Pond Boss Forums INTRO Questions & Observations Bluegills feasting on tadpoles?

I have all male bluegills in a small 90 by 40 foot pond to hopefully produce large bluegills with no reproduction. Fish are two years of age and up to 7 inches. Fish came out of an RAS but were originally produced in a pond.

Recently I had a prolific hatch of tadpoles and apparently the bluegills are going hog wild over them. Many of the bluegills up all the way up to the edge of the pond with their backs almost out of the water apparently waiting for tadpoles to move so they can suck them in.

At first I was concerned, as a possible sign that something is wrong with the pond or a sign of stress is when fish comes up to the shallow edges of the pond. However the fish do swim off when I get close and are not lethargic. It's impossible to net them. If I net some of the tadpoles out of an adjacent fishless pond, and throw them to the bluegills, they are immediately snapped up. No tadpoles easily visible anymore in the pond with the bluegills(used to be hundreds), but the fish are still in the tadpole eating mode and aren't interested in pellets. Another concern is they may be suspectible to herons although I have not seen a heron visit this pond yet.

Anyone else have this experience? I'm hoping once the tadpoles are depleted they will go back on the pellets. Also I'm hoping the tadpoles are an excellent source of high protein.

Interesting observation, Cecil. The tadpoles are very vulnerable to predation, as largemouth bass will quickly decimate them. However, this is the first time I've heard the bluegill story. However, it's not that big a surprise, is it? Predators generally take what is both abundant and vulnerable.

I was told by my grandfather that tadpoles had a peculiar taste and so were not too heavily eaten by fish. Apparently not so. Maybe the taste was just peculiar to my grandfather!

Actually, Buzz, your grandfather was probably right. You've now opened the door for me to relate what I think is a really cool story.

Bill Lewis was a fisheries professor for years at Southern Illinois University. Many moons ago, he did a really interesting study.

First, he took a look at largemouth bass feeding preferences in an aquarium. I'd have to go look up the actual details, but this is approximately right. Certainly the "point" of my story will be correct.

When given choices of prey items in an aquarium, the bass preferred bluegills first, golden shiners second, and bullfrog tadpoles last! So, your grandpa probably was right. When given prey in a tank where they could be cornered and eaten, the bass had a definite set of preferences.

Next, Doc Lewis moved out to some ponds. He repeated the tests in a pond setting. Guess what the bass preferences were? Tadpoles first, golden shiners second, and bluegills last! So, what was the deal?? I think it comes down mostly to vulnerability. In the pond, the bullfrog tadpoles were slow and easy to catch, so were eaten first by the bass. Golden shiners were moderately vulernable. Bluegills are very quick to maneuver with that compressed body shape, and are the most difficult for bass to catch. Thus, they came in third. So, the order was just reversed between the aquarium and pond studies!

Cool, eh??

Mine are gobling up 1 inch shiner minnows like crazy, which is good because there are thousands from hatches this spring. They pick them off when the minnows go for the feed. I have caught some bream on tiny frogs too. My perception is if they are the top of the food chain they eat most anything. Maybe due to lack of fear?

My observation is a little different. We had millions of tadpoles in our 1/2 acre pond. The banks were a solid black band, 6"-8" wide stacked on top of each other around the whole pond. To help reduce the numbers, I stocked LMB and BG fingerings. To my surprise the LMB weren't interested in them. The tadpoles would swim right by their mouths and not even cause a twitch. We would throw some out away from shore, they would race up to them and swim away.

When the tadpoles lost their tales, we would throw them in as well. The bass would turn away from the tiny toads but the little frogs were gone as soon as they hit the water.

I am not an expert on tadpoles, frogs or toads but it seems the bass are particular (at this stage in life) about what species they will eat. Now that the bass are about 6" long they will still always eat the frogs, some toads but not others.

The BG are not as easy to observe so I have never seen the bluegill eat the tadpoles.

Dave,

To me that study showed exactly what I would expect...that LMB are opportunity feeders first and foremost and will take whatever is easiest for them to get, with the least effort.

In my ponds with feeders, the LMB line up at the feeders waiting for the automatic timer to kick in and expose some fat tasty BG.....a drama played out every day, several times. The BG never learn.

p.s. yes a cool story!

Just as an aside...I fish for catfish in the rivers A LOT. I use leopard frogs whenever available, and they do catch fish, consistently. Seems anything that swims will try to nibble on them. On the few occasions when I wanted frogs, but couldn't find leopards, I've tried young bullfrogs (maybe 4-5" stretched out) and have NEVER had a strike on them.

Don't know what the difference is, but there does seem to one.

I have maybe 575 quadzillion young bullfrogs in my pond right now (20 months old) and the only thing in there big enough to attack them would be a few CC and 3 walleyes. So far, the frogs seem to be doing all right.

Back to the premise of "Optimal Foraging Theory".

Fish, and probably all other animals have an innate ability to calculate calories in (prey) vs. calories out (energy expended during capture). Whatever prey item creates the best ratio is likely to be targeted by the fish.

Animals that can't make this calculations become part of the fossil record.

These are great stories! I grew up with the prejudice that tadpoles were not desirable prey items. I did, however, always catch lots of channel cats and even walleye on leopard frogs. It was the bullfrogs that wouldn't catch a fish.

Interesting. I did take some tadpoles down to the bass pond that also has bluegills. Again the bluegills sucked them in but the bass weren't interested. However these tadpoles are very small (6 to 10 mm) and maybe they are too small to interest the bass. I do feed two sizes of feed (one for bass and one for bluegills and smaller smallmouth bass) and the bass ignore the smaller size.

Still hope they finish them off and return to open water. All those bluegills up against the shoreline make me worry about herons having a field day.

I have however inadvertantly found away to keep them out from the shoreline. We are using a sprinkler to water newly planted grass along the banks. They don't like to be under it.

I have a pond full of green bullfrog tadpoles. 3-4" that are just now starting to get their legs. I have around 60 8"-12" bass stocked to try to control the tads. I also have green sunfish. My pond is a hair over one acre. The bass here seem to have no interest what so ever in the thousands of tads that swim in thier faces. I used to catch green sunfish at 3 to 1 over the bluegills. Now I havent even seen a green sunfish in over a month. The bass have really done well for the greenies but not the tads. I recently had a masive hatching of new tads. And like you are saying Cecil my bluegill are also now hanging tight to the edge feasting on them. There are still a few gills feeding on pellets but nothing like before. Odd to me, this is the exact opposite of what I had figured. My problem now is that the herons are on to me here. My home overlooks my pond so I keep a close eye to shew them off. I ordered a decoy today I hope it works.