Fall has arrived, despite summers warmth continuing to linger. For many people, this means breakout the pumpkin spice, costumes, and candy corn. For a select group of weirdos, however, the onset of autumn signals the return of some remarkable “gummy lizards” from beneath the earths surface.
They’re called Marbled Salamanders. Ambystoma opacum is its scientific name, and that first bit, Ambystoma, represents a unique group of amphibians called the Mole Salamanders. These striking amphibians, along with other members of the genus spend the majority of the year underground doing whatever it is that mole salamanders do. However, the Marbled Salamander is unique in its activity and does things a little bit different.
The standard phenology, or seasonal life cycle events of other Ambystoma species goes something like this: With the onset of early spring, as the snow melts and we receive our first substantial rains, Yellow Spotted, Blue Spotted, and Jefferson Salamanders make their way to temporary wetlands in a mass migration. These migrations are driven by reproduction, as the pools they migrate to (by the hundreds) is where they’ll mate and where females will lay their eggs. After this fiasco, both males and females head back to their underground refugia some distance from the pool. Several months later, long after their departure, summers heat has dried those pools. The eggs have since hatched, metamorphosed, and left the pools as well. A wetland once thriving with life is reduced to nothing more than a dried up forest depression… or so you would think.
When all of the other amphibians have left, and the water has evaporated, Marbled Salamanders have a migration of their own. On rainy September nights, hundreds of these chubby little monsters make their way to vernal pools devoid of water. Shortly after mating, beneath leaf litter, logs, and other debris, females lay their eggs. As the rain continues through October and November, those vernal pools fill back up with water, triggering the Marbled Salamander eggs to hatch, and the adults to take a hike. Remarkably, females will guard their eggs until the pool fills with water!
It’s worth noting that while Marbled Salamanders are typically smaller than their sympatric relatives, larvae born in the Fall get a head start on their cousins who won’t be born until the following spring. Also, Marbled Salamander larvae are voracious predators, and they’ve been found to eat the larvae of other amphibian species!
I like to think of Marbleds as the hipsters of the mole salamander family. While most Ambystomatids do their partying in early spring, Marbled Salamanders have isolated themselves to do their business in the fall. I don’t know that this post will alter your list of favorite things about Fall. But hopefully, the existence of these amazing amphibians can at least add to your list.
Until next time, Happy herping!
- Sebastian H.