Chubby American Bullfrog

A few weeks ago I got a picture of an American Bullfrog that looks kind of chubby. This was taken in the rain garden just west of the Duke Farms parking lot, probably aided by the water level being a little low. This meant the dense vegetation that's usually there wasn't interfering with my line of sight. (FWIW the water level is even lower now.)

I don't know if the frog looked chubby because the location was providing an excellent supply of food, or if something more reproductive was going on. Female bullfrogs that are ready to lay eggs tend to look plumper. If this is a female preparing to lay eggs, she'll be selecting a handsome male bullfrog soon as her mate. They'll find a romantic spot in the water, he'll climb on top of her, and she'll release her eggs (up to 20,000 of them) directly into the water, and he'll release his sperm onto those eggs in the water (external fertilization). 

So next year I should see 20,000 bullfrogs in this spot, right? Not really. This fertilization method probably means a nontrivial percentage of the eggs won't even get fertilized. Even if there are no fish in the water (which is probably the case here), tadpole mortality is still extremely high. When they're small enough, arthropod predators no doubt take their toll. As they get bigger, they're on the menu of shorebirds, ducks, herons, turtles, snakes, and even other frogs. 

June 2, 2022 at Duke Farms
Photo 205022033, (c) jpviolette, some rights reserved (CC BY-NC)


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