University of Wisconsin-Madison Skip navigationUW-Madison Home PageMy UW-MadisonSearch UW



An Alumni Fish Story by: James Gammon

During the 2011 and 2012 spring/summer/fall survey of fishes in Black Dan Lake’s littoral zone the following unusual observations occurred.

It involves a single eight inch long largemouth bass which took advantage of my routine of tending minnow traps at my dock on North Bay. In early July I regularly observed two largemouth bass (LMB) in the dock region, an eight inch fish in company with a six inch individual. On July 8, 2011 I became aware that these two bass were attacking and often eating the small AG1 bluegill that I returned to BDL after their removal from the minnow traps. From that date until mid-September, after which most fish moved into deeper water, the larger of the two bass regularly greeted me as I tended the traps near my dock.

My regular routine consisted of tending traps about 0630 walking from our cabin downhill to the lower dock, kneeling down, measuring and then recording the water temperature. I would then, still kneeling, retrieve the shallow minnow trap to remove and identify its contents fish by fish and throw each one back into the lake. At some point the LMB began immediately eating the small AG1 bluegills which were the primary species captured. They moved with me then to the floating dock where the deep minnow trap was located and repeated their predation. The smaller bass disappeared early on, but the larger one continued that routine. Eventually, I found that this LMB spent the night under the fronds of two large clumps of ferns adjacent to the dock and, alerted by my soft tread on the dock, swam toward me and our boat, then under the dock and positioned itself immediately to my left near shore. When a small bluegill was returned to the lake the LMB charged out striking and eating the breakfast offering.

News of the unusual “pet” bass gradually spread around BDL. One afternoon neighbors walking their two golden retrievers stopped by and asked if they might see this oddity. I told them that I had only experienced this phenomenon early in the morning, but let’s go down to the dock and see. I wasn’t at all sure that the bass would respond in its usual manner, even if it was there, or if it might not behave “normally” when more than one person was present. However, upon our arrival at the dock out it came from beneath the fern fronds and leisurely swam toward us as usual. The bass was not rewarded, but it behaved normally next morning nevertheless.

One memorable day when I was taking the water temperature the bass’s head slowly emerged from under the edge of the dock near the lake’s surface and tilted, looking at me from a distance of perhaps only 15 inches or so. After a few seconds it slowly retreated back under the dock. Was it unusually hungry or was I too slow in delivering its breakfast or both? The bass would then accompany me as I moved out to the deep trap where it “faced” me near the surface about four feet from the floating dock waiting for the trap to be lifted and resume the routine. On August 6 the deep trap yielded 1 rock bass and 54 bluegill each of which was measured for total length and recorded by my wife, Sherry. We carefully watched as each one was tossed back into the lake after being measured. The bass ate 9 of the first 12 bluegill tossed back. Several more were consumed, but we lost count. The small rock bass was returned to BDL a safe distance from the bass.

There is little doubt that our catches of small bluegill, sunfish, etc. from the shallow net were much reduced because of the predation by this bass since physical habitat was limited, unlike the protection afforded by the deep set in the macrophyte bed. Therefore, in August I moved the traps to a shallow protected area a short distance away, but continued to dispose some of its contents at the dock.

That bass grew to 12 to 13 inches in length by September when it finally departed into deeper water with the other fish. It had learned my daily routine and took advantage of it. It had to fend for itself in the interval of about two weeks between monthly sampling periods, but may or may not have continued to use the protective fern fronds. However, it required only about two days after sampling resumed to return to its regular breakfast routine so its retention of past events was fairly good. Judging from its behavior it also learned that I was not a danger to it.

Never before had I ever felt an actual personal connection between one of my aquatic “subjects” and myself. I can hardly wait until next summer comes to find, hopefully, that “my” friendly LMB had survived the winter to resume its breakfast behaviour. That would really be remarkable!

Fish, in general, never seem to be included among the “intelligent” animals of our world. Mammals and birds are much more frequently the targets of study. Obviously, there is so much more to learn in that regard.

