Each and every spring, a remarkable event takes place.  On the first warm, rainy night of the late winter or early spring, a massive migration occurs – but for a very short time, as few as one or two nights.  That first warm, rainy night triggers thousands of our mole salamanders across Michigan to emerge from under the ground and move towards one of the most fascinating and diverse wetlands – vernal pools. 

Vernal pools are some of the most productive wetland systems we know of, and are often referred to as “nature’s nurseries.”  Entire populations of wildlife depend on these seasonally wet pockets of wetland which are often found in our woodlands.  The wildlife that inhabit these fantastic isolated wetlands have evolved to withstand the variable wet-dry cycles of the pools, while also capitalizing on the complete lack of predatory fish.  And, so in vernal pools we have fascinating creatures, some of which are known only to these tiny spots of standing water such as fairy shrimp, spotted salamanders and wood frogs.  But, many other species are often found in these pools including copepods, spring peepers, dragonflies, damselflies, Blanding’s turtles, fingernail clams, water striders, garter snakes, amphibious snails, clam shrimp, water beetles, water boatmen, water scorpions, and list goes on and on! 

So take a walk this weekend in the woods, start walking downhill and I’ll bet you’ll eventually run into a vernal pool.  It’ll still have a lot of water in it, so wear your swamp boots, walk to the edge of the pool and look down.  It may take a moment, but your eyes will adjust and you will start to see all of the life that this environment depends on.  Or, just take a look at these two short videos and you’ll never think about the woods in the same way again!

Happy Hiking!

http://www.youtube.com/watch?v=6tlqh9bhbtI

http://www.dnr.state.oh.us/Default.aspx?tabid=23953

Wood frogs are extraordinary creatures.  They are the first frogs we hear in the early days of March in the spring, although during the unusual spring this year I heard them along with chorus frogs and even spring peepers!  Their mating call is certainly unmistakable and can be heard from afar with a resounding cacophony of quacking in our neighborhood woodlands.  However, wood frogs can be very difficult to spot, their brown bodies easily camouflaged in the brown dusky leaves of the forest floor.  

 These frogs not only have a mysterious look, with a thin black mask across their eyes, but they have the remarkable and mysterious ability to freeze...   yes, freeze solid and still survive!  The frogs are able to freeze and enter a state of suspended animation due to a massive input of sugars into the frog’s cells combined with the removal of all water from the inside of the cells.  They remain in this state, without even a heartbeat, for days, weeks, or even months through the winter until the warm spring temperatures thaw them back out.  As the leaves, logs and soils around them thaw, they slowly come back to life for another season of eating tasty insects in the upland woods surrounding their breeding ponds.   

For a glimpse into the freeze-thaw cycle of wood frogs, take a look at the short video at:  http://www.youtube.com/watch?v=Fjr3A_kfspM