|Photo of Spotted Salamander by Erica Showalter|
Article by Levi Arnold, Wildlife/Forestry Specialist
A sure sign that spring is upon us can be found not by what day of the month the calendar says it is, but by what nature is doing around us. Yes, it is getting warmer but what I’m really talking about is the wildlife. Our robins are returning, bluebirds are sounding off in the sunshine, but one of the most bizarre sure signs that spring is arriving is the salamander migration. Some of you may be thinking salamander migration? What, do they hitch a ride north with the birds or something? No, of course not, but salamander migration is no less spectacular than that of when birds make their journey back from the south.
Mole salamanders (family Ambystomatidae) come out of upland wooded areas and travel to vernal pools where they breed. They spend most of their lives underground and out of sight. A night after a few days with temps in the fifties after a rain, typically early in March is when this mass migration takes place. Many of these salamanders are killed during this time of year due to habitat separation. Roads often separate the upland woods from the lowland vernal pools so salamanders are forced to travel across roads where they often meet their fate between tire and asphalt. Males are the first to arrive at the breeding grounds to await the females and typically outnumber the females.
Now that you’ve heard the term a few times you may be wondering, what’s a vernal pool? A vernal pool is nothing more than a shallow seasonal wetland, typically only holding water for a few months out of the year in the spring and sometimes in the fall. These seasonal wetlands are crucial to Ambystomids because they provide them with the habitat needed to ensure their eggs reach maturity and hatch. Vernal pools are used because fish can’t inhabit the pools because they dry up; otherwise the eggs and salamanders would mostly be eaten by fish. The most common and recognizable species here in southeastern Ohio is probably the Spotted Salamander (Ambystoma maculatum) which lays an egg mass that contains between one-hundred and three hundred eggs. These salamanders migrate in masses and it’s not uncommon to find several in one vernal pool. A male salamander produces a spermatophore which the female takes into her body to fertilize the eggs. Female salamanders will attach their strand of eggs to some debris in the pool where they will hatch in couple weeks. The eggs appear in masses from a jelly like substance that the females put on the eggs that expands when it comes in contact with water.
Looking for salamanders is a fun activity that can be enjoyed by the whole family. Many SWCD’s, state parks, and nature conservancy’s put on salamander hikes where you can go learn more about these interesting amphibians. For more information about salamanders in Ohio, the Ohio Division of Wildlife puts out a free Amphibians of Ohio Field Guide which is really helpful and full of great information.