Saturday, April 13, 2013

Spring Frog Sounds: Wood Frogs Quacking, Part Two

   As I mentioned in my last post about the wood frogs, I have some video of wood frogs as they call from the vernal pool (see the videos below).  I also have a few more photos of the wood frogs at the pool. 
   Wood frogs normally live the surrounding forest, but in the early spring they congregate at vernal pools to lay eggs. The male wood frogs float around on the water's surface as they call for mates. 
wood frog floating in a vernal pool
  The wood frog's croak sounds like the soft quack of a duck.  When many wood frogs are calling from a pool, they sound like a whole bunch of ducks quacking.  I think their calls carry very far, so I describe the frog's sound as quiet quacking.  Here is a video of wood frogs quacking at the far end of a vernal pool.
    In this next video of the wood frogs calling, you can hear the frog sounds in the background while the camera focuses on one wood frog as it floats across the pool.  The wood frog croaks, or quacks, when he gets about  two-thirds across the screen.  Notice the expanding ring of ripples after the wood frog calls.  Also notice paired vocal sacs that bulge out on the wood frog's sides as he croaks.  The second half of the video is slow motion so the bulging vocal sacs are easier to see.

   I tried to snap a photo of the frog's dual vocal sacs, but I'll have to try again for a quality photo... at least I caught the paired vocal sacs as they bulged out of the frog's sides... just behind its head. 
wood frog's paired vocal sacs
The wood frogs dual air bags are quite different than the big bubble under a spring peeper's throat.  Well, maybe next spring I can get a better photo of a singing wood frog since they seem to be about done calling for this year.
   All this calling by the male wood frogs helps the wood frogs find each other.   When a male wood frog sees a female wood frog, he jumps on her back and doesn't let go until her eggs are laid in the vernal pool.
wood frogs
Some time ago, I posted a post that has underwater photos of wood frog eggs.  May I also remind you that wood frog eggs are solar powered.... see my post about how the wood frog eggs eventually turn green from symbiotic algae.
After the eggs are laid, the wood frogs will leave the pool....
wood frog looks like it has a mask
and head back to their normal habitat... which is the forests.
The masked frogs will quietly vanish into the woods.
wood frog crossing road
Yes, the quiet quacking from the vernal pools is only a short-lived part of the spring frog sounds... Sure was a party while it lasted.!


  1. Now I know what to listen for -- once the snow here melts !

    1. Sybil,
      Try slowly (if they see you, they will shut up for a long time) approaching your wetlands area on a sunny day in the early afternoon... that's when these frogs really go for it with their quacking. Also, wood frogs are early visitors to the vernal pools. Wood frogs arrive with the Yellow-spotted salamanders. They are likely to be there before the spring peepers. I doubt your recent snowfall will scare them off or shut them up. As I mentioned, I made this post at the tail-end of the wood frog's season at the pools here in north-central Pa.
      Good luck!