2012 Update regarding the “special” Largemouth Bass of Black Dan Lake

After Mother’s Day, Sherry & I began trekking North on Monday May 14, 2012 overnighting at Comfort Suites in Stevens Point, Wis. Up early next day and completed trip to cabin before noon. After unloading, the minnow traps were placed in BDL near shore in water about 15” deep and at the end of the stationary dock in 3’ deep water.

Traps were examined at 0700 May 16, 2012. The temperature of the surface water near the shallow trap was 62.3 degrees F. and air T 39F. Weather was clear, cold and calm with fog over the lake which slowly dissipated as the morning wore on. No fish were found in the shallow trap, but there were 8 bluegill in the deep trap. Five bluegill measured 3.5” in total length, three were 3.0” and one was a very small Age Group 1 at 1.6”.

The bottom of BDL at the dock’s end was coated with a dark layer of dead and decaying leaves. Despite the calm and clear waters it was difficult to see clearly. As I measured the first large bluegill and returned it to BDL it was immediately struck by a fish which I could not really see clearly. What a unexpected surprise! A smaller bluegill was then measured and returned with the same result and then a third. A largemouth bass about 10 to 12 inches long swam slowly to my right and then toward shore, its mouth distended as if it had engulfed a fish which was positioned sidewise and, therefore unable to swallow. This had to be the same LMB that accompanied me last year for most of the summer.

For the next two days there was no sign of any LMB and I began to worry that “my” LMB might well have been unable to reposition its prey to either release it or swallow it. However, on May 19 (Saturday) morning it reappeared swimming toward me over the light colored deep trap expecting I am certain some breakfast. Unfortunately, there were no fish in either trap to feed it and I must reposition the shallow trap as I was forced to do last year. Tomorrow, I hope to have something for it to eat. Until then, I wait in anticipation virtually certain that this particular LMB is the same individual which “adopted” me last year. If so, it has retained a memory of last summer’s events for more than seven months of a cold, dark winter from late September, 2011 to mid-May, 2012. Additionally, it has been able to avoid capture by resident walleye and musky which continue to feed under the ice. Where has it overwintered? Perhaps close to our dock.

On Sunday May 20 the shallow minnow trap lacked fish, but contained two crayfish, one quite small and another medium-sized female in berry (carrying eggs). The deep trap contained a single AG1 rock bass, which was thrown back safely into shallow water, and 12 bluegill; 10 small (circa 2”TL) and 2 older ones. Although the bottom was covered darkly by last fall’s leaves the LMBass was observed to eat all 12 near the lake’s surface and also, thereafter, the crayfish. The bass is, indeed, back! It seems likely that the newly set minnow trap was observed by the LMBass and was an indication that we had returned.

A strong south wind kept visibility low for the next three days (May 21, 22 and 23) and the bass was not observed. Thursday, May 24 however, dawned calm and clear.. Mr/Mrs LMBass ate all 12 AG1 (1.75”TL) bluegill one by one cruising unconcernedly within one foot of my hand on one occasion. Sherry thinks that I should attempt to hand feed it, but I am hesitant.

June 15, 2012. “Our” LMBass has continued to “breakfast” every day the traps have been in place. It eats only the larger sunfish and now ignores the smaller Age Group 1 fare. It also seems a bit more wary, but maybe this is because it now occupies a larger, more open and darker environment. I don’t know exactly where it now overnights.

June 17, 2012: No fish were found for several days in either of the two minnow traps set at the Subera dock located in the South Bay. Today two small bluegill were taken in the shallow trap. When thrown back they were eaten by an eight inch long largemouth bass. It seems that the intelligence exhibited by “our” LMB may also occur in others. This development will be watched with interest in the future.

Also on June17 there were four bluegill nests immediately adjacent to the shallow trap, each guarded by a male bluegill. These were not present yesterday. Each day thereafter the number of nests increased; as of June 21 there were 14 nests and increasing numbers of very active bluegill as well. Active spawning continued through June 23, 2012. On that date, significantly, three small six to eight inch long LMB patrolled the shallows. The larger one ate some of the smaller bluegill from the trap one by one as they were thrown back. It appears that intelligent LMB may live throughout our lake.

