--and whatever else they do--in relative obscurity.
But because their skins are sensitive conduits for oxygen and other chemicals,
they make excellent barometers of environmental health.
Amphibians and reptiles (collectively known as herpetofauna, or herps,
for short) do have their champions and defenders. Some of those fans work
for the U.S. Geological Survey. Researchers here have set up a standardized
North American Amphibian Monitoring Program.
Frogwatch USA is a partnership program affiliated with USGS and designed
to enlist the aid of volunteers in describing and monitoring herps nationwide.
This year--designated "The year of the frog" by Amphibian Ark, a conservation
organization--the Fort Collins Natural Areas Program is using its cadre
of volunteers to make a baseline survey of amphibians in Fort Collins natural
areas. I am one of about 80 volunteers, many of them families, who offered
to listen to frogs and toads sing, croak and otherwise vocalize to help
discover just what kind and how many occupy the Poudre River corridor.
This will help governments and environmental organizations better manage
lands in their care.
McMurry Natural Area and Magpie Meander Natural Area serve as a nature
corridor between North College Avenue and Shields Street with access near
Hickory Street. Magpie Meander features Wood Duck Pond and McMurry contains
McMurry Pond and Sunfish Pond. Armed with instructions, observation forms,
a thermometer and a CD of amphibian calls, I invaded the herp homeland
and listened while males tried to engage the attention of appropriate females.
During my May date encounter with herps at Wood Duck Pond only the chorus
frogs chirped--a distinctive sound like running a finger over a comb.
Two or perhaps three individuals swapped froggy IDs beneath a nearly full
moon. Overhead, a bat or two swooped low, snatching mosquitoes and other
insects from the air. I met Dale, another amateur frogophile, and even
talked my wife, Sharon, into joining the expedition. We trekked along trails
speckled by moonlight, forced to pay attention to wind speed, temperature,
cloud cover and all the other natural things from which we are normally
insulated, but that dictate the behavior of our subjects.
By June, the chorus frogs had swelled to a small convention, calling continuously.
Sharon and I explored the pond alone, as Dale was out of town. After a
few minutes of silence, two woodhouse toads added their voices, sounding
like crying infants or just a bit like the scream in a grade B horror movie.
A few red-winged blackbirds trilled back and forth as the twilight faded.
Bats came out again to feast on mosquitoes. We heard no bullfrogs (they
have a deep, easily recognized bellow), which is a good thing. Bullfrogs
are alien invaders in this part of the country and resistant to the Chytrid
fungus that plagues other species.
The experience provided a great way for Sharon and me to reconnect with
our inner child and remember the fascination with things that hop and go
plop in the night.
"We are thrilled with the participation we have seen so far," said Erica
Saunders, environmental planner for the city of Fort Collins. "The volunteers
have shown incredible initiative to learn the amphibian calls and make
She reported that the chorus frogs and woodhouse toads I noted are the
most common species in the area, but they are attempting to confirm a few
reports of rarer species. Saunders plans to make the amphibian survey an
"We see this as the perfect kind of volunteer project, one where community
members get out onto the natural areas and have fun learning new things,
and we also receive meaningful information that we can use for management,"
Saunders recommends two web sites for people interested in the amphibian
survey: Find Frogwatch USA, a joint effort by the National Wildlife Federation
and the USGS, at www.nwf.org/frogwatchUSA/. This national web site describes
some species not native to Colorado, but provides lots of species information
and the opportunity to add data to national databases. Find Colorado's
herpetofauna atlas at ndis.nrel.colostate.edu/wildlifespx.asp?grp=Frogs.
This web site provides information on all local herps. Visitors can register
as observers and contribute to the state's database on these important
I'm looking forward to my next expedition to hear frogs croak. Their sound
bites provide far more information than the average politician or sitcom
star, and their messages bear listening to.