24 March 2012

Frog and Toad Call Quiz - Answered!

I recently posted the following frog and toad call quiz...

Lindsay and I visited several sites over the last few evenings to conduct frog and toad call monitoring as part of FrogWatch USA.  Below is a clip from Chamberlain Lake Nature Preserve.  What species do you hear?

If you turn your volume up to 100%, you'll hear these amphibians at roughly the same decibel level that we did.

Nice job to those who provided answers!  In the video/recording, you should be able to hear both Spring Peeper (Pseudacris crucifer) and American Toad (Bufo americanus, or Anaxyrus americanus).  Also calling during the video/recording is Northern Leopard Frog (Rana pipiens, or Lithobates pipiens), but due to the volume of the other two species I cannot here the latter in the recording.

Pound for pound, Spring Peepers (above) are said to be the loudest animals on earth.  At just 2.5 cm long and weighing in at only 3-5 grams, the "peep... peeper" calls of this tiny amphibian measure 110-120 decibels from 10-20 cm away.  For comparison, a jet engine 120 feet away produces a sound measuring 120 decibels!  Considering that Spring Peepers are often found by the hundreds or thousands in wetlands, you can see how a chorus produced by this species can be deafening.

The call of the American Toad (above) is much more melodic and beautiful than you would expect from a creature with warty skin that produces bitter toxins.  The flute-like trill that lasts up to 30 seconds long is belted out at approximately 90 decibels.  For comparison, an average conversation measures at approximatley 60 decibels.  When a group of American Toads is calling at the same time as a group of Spring Peepers, it is nearly impossible to hear anything else, and you leave with the same sensation you would have after leaving a rock concert.

By contrast, the call of the Northern Leopard Frog (above) is much softer and lower pitched, sounding like a slowly opening creaking door or a deep snore; this species also produces a sound that is earily similar to the sound made when you rub your hand on a balloon.  Northern Leopard Frogs are generally less abundant than either of the two previous species in a given wetland, adding to the difficulty in hearing them when other species are calling.  In fact, the Alberta Fish and Wildlife Recovery Plan for Northern Leopard Frogs points out that loud calls of other frog and toad species can make it difficult to hear Northern Leopard Frogs.

It isn't even April yet and I've heard seven frog and toad species calling.  It will be interesting to see how the year plays out as the calendar catches up with the weather.


Anonymous said...


Scott Namestnik said...

... and?

Here's a hint... there were three species calling when I took the video. I couldn't hear one when I replayed the recording.

Anonymous said...

American Toads, trilling