Saturday, March 3, 2012

The Cold-Blooded Signs of Spring

John Strickler's Mercury photos from the 2009 migration
So I need not tell you that given the near total absence of winter weather this year, it may be hard to figure out when spring gets here.

After all, the daffodils in my yard started breaking the surface in February and the birds are already trying to rebuild their nest in my front door transom.

But one group of people who know when spring has definitely arrived usually make that determination when standing on the side of the road on a dark, wet night in the woods of western North Coventry near French Creek State Park.

They are there to help their cold-blooded amphibian friends -- wood frogs, spring peepers, spotted salamanders and, more particularly Jefferson salamanders -- across the unlit road to a particular vernal pool.

As I wrote in 2009 when reporting on this story for The Mercury, "it is the conditions and not the calendar which dictate when this migration occurs."

The migrating salamanders can be hard to see at night
"It has to be above freezing and damp and rainy for the salamanders, and the wood frogs who favor the same conditions, to make the short but perilous journey,"

And it turns out, that the conditions conspired with the calendar to make sure irony had a hand in this year's migration which began, on all days, "LEAP DAY!"

According to Kim White, the volunteer who coordinates the road crossing patrol and keeps a close eye on weather conditions at this time of year, that was the day the leaping began.

"Leap Day certainly had the right name because we saw a lot of leaping Wednesday night," White wrote to those on her "amphibian friends" e-mail list.

"The migration started slow (just like the rain) and then momentum picked up and there was a steady stream until we called it a night a 10:30. Luckily there wasn't many vehicles. Thank you to the die-hard volunteers who did come out. They had their hands full (literally with slimy friends). Here are the tallies:

Spotted Salamanders 161
Jefferson Salamanders 6
Wood Frogs 80 
Spring Peepers 3

"Sadly, we did have 6 spotted, and 6 wood frog casualties. 

"Last night we heard the wood frogs singing for the first time. Spring has come early here!

Kim White, right, with volunteers in 2009
The conditions have to be right for the migration to begin. 

It has to be above freezing and damp and rainy for the salamanders, and the wood frogs who favor the same conditions, to make the short but perilous journey.

What makes the journey perilous is traffic.

To avoid predators, the salamanders and frogs typically choose a dark night to make their journey, but that also makes them nearly invisible to drivers on the unlit roads.

And that's why they need a little help from the same species that poses the greatest threat.

The volunteers, who wear luminescent safety vests and, in some cases, head lamps, are not allowed to stop traffic on the one country road involved, although the township does allow the stopping of traffic on the other.  

A vernal pool appears only in spring with no egg-eating fish
When they see a car coming, White instructs them to "scoop up as many salamanders and frogs as you can, put them in a bucket and move them to the side of the road that most of them seemed to be going."

They're going both ways because some are on the their way to the pool to spawn, and others are finished.

The pool in question is called a "vernal pool" because it appears in the spring and by late summer, it has dried up.

It is on White's property and she said she and her family intend to ensure that it is preserved in perpetuity.

Wood frogs literally freeze in winter
"They need the vernal pool because it dries up so there are no fish in it to eat the eggs," White told me last year. 

So where have they been when they're not spawning in the pool? Well the wood frogs were literally frozen solid during the winter.

"The wood frogs actually freeze, and the scientists are still trying to figure out how they do that," said White in 2009. The salamanders spend the winder in abandoned burrows, usually made by small mammals.

Among the salamander species using the pool is the Jefferson salamander, an endangered species.

The Jefferson blue spotted salamander, endangered and living in North Coventry
"The herpetologists said this the place nearest Philadelphia that they still spawn," White said. "Between here and the city, they're all gone."
As the season begins, White is still on the job.

"I am watching the weather for tonight and hoping the rain holds off until late so our friends can cross without traffic," she wrote in her e-mail Friday.

If you would like to volunteer to help the frogs and salamanders cross the road, you can contact White via e-mail at

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