I can tell the habitat is clean in Maine (no acid mine drainage!) because I saw a lot of frogs while hiking there on vacation.

Here’s one that surprised me by the intricate pattern on his brown back. (not my own photo)

Unlike northern leopard frogs which have circular spots on a green background, pickerel frogs have blob-like rectangles.

It’s useful to know the difference because frightened pickerel frogs excrete a substance from their skin that’s toxic to other frogs and mildly irritating to human skin.  Snakes won’t eat them.

No frogs’ legs on the menu with these!

(photo from Wikimedia Commons. Click on the image to see the original)