Vernal Pools: When Will The Spotted Salamander Eggs Hatch?

Posted on March 23, 2009 By Hilltown Families

Sean Chapel writes:

How do we know when a good night will be to see salamanders hatching at a vernal pool?

Sheri Rosenblum of Plainfield, MA replies:

Trying to guess what night spotted salamanders eggs will hatch would be similar to guessing the day of a first snowfall or when that last pile of snow behind the house might melt. Many factors will influence the timing of this event.
While the date of the spring migration is typically in early April in the Hilltowns, the range is late March to late April, depending on snow melt, temperature and rainfall. Once the salamanders are safely in their ponds and eggs deposited, hatch will occur within 4 to 8 weeks, a range that is influenced by water temperature, water level and water chemistry and probably many other factors that we don’t understand.
The whole process of migration to the ponds, mating, egg-laying, egg development and hatching is fascinating to observe. If you know the location of a vernal pond, daily or even weekly visits that start on a migration night will introduce you to the magnificent and ethereal world of the short-lived vernal pond and its many inhabitants.
After the initial migration at night, make your visits to the pond during daylight hours. Bring a field guide to amphibians and one for insects. You will see multiple egg masses, larvae developing within the eggs, predation, birth, death and everything in between. Since the egg masses will be of slightly differing ages within the pond, in time you will probably catch some eggs hatching. If you aren’t sure where to find a vernal pond, get out there during the migration and start following a salamander.
Be careful in the woods, bring a flashlight (with a red filter so the salamanders will be minimally disturbed) and notice how much better adapted they are then us to moving through the forest (and no raincoat required!). Find a pond close to home so observations can be done on foot or by bicycle. They are quite common in these parts.
Happy Spring!