Baby Frogs on the Move — Dispersal in Frogs and Why You Should Care
My husband almost stepped on the little guy. It was a frog hopping across a gravel road in the woods.
This frog was tiny.
This frog looked like it had been a tadpole up to five minutes ago. So, why was the frog cheerfully hopping through the woods.
We were on my mother-in-law’s land, and they have a large pond. It’s artificial, and is home to ridiculous numbers of dragonflies (thank you for eating the mosquitoes) and, from the sound, green frogs (a smaller relative of the bullfrog).
They’re pretty easy to identify. You probably won’t see one, but their call sounds just like somebody plucking a single string on a guitar or a banjo.
Our itty bitty froglet was almost certainly a newly-metamorphosed green frog that had spent their tadpole time in said pond.
So, why was such a young frog hopping across land?
The answer is a reproductive strategy known as dispersal. It’s practiced by a number of frog species. As soon as they are done metamorphosing, the young frogs are instinctually driven to leave their birth pond and find another pond. Meanwhile, frogs from a different pond…you get the picture.
Adult frogs generally, once they have found the pond they like, stay there. They hibernate in the mud on the pond floor and live for several years. (Captive green frogs live about 10 years, but we aren’t sure what’s typical in the wild).
So, I hope our little guy made it to another pond. They can travel about three miles on these journeys.
Thankfully, we didn’t step on him.
(Also, their croak/twang is actually quite gorgeous as frog sounds go!)
So, Why Should You Care?
Dispersal prevents inbreeding and makes for healthier frogs.
And green frogs are your friends. In addition to their kind of pretty song, green frogs eat…well…anything they can catch.
But things they can catch include mosquitos, and anything that eats mosquitos is your friend. (Sadly, they also eat particularly slow dragonflies). Their tadpoles eat algae, helping keep your pond clean.
So, if you see a tiny little frog hop hopping along, leave them be. They’re just looking for a new pond to live in and if you’re lucky they’ll pick your pond.