Understanding Spring Walleye Migrations
June 02, 2011
Walleyes spawn in spring, but spring may arrive in February in Mississippi, March in Kentucky, April in the Midwest, and June in the Far North. And you can't bet on those dates. Biologists have found walleyes laying eggs in Red Lake, Minnesota, and Escanaba Lake, Wisconsin, as early as April 5 and as late as May 7. Water temperature plays a key role. Even here, ideal temperatures vary by latitude. Southern walleyes prefer spawning temperatures between 48°F and 50°F, while their Yankee cousins and Canadian counterparts favor temperatures between 44°F and 48°F.
In the extreme Far North, if those ideal conditions don't arrive early enough, walleyes absorb their eggs and forego spawning. In the South, on the other hand, walleyes spawn successfully based on what scientists call the chill temperature hypothesis. In order for their eggs to develop properly, they need to spend a portion of winter in water temperatures that dip below 50°F.
Spring Walleye Migrations
When walleye migrations begin for spawning, we find as much variation and dissimilarity in their movement patterns as during the rest of the year, although the norm probably is different than most anglers suspect. "Mature members of all self-propagating walleye populations, whether stream-spawning or lake-spawning, migrate from overwintering grounds to spawning grounds in spring," says Dr. Peter Colby, former head of the walleye research program of the Ontario Ministry of Natural Resources. "But the fish often aren't the long-distance runners many anglers believe them to be."
He confirms what most walleye anglers already know: Stream spawners migrate into creeks and rivers to spawn on rock and gravel substrates. Lake spawners move inshore to spawn on shallow, windswept rock and cobble shoals. In many waters both types of walleyes coexist, a way to ensure effective spawning.
Colby says that tagging studies indicate that most walleye populations move only a short distance. "Even in Lake Superior and Georgian Bay," he says, "a majority of spawners move no farther than three miles from their spawning grounds. Presumably, a migration of similar magnitude is undertaken to return to the spawning grounds the following spring, since evidence now suggests that mature walleyes tend to return to the same spawning grounds year after year."
He calls this repetitive migration. He points to studies where walleyes were transferred upstream in river impoundments, only to move back downstream, past dams and other barriers, to their original locations. He acknowledges that some intermingling occurs, especially in lakes and reservoirs where spawning sites lie close to one another.
Learned Spring Patterns
Minnesota biologists Donald Olsen and Dennis Schupp, and Ontario biologist Val Macins, have reinforced the research Colby draws on. These scientists suggest that the ability to home in to specific spring spawning sites is an adult learned behavior, an action influenced by the water's physical layout — size, shape, bottom contours, and locations of suitable lake and river spawning areas. By roaming, walleyes become familiar with the best spawning areas.
Some waters, such as the Rainy River at the south end of Lake of the Woods, the Red River at the bottom of Lake Winnipeg, the Thames River in Lake St. Clair and Lake Erie's western basin are major spawning draws. In other waters such as on Canadian Shield lakes, many smaller spawning sites exist and spawners are more spread out.
Olsen, Schupp, and Macins believe that the more often a walleye returns to a specific spawning shoal, the more permanent the route and site become. Walleyes must learn where to go in spring. After hatching, walleye fry are at the mercy of wind and river currents; they are dispersed throughout the lake or reservoir. Their return is different from the salmon-spawning rite, which plays out as a struggle to return to a birthplace to spawn before dying. Salmon fry remain in a natal stream for a year or more, becoming imprinted with the smell and taste of their home waters before leaving for the ocean.
Walleyes develop a homing instinct to a spawning area they chose as adults. This homing mechanism, according to the three biologists, is strongest in walleyes with short migrations between summer and winter feeding areas and spawning sites. In their words, "spawning migrations from home feeding areas likely are to the nearest spawning site, even though migrations of great distances apparently occur (in portions of some populations)."
More interesting still, the scientists suggest that the destination of a first-time spawning walleye probably is a chance occurrence. First-time spawners travel with adults — like migrating geese in fall — following them to spawning sites. Regardless of how they find spawning sites, walleyes appear to choose them and then home to them with greater fidelity each year of their lives.
This suggests that in lakes and reservoirs peppered with spawning shoals, the best fishing for larger walleyes likely is adjacent to those sites that are the best summer and winter areas for big fish. Those spawning sites may not be the largest spawning areas in terms of physical size or numbers of fish they host; but on a micro basis, they're the best.
Popular opening-day spots well known for producing numbers of eating-size walleyes, meanwhile, may or may not harbor many large fish. Indeed, these sites probably are subject to fluctuations in the number of walleyes that use them. Olsen, Schupp, and Macins suggest that "If homing is strengthened by repeated migrations, populations comprised of a large proportion of older fish, rather than heavily exploited populations of younger fish, would display stronger homing tendencies."
Still, this can change over time, especially when enlightened management rules afford more protection to fish entering the egg-laying stage of their lives. Then, as more walleyes move into the adult ranks, Colby's reinforced homing mechanism kicks in and the age of the fish on a particular spawning location increases.
Older walleyes appear to be smarter than younger fish, which is hardly a surprise. In Lake Huron's giant Georgian Bay, researchers found that the proportion of tagged river-spawning walleyes was greatest in years when river flows were at their lowest levels. This suggests that the larger fish (almost always females) are better able to remember details.
Larger walleyes also move from spawning areas in a hurry — much faster than most anglers think. "We got into a bunch of small males," is the usual opening-day refrain from frustrated walleye anglers. "The bigger fish are recuperating and refuse to bite." But according to Colby, smaller male walleyes predominate in the spring catch because males outnumber females on the spawning grounds. Males mature at least a year earlier than females, adding at least one extra year-class of them on the shoals.
Colby also says that larger female walleyes quickly vacate spawning areas in search of a deep-water refuge. They head for deeper regions, especially if soft-rayed forage like ciscoes and smelt are available. It isn't that they just quit feeding.
Younger, smaller walleyes, both male and female, often forage on perch. Perch tend to stay shallow, so smaller walleyes stay shallow, too. This isn't to suggest that large walleyes don't eat perch. They certainly do, especially in emerging weedgrowth during the Presummer and Summer Peak periods.
Small walleyes eat perch (and shiners) because these baitfish are more abundant, not just because walleyes prefer them, Colby explains. As walleyes grow bigger, however, they switch from what is most abundant to what they prefer: Soft-rayed forage like deeper-dwelling herring and smelt. And walleyes also function metabolically more effectively in the depths.
Across the board, spring walleye populations remain available, not only to groups of traditional walleye anglers, but also to anglers in areas like middle Dixie, where fishing for them is starting to catch on. The first factor in fishing is to understand the fish and how it relates to its environment. Thus we begin our seasonal quest to catch this big-eyed perch that can be so illusive at times.
In-Fisherman Field Editor Gord Pyzer, Kenora, Ontario, is a former resource manager who has been writing for In'‘Fisherman publications for two decades.