Friday, March 18, 2011

Wood Frog

A beautiful vernal pool on the floodplain of Little Beaver Creek in Columbiana County. I made a five mile float down the river today wth some colleagues, in search of one of Ohio's rarest breeding birds. We found the goosanders, and more on that in a later post.

At one of our stops, we heard the distinctive quacking clucks of Wood Frogs, Lithobates sylvatica, and entered the forest to investigate.

Two small woodland pools were filled with riotous Wood Frogs in full courtship mode. Their collective clucks, at a distance, always remind me of a far off pack of crows whooping it up.

Wood Frogs may be tiny, but they're loud, and very, very tough. No frog ranges further north than does this species, and they can survive being frozen solid. For a very brief period in early spring, wood frogs enter vernal breeding pools to meet, mate, and deposit eggs. Their noisy courtship antics are about as good a harbinger of spring as anything, and we spent quite some time admiring the frogs.

The females had already begun to deposit their impossibly massive egg clusters. These masses expand considerably as the eggs uptake water; it isn't as if they come right out of the female frog at this scale.

Fresh Wood Frog spawn, up close. In about a month, these eggs will hatch tiny tadpoles, and another two months after that, the tadpoles will metamorphosize into little Wood Frogs and complete the cycle.

Above is a brief video that I made while standing in the vernal pool, surrounded by quacking Wood Frogs. When a person nears a pool full of active frogs, they'll all suddenly clam up and drop to the bottom. The trick is to carefully wade in, and then stand motionless for five minutes or so. After a bit, the frogs bob back to the surface and begin calling, mating, and going on with their frenzied business. It's quite a spectacle.

1 comment:

Anonymous said...

Who doesn't love a vernal pool? Thanks Jim.

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