Photo by Ron Sinfelt

A typical day on the ice chasing Wisconsin walleyes this time of year starts out slow, and then slacks right off once the sun comes up. But the all-too-brief active bite for these notorious nighttime raiders comes at midday when the sun is shining on some of our hardwaters, providing ample opportunities for a fresh walleye dinner without a need to be out there when the owls go hunting.

Fisheries biologists will tell you walleyes are crepusculent feeders -- a 10-cent word that means these fish are most active during periods of low light. You only need to glance at those opaque eyes for a minute to realize why this is so.

Walleyes working in the role of predators quickly learn the advantage of seeking dinner when minnows and other prey believe they are hiding safely in the darkness. With slowed metabolism in cold water and a perpetual Arctic high-pressure system in place over the state putting a squeeze on Walter’s air bladder this time of year, the active feeding window can be 30 minutes or less in a 24-hour period. Even when weather conditions are “mild” by Wisconsin standards, the bite may only last an hour at dawn and again at dusk, with a flurry of flags followed by hours with nothing better to do than count your minnows.

On classic lakes with clear water and structure, you can actually see when walleyes go on the move, tripping tip-ups as they slide ever shallower on a hump or rockpile to feed during those brief interludes between night and day and ahead of approaching weather systems.

Flowages can offer a stark contrast to the activity pattern found on lakes, with stained water creating visibility problems for sight-feeding walleyes that clear up with a little help from the sun. The midday pattern that flowage anglers take advantage of all summer long also tends to hold true during winter months, with a feeding window that lasts longer than is typical on clearer Wisconsin winter waters.

Most flowages are either basins with a nearly uniform bottom structure or a series of flats and dropoffs found where the old river channel ran before the flowage was created. In a basin-bottomed flowage, fish tend to stay on the move, casually dogging their forage base until an opportunity to eat without effort arises. The location of this forage base is often driven by current, with bait location changing as flowage levels rise and fall. Current introduces oxygen into the watery ecosystem in addition to moving food a little lower on the food chain, drawing in everything with gills like a victim to a window in a smoky house fire.

Although flowage locations with current flow are walleye magnets, oxygen and current combine to create a potential for hazardous ice conditions. Ice can be 2 feet thick at the boat ramp or another access point, but only 2 inches -- and unsafe -- out where the ‘eyes are hiding.

In some cases, most notably flowages that transition from flats into old river channels, minnows that walleyes feed on have learned that a tasty meal of invertebrates like bloodworms comes wriggling up off the soft bottom as light levels increase. Minnows ease higher in the water column and move across the flats to feed, and the walleyes will be in pursuit. On a deeply stained flowage, this soft parade is often most pronounced on the sunniest of winter days, especially when snow is a factor.