Bulbous, bumpy, bellowing, beautiful bullfrogs are out sunning themselves in the wetlands at the bridge.
They are 3.5 - 8 inches long, and they are the largest frog in North America. They have a large tympanum (eardrum) located just behind the eye. A ridge goes from the eye, around the eardrum and down towards the front leg. They have no dorsolateral ridges. They have a deep-pitched mating call that sounds like jug o’rum. Their diet includes fish, amphibians, birds, reptiles, small mammals and insects.
Bullfrog tadpoles are large at 4 - 6.75 inches, and their metamorphosis may take up to two years.
They were introduced to the western United States. Their natural range is east of the Rockies where they have natural predators to keep them in check. Oregon Dept. of Fish and Wildlife (ODFW) lists them as an invasive species that adversely affect native populations by devouring native turtles and frogs. ODFW also says that “bullfrogs can lay up 20,000 eggs each season while native species such as red-legged frogs lay up to 5,000 eggs.”
