Monday, March 12, 2012

Spring migrations to begin

   Throughout the northeast, vernal pool amphibians are primed to make their annual migration to vernal pools to breed.  In doing so, they often are forced to cross roads which provides good viewing for the curious naturalist but can be mayhem for crossing amphibians.  Good family viewing times - early in the evening - are not safe crossing times - better late at night with little traffic.

Spotted salamander on the road.
(photo thanks to
    Mole salamanders and wood frogs migrate from their wintering sites in the uplands to vernal pools for breeding when the conditions are right. The ideal conditions are thawed ground, air temperature in the 40's, rain, little wind, and darkness. Early migrations are sometimes light in numbers of animals. Migrations take place on several nights if the conditions are right.

   This winter has been unusually mild.  Animals are probably ready to move with a good rain.  Some minor movement has already been reported, in some cases without rain, but large migrations have not been observed.  Migrations are usually from mid-March to late-April with the variations depending on the local climate.

   If you go out on a rainy night to observe migrations, do be careful if you are looking at road crossing sites. Drivers will have trouble seeing "salamander people" on the road. Resist the urge to stop traffic to save amphibians. Don't become a statistic. If you find a location with significant roadkill, work with local authorities for road closings in future years.

   Once mole salamanders and wood frogs reach their vernal pool, breeding activities commence. For spotted salamanders, this means the males congress and lay down spermatophores from which the females pick up sperm.Wood frogs commence a "quacking" chorus.

   These animal activities signal spring for many of us.

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