Signs of Spotted Salamanders

I took advantage of some nice weather before break to get out with my Maine Fish and Wildlife classes and check in on our local vernal pool. Along the way we made some great discoveries. The duck-like vocalizations of the wood frogs that were so easy to hear a week or two ago are now few and far between. Most have likely completed their reproduction and are in the process of moving back into the nearby forest for the remainder of the year. We came across the wood frog shown below resting in a puddle adjacent to the main vernal pool.

This wood frog hid at the bottom of the puddle upon our arrival but posed for some pictures under water. 

The wood frogs left plenty of egg masses in their wake. Most of them seem to have made it through the recent periods of cold. Only the eggs that were near the surface when the pool froze over were killed. It looks like most of the eggs that were fully submerged and insulated by the water have made it through. No tadpoles hatching yet but we are getting close!

The most glaring change in the vernal pool was the the addition of spotted salamander egg masses. At some point in the week between our last visit the salamanders arrived and completed their life cycle. Much like the wood frog, by now they have mostly moved back into their upland habitats for the remainder of the year. .

A spotted salamander discovered during a past vernal pool trip.

The salamander egg masses are easily distinguishable from the wood frog eggs. They are generally a bit smaller in overall size but he individual eggs within the mass are larger and more distinct. The jelly that surrounds them is thick and much more firm to the touch. While wood frog eggs are typically laid near the surface, salamander eggs are often seen attached to debris deeper in the pool.

Spotted salamander egg masses are typically found deeper in the vernal pool.

Lifting this overhanging tree exposed a large number of salamander egg masses initially hidden by the glare on the water. 

One of our coolest finds on the day was salamander spermatophores (seen below). Salamanders have an elaborate mating ritual that involves almost no contact with one another. Males adhere small spermatophores to debris at the bottom of the pool. The female later uses this tiny packet of genetic material to fertilize her eggs internally. All of this takes place in a mirky vernal pool under the cover of darkness! Leftover spermatophores are typically visible for a short time near the egg masses. It takes a keen eye to spot them at the bottom of the pool but my students did a great job.

Leftover salamander spermatophores.