Saturday, March 30, 2013

Little Night

Spotted salamander waiting for love. Photo by Burne
In the northeastern US, we’re getting ready for the big start to the spring, as marked by the salamander and frog migrations we've come to refer to as “Big Night.”

The animals that rely on vernal pools for breeding (we’ll do a post on this topic someday and link back to this, we promise) are putting their offspring in something they know is going to dry out. Hurry up or die, kid. This is what makes a vernal pool what it is. Relative safety from a big predator (fish) with the down-side risk that you’ll die a slow, painful, air-soaked death.

To improve chances for little Johnny and EmmaMay, salamanders and frogs get going on breeding as soon as humanly possible…so to speak. They get started on their breeding migration as soon as the ground is thawed and they get a nice, rainy night with temperatures around 40 F (4 C). This results in a highly synchronized breeding migration – lots of animals out and about when conditions are perfect. We’ve come to know this as Big Night. Check out Sarah Lamstein’s book of the same title – we love it.

Salamander thinking "this is not what I meant."
Here’s the thing: lots of people get excited about Big Night, and anxious and stressed over not missing it. In point of fact, it’s a bit of a myth. To be sure, migration in the spring is highly synchronized among vernal pool breeding amphibians, and in some years when conditions are spot-on: wow; it’s something to experience. But if you were just too tired to get out last Thursday night, or you had tickets to the theatre, don’t sweat it: there are opportunities yet to see the salamander stampedes.

North of Boston, there are salamanders in vernal pools (see the first picture, taken last Thursday). I’ve heard reports of wood frogs calling north of Boston on a sunny day early last week. There are even reports of egg masses (whaaa?!). But we haven’t seen the bulk of the migration yet; it’s still early. What we will actually see over the course of a typical spring is a number of “Little Nights” when animals are arriving at their breeding pools and joining the party.

So don’t fret! Get out and check out your local vernal pools regularly through the early spring, monitor roads that have high crossing mortality (be careful, please!), and see the great annual amphibian migrations that mark the start to the spring! ~ MR Burne