A little over a month ago, the familiar nightly chorus of breeding Pacific tree frogs started up again as it always does. Over the years, the "singing" has gotten so loud it borders on deafening. This year it started up with a few then grew, but suddenly the nightly sounds of "romance" stopped. I thought it was very odd and figured maybe our heavy rainfall had sent the little frogs back in their hidey-holes until a later date.
About the same time I stopped hearing the tree frogs, I realized that every time I approached one side of the pond I would see a quick movement and hear a splash as something jumped from under the pond-side plants into the water. For weeks, I only caught little glimpses. I've had a pond-swimming mouse that regularly swam across the pond to get from one side to the other years ago, so I couldn't be sure what it really was... until two days ago. I was finally able to sneak up on the critter and get close enough to see that it was an amphibian larger than the tree frogs. But I still couldn't tell if it was a toad or a frog and definitely couldn't identify the species.
Today, I ventured out and found TWO frogs sitting around basking in the spring sun. I got my camera and snapped some shots so I could compare them with online photos to get a positive I.D.
Unfortunately, my worst fears were realized... they are bullfrogs. Bullfrogs eat other frogs so that would explain the absence of the nightly chorus. Bullfrogs also eat fish, birds, reptiles, invertebrates, mammals... basically anything that will fit in its mouth (including other bullfrogs). They're lazy hunters that sit and wait for their prey to come near them, then lunge after the prey. And according to one source bullfrogs are unpalatable to many predators. Great.
So the first thing I did was search the internet to get some idea of what I could humanely do to give these two an eviction notice before all my fish, lizards and everything else in my backyard wildlife habitat goes missing as the tree frogs have.
I googled "what eats bullfrogs". The following answers made me hopeful:
- Birds: herons, egrets, kingfishers, ducks
- Mammals: Racoons, opossums, bobcats, coyotes
- Reptiles: garter snakes
Another internet source says that bullfrogs "like warm, quiet areas with dense plants". Okay.
So guess what I did for the entire day... I removed all the weeds from around the pond and made lots of noise while doing it!
Unfortunately, although the frogs seemed startled by my presence at first, they chilled out after a while. One let me go so far as push on its rump with the pond net for about 10 seconds as I said, "Go away. You aren't welcome here." It finally got tired of me bumping its rump and jumped back into the pond. Sigh.
Well, it looks like I'm going to have to put all my faith in the egrets, raccoons or opossums. And I'm hoping my naturalized pond goldfish love frog eggs.