Saturday, 5 February 2011

Wood Frog in pen and ink

This week's Illustration Friday prompt is reverse, and linking it with a frog will take a little bit of explaining.

Frogs, you see (or at least some frogs), can reverse their gender. I'm not sure if it works for Wood Frogs, but studies of African Reed Frogs about twenty years ago found that females could change into males. Gender switching has since been observed in other kinds of frogs as well.

And why switch gender? Well, in the wild it probably has something to do with making sure that the animals can breed. If there are too many females, for instance, chemical signals may tell some of those females to become male.

That's all well and good in an untouched system, of course, but unfortunately some studies are now showing that chemicals created by humans may cause gender reversal as well. That's not great news. Many amphibian populations around the world appear to be in decline already, and having breeding populations affected by our chemical cast-offs would be a very bad thing.

On a happier note, the Wood Frog population seems to be pretty healthy. I just happened to have an old photo of one on hand (the silly thing was sitting in the middle of an asphalt path in August. I'm surprised it wasn't a shrivelled frog rather than a Wood Frog) so I used it as my source. I could tell you lots of cool things about Wood Frogs, but I think I've yammered enough for one post. Check the link at the start of this paragraph if you'd like more Wood Frogginess.

This was done in my moleskine with Prismacolor Premier pens.


Indigene said...

Great line work and informative post! :)

Linda Hensley said...

Can you ever have enough info on frogs? I enjoyed your post.

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