Monday, September 16, 2013

'Tis the Season...

…for metamorphs!

Fall is when a lot of the amphibians that hatched earlier in the year complete the aquatic phase of their life cycle and make the move to dry land. Metamorphosis is quite a feat, and can be a treacherous time.
Metamorphosing amphibians are found around the saturated edges of their natal pools throughout late summer and into fall, hiding among wet leaves and under cover objects, as they complete their change into terrestrial animals.

Spotted salamander metamorph. Photo by Burne
This is a Spotted Salamander (Ambystoma maculatum) that is in the process of completing its metamorphosis. It was found at a vernal pool in Medford, MA this past weekend, and is about 1.5 inches long. Just behind the jaw and in front of the fore-limb is a dark stub, the remnants of the big bushy gills that are so distinctive in pond-breeding salamander larvae. The tail looks short and dark; it is in transition from the larval, flattened, swimming tail, to the rounded adult character.

Finding wee metamorphs is neat, but it’s somewhat dangerous (for them, at least). It’s very easy to step on these delicate little guys and you’d never even know it. Keep an eye out for little wood frogs bounding recklessly around the forest floor, and gently turn logs or leaves at the wet edges of a pool in which you’ve seen eggs or heard a wood frog chorus. Chances are, you’ll get a sweet little reward this time of year. Just don't forget to replace cover objects you turn - remember it's someone's house!

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