Spring migration of spotted salamanders and wood frogs
Spring migration of spotted salamanders and wood frogs
A vernal pool
A vernal pool
My pond is a "vernal pool", which means it is used by certain specific species for breeding in the spring. Most vernal pools are just a big woodland puddle, filling up in the spring and drying up over the course of the summer. The salamanders and frogs who use it for breeding lay their eggs and then head back to the woods. The offspring hatch, metamorph, and leave before the pond dries up.
But, as you can see from the other pages of this site, this pond is more than the typical vernal pool. While it IS a state-certified vernal pool (verified by the presence of certain breeding species, including wood frogs) it doesn't dry up, so there is also a large population of year-round frogs and turtles in addition to the spring-only visitors. It has no fish, which is typical of a vernal pool.
But, as you can see from the other pages of this site, this pond is more than the typical vernal pool. While it IS a state-certified vernal pool (verified by the presence of certain breeding species, including wood frogs) it doesn't dry up, so there is also a large population of year-round frogs and turtles in addition to the spring-only visitors. It has no fish, which is typical of a vernal pool.
The "big night"
The "big night"
Every March, like clockwork, the first rainy night after the 15th that’s 40 degrees F (5 C) or warmer launches the spotted salamander and wood frog migration from the woods across the street, over the road, and down to the pond. The rain helps to thaw them out (yes, they actually freeze during the winter!) and keeps their skin wet as make the trek to the pond.
The road - good for us, bad for them
The road - good for us, bad for them
The road crossing provides a great opportunity to see them, because they are nearly impossible to see on the yard grass or the woodland floor. It also provides a serious risk of car-hits, so carrying them across the road is part of the fun on Salamander Night.
Since the road is an an unavoidable obstacle in their path to the breeding pond, there is no learning to be done in how to avoid it, so there is NO evolutionary advantage to the gene pool in letting them get flattened!
Not exactly a "herd"
Not exactly a "herd"
It's not like a herd of African wildebeest swarming across the street. You'll see one over here, one over there. Over the course of a few hours, perhaps 20 salamanders and 20 wood frogs will make the crossing. A flashlight and a sharp eye will reveal a nice assortment of critters. And always, watch where you step!
Salamander Night dates
Salamander Night dates
The standard rule of thumb is this: The first rainy night after March 15 that's 40F (5C) or warmer.
2007 – April 1
2008 – March 31
2009 – March 26
2010 – March 13
2011 – ?? They managed to sneak across when I didn't expect it. I think it must have been one night when there was a thin layer of wet snow, and I didn't think they would travel in snow. But apparently they did, because there
wasn't another rainy night before the wood frogs started quackling in he pond!
2012 - March 13, after a hailstorm!
2008 – March 31
2009 – March 26
2010 – March 13
2011 – ?? They managed to sneak across when I didn't expect it. I think it must have been one night when there was a thin layer of wet snow, and I didn't think they would travel in snow. But apparently they did, because there
wasn't another rainy night before the wood frogs started quackling in he pond!
2012 - March 13, after a hailstorm!
Once the travelers are installed in the pond, next comes the audio bloom of peeps,
quacks, and chirps as the pond explodes with the exuberant sounds of courtship for the next few weeks.
quacks, and chirps as the pond explodes with the exuberant sounds of courtship for the next few weeks.
Salamander Night 2010
March 13! Unusually early
March 13! Unusually early
Salamander Night 2009
March 26
March 26
Click here for more pictures
My friend Emily and I went out with flashlight and camera to watch this amazing rite of spring. We flagged down curious passing drivers while we scooped up the critters in the road and delivered them safely to the other side.
During the two hours we were observing, about 15 salamanders and 20 wood frogs crossed. It dropped into the upper 30s (3 C). While our warm-blooded fingers were getting numb, their cold-blooded feet were still on the move!
During the two hours we were observing, about 15 salamanders and 20 wood frogs crossed. It dropped into the upper 30s (3 C). While our warm-blooded fingers were getting numb, their cold-blooded feet were still on the move!
Spotted Salamanders look like their spots were cut
out of bright yellow plastic and glued on!
You can identify individuals by the pattern of their
spots – each salamander is different.
out of bright yellow plastic and glued on!
You can identify individuals by the pattern of their
spots – each salamander is different.
Down from the woods, at the roadside, ready to cross
The wood frogs migrate the same night as the spotted salamanders
Two different shades and sizes of wood frog (does anyone out there know the significance of this?)
Note that the lower one has partially inflated side-panels - just can't wait
to get to the pond and start making noise!
(For a picture of a properly inflated wood frog, go here.)
Note that the lower one has partially inflated side-panels - just can't wait
to get to the pond and start making noise!
(For a picture of a properly inflated wood frog, go here.)
Oops! Where's the pond?
Salamanders and frogs would turn up on the doorstep
Salamanders and frogs would turn up on the doorstep
Hand-carry when cars come by
Ahh ... floating at last !
A couple of the wood frogs began to make their "quackle" sound
as soon as they got to the water – the spring awakening of the pond!
as soon as they got to the water – the spring awakening of the pond!
This is the road they crossed, and the pond they plopped into.
Notice there is still ice on the pond!
They don't seem to mind navigating patches of snow in the yard.The Morning After