The next question is: Is this intelligence a population phenomenon limited only to “our” lake or is it a species specific attribute which is broadly present in largemouth bass everywhere? I suspect that the latter is most likely so an alternate question is: Do any other resident species of fish have this same capacity? I rather doubt that any other gifted individuals of walleye or muskellunge will reveal themselves for a comparative study so that question will remain unanswered.

July 16, 2012. The LMB continues to expect breakfast and has faithfully shown up each day. For several days I placed a second minnow trap about one hundred feet north of our dock close to shore in a heavy mix of bulrushes and submergent vegetation so as to obtain sunfish of a favorable size to feed the LMB. Who is training who? I will now remove all traps until August and force the LMB to fend for itself. A week later while working on the lower deck, I took a break and checked out the shallow sandy bottom area which is our small bathing “beach”. There was the bass facing me and, I guess, wondering just why I wasn’t feeding it breakfast. First time I ever saw it there. After a bit when I didn’t do anything, it swam in a circle just like a dog does when it isn’t fed its expected food.

On August 9, 2012 the deep trap at our dock was reset and a few days later the bass returned and continued the breakfast routine.

For four consecutive days starting on August 26, 2012 Al Subera attempted to capture underwater photos of Mr. Bass (from this point on I will refer to this largemouth bass as Mr. Bass even though its gender is unknown). The first day’s attempt was particularly colorful since Al donned his full SCUBA regalia (wet suit, mask, belt weights, etc.) and floundered about in the weeds near the floating dock trying vigilantly to position himself in reference to Mr. Bass. Remarkably, Mr. Bass was not deterred by all the splashing only six feet away and kept his usual position. This effort was unsuccessful.

During the next three days Al attempted to photograph proceedings by lying prone on my left and holding the camera submerged as I fed bluegills to Mr. Bass one by one. A few videos showed some of Mr. Bass but the velocity of his rush overpowered the capability of the camera and, again, no good pictures were obtained.

Perhaps the most striking thing about this whole experience is that Mr. Bass continued his usual routine. He faced me and basically ignored Al and the camera except for a single time when Al extended the camera toward Mr. Bass attempting to get a close-up. On another occasion, one bluegill was poorly thrown in the water very close to the held camera and Mr. Bass actually bushed by Al’s hand as he pursued the food item. Mr. Bass at this time is approximately 15 to 16 inches long and noticeably stout.

Breakfast with Bass resumed after a few days off for a Labor Day family gathering at Kendall. Prior to Labor Day Al Subera’s under-water photos were worked on by friend and pc expert Sandy Kernan with surprisingly good results. So good were they that Al insists that he can get even better ones in color in a couple days by again emersing himself. So few bluegills now are entering the minnow trap that I am forced to fly-fish for breakfast items of the preferred size. Again, who is the trainer in this unlikely relationship?

Trap catches diminished to a single young of the year (yoy) earlier this week and the minnow trap was removed on September 29, 2012. Water temperatures have declined to the low 50 degrees and most fish have moved to deeper water offshore. The LM bass was noticeably skittish and almost nervous in its behavior recently perhaps the result of the change in water temperatures. Soooo, it’s all over for this year. Will Mr/Ms bass remember me again next March/April? Will it again survive predators? Time will tell. Will I survive another Indiana icy winter or perhaps spend time in the newly acquired log house near the cabin? Again, time will tell.


Mr/Ms L.M. Bass about to eat a breakfast bluegill
Mr/Ms L.M. Bass about to eat a breakfast bluegill

J. R. Gammon
Emeritus Professor of Zoology
DePauw University
Greencastle, IN 46135

Update: This year (2013) the bass failed to reappear when I again set out minnow traps in May. I can only surmise that it may have been caught by an angler or perhaps eaten by one of our larger muskellunge. Anyway, I was quite surprised about how "empty" our lake seemed to be without its presence. I have gradually lost that feeling as summer progressed and other more positive developments occurred (the otter family again entertained us and our loons produced two chicks (they failed to do so for three successive years).

Department of Zoology | UW Home | Biology in L&S