An online resource based on the award-winning nature guide

Wood Frogs Awakening and Thawing

4-17-14 wood frog IMG_1377The duck-like quacking of recently-emerged, courting wood frogs is slightly miraculous considering that only days ago these amphibians were frozen practically rock solid. At some point in late fall or winter, as temperatures drop, they flood their bodies with blood sugar that acts as antifreeze in their circulatory system. Activity in their brains stops, their heart stops, and 45 – 60% of their body can freeze. Yet within hours of being exposed to the spring’s warming temperatures, wood frogs thaw out and start moving towards a body of water to breed.

Naturally Curious is supported by donations. If you choose to contribute, you may go to and click on the yellow “donate” button.

8 responses

  1. Allison Bell

    Wood frogs here in the Connecticut River Valley in western Massachusetts have already deposited eggs in vernal pools at lower elevations. Spring peepers, red-spotted newts and spotted salamanders have too! Sub-freezing temperatures forecast for the next 3 nights may freeze the air-exposed parts of floating wood frog egg masses, and will certainly put a damper on the frogs calls until warmer weather returns.

    April 15, 2014 at 1:44 pm

  2. Recently found in Harvard, MA at a large heron rookery. Jan England

    April 15, 2014 at 2:39 pm

  3. I’m worried about the egg masses floating in my little pond…can they survive freezing temps?

    April 15, 2014 at 9:49 pm

    • I’m afraid not, Eliza, if ice forms on the pond…ones that might be attached to a stick on the bottom of the pond will be o.k., though as well as those a bit deeper than the surface.

      April 15, 2014 at 10:08 pm

      • Thanks, Mary, for your quick reply. I just went out & put a plastic lettuce container, like a mini-greenhouse over the egg mass. Hopefully, that will help protect them. I’m crossing my fingers!

        April 16, 2014 at 12:33 am

    • Claudia Wulff

      It is comforting to know that I am not the only one that worries about frog egg masses. I usually return to my cabin off the grid in VT. third week in March, which is when the first wood ducks arrive. This year, because of the long winter, I could not get in until now. I worried about my next door neighbor, the beaver, about migratory ducks, about frogs, the osprey and everybody else. Needless to say, all is well!

      April 16, 2014 at 1:19 pm

      • Good to know, Claudia. I think it is good that there are folks that care about those with “no voice.” I love my dear, wild neighbors!

        April 16, 2014 at 6:11 pm

  4. Brilliant idea, Eliza. I’d love to know if it works!

    April 16, 2014 at 2:19 am

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s