Though not documented, this shift is likely due to food availability. While prey is plentiful, pike remain. But when a group of large predators has either cropped baitfish numbers or caused schools to leave the area, pike abandon this feeding ground and move elsewhere for more fruitful hunting.

Spawn-time Movements

Recent research has focused on spawning locations of pike, because shoreline development and loss of wetland habitat threaten areas essential for reproduction. Tagging studies have indicated that some pike return to spawning areas in consecutive years, emphasizing the need for protection of marsh habitat.

Though they’re used by adult pike only in spring and may become dry in summer, wetlands swell with late winter snowmelt and spring rains, drawing adults. Big pike thrash and chase about in water just a foot deep, finally depositing fertilized eggs on the stalks of emergent grasses or submerged terrestrial vegetation.

Biologists define two types of fidelity to spawning locations: Spawning site fidelity, when individuals return to the same spawning grounds in subsequent seasons, regardless of where they were born; and natal site fidelity, when fish return to spawn in the location of their birth. Natal site fidelity tends to result in reproductive isolation between spawning populations that may mingle at other times of year.

Recent advances in genetics have helped us to understand the homing of pike to spawning sites. Ability to analyze minute variations in DNA among fish has allowed researchers to determine how closely different populations are related. At Minnesota’s Lake Kabetogama, Dr. Loren Miller and colleagues tagged pike and genetically examined groups that spawned at two of the three key locations in this 26,000-acre lake.1

They found that adults tended to return to the same spawning location in subsequent years, though a few fish did spawn at the alternate location, which was a little more than 9 miles away. The percentage of straying from the Tom Cod Creek site to Daley Brook was 1 percent, while those straying to Tom Cod Creek from Daley Brook was 5 percent.

DNA analysis showed that this level of spawning segregation yielded populations with significant genetic differences. They concluded that pike showed both spawning site and natal site fidelity. This result adds to the growing body of evidence that populations of many landlocked freshwater species, including smallmouth bass, walleye, and yellow perch, may exhibit both spawning and natal site fidelity.

A follow-up study done on the Thousand Islands area of the St. Lawrence River found, however, that pike populations spawning in nearby marshes tend to be genetically closer than those spawning in more widespread locations, and that fish stray more when alternative spawning sites are close.2

Tagging studies have shown that muskies also tend to return to previous spawning locations in some waters, though genetic studies have not yet confirmed homing to natal sites. Muskies caught from an area and moved to another also have been able to return to their former area. The most dramatic instance was documented by biologist Terry Margenau, who followed a radio-tagged fish after it was caught on a lure in Tomahawk Lake in Wisconsin and displaced to Mid Lake, about 5 miles away through a winding channel.3 After recuperating in a weedbed for about three days, she departed and, after wandering a bit, returned near her point of capture just three days later.

Muskie Hooking Mortality

Developing trophy fisheries often requires strict harvest regulations such as high minimum-length limits or slot-length limits. Trophy muskie fisheries often are managed with high minimum-length limits. Moreover, a large proportion of muskie anglers practices catch-and-release of larger legal-sized fish to help sustain numbers of big fish. Hooking mortality can potentially hinder development of trophy fisheries, however.