Tadpoles and bullfrogs are common in ponds. Even when it’s hiding, it’s hard to miss the male bullfrog’s loud, growly croak. Female bullfrogs can lay up to 20,000 eggs. Many of those eggs don’t survive, but those that do hatch into tad- poles, which then take up to three years to lose their gills and tails, fatten up, and grow legs to become frogs. You can tell a male bullfrog from a female by looking at the tympanum, or eardrum, near the eye. In males, it’s much bigger than the frog’s eye, while in females, it’s about the same size or smaller. When a great blue heron is hunting, it wades slowly or stands still as still can be, eyes on the water. Then, in a flash, it thrusts its head into the water and uses its bill to stab a fish or a frog. Great blue herons have special photoreceptors in their eyes that help them to see better in the dark, so they can hunt day or night. Pileated woodpeckers hammer away at trees in the forest, searching for insects. Carpenter ants are their primary food source. The woodpeckers dig long, deep, rectangular holes in dead or dying trees, right into the ants’ tunnels. These birds have powerful beaks and long, barbed tongues for pulling out beetle larvae and termites from the wood. River otters live in burrows on the shores of lakes, ponds, rivers, and marshes and come into the water to hunt for fish, freshwater mussels (which they crack open on rocks), crayfish, frogs, and turtles. They’re excellent swimmers, with powerful tails, webbed feet, and ears and nostrils that close in the water. River otters can hold their breath underwater for up to eight minutes.
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