Peculiar Pike Diets

Pike are known to be highly piscivorous, feeding on fish that can be surprisingly large. There are times, though, when pike are just as inclined to wolf a bellyful of tiny prey. The latter seems to be keyed to the abundance and availability of these smaller food types.

An earlier study by University of Alberta researchers Lauren Chapman, William Mackay, and Craig Wilkinson revealed some curious results about the food habits of pike in eight lakes in Alberta and the Northwest Territories.6 Overall, pike were primarily fish eaters, but consumption of invertebrates was high during spring. In three lakes, invertebrates (mostly amphipods, but also some mayfly and dragonfly larvae) made up 94 percent of the total number of items eaten. In lakes where invertebrate feeding was high in spring, it declined in summer as fish became a bigger component of the diet.

In-Fisherman staff traveling to Canada have become aware that pike, even big ones, sometimes seem to crave leeches. Particularly in spring, leech-imitators often outfish traditional presentations in far north lakes. Dark skirted jigs tipped with a soft-plastic worm, leech, or other softbait have became a top option. Today, the leech connection is catching on, with fly fishermen using black bunny-strip leeches and other smaller-than-usual offerings.

The pike-leech link was recently reinforced by the work of Paul Venturelli and William Tonn at the University of Alberta.7 They examined pike diets in small lakes of boreal Alberta, where winterkill can reduce or eliminate preyfish. Two reference lakes were dominated by pike and yellow perch. A third lake had been fishless for the previous six years. Pike collected from nearby Piche Lake, which contains a mix of preyfish species, were stocked in the fishless lake.

After being placed in the fishless lake, adult pike focused on energy-rich leeches, while juveniles ate a broader mix of invertebrates. In the two reference lakes, amphipods were the dominant prey, with fish, leeches, and larval caddisflies of secondary importance. The researchers conclude that pike can adapt quickly to a lack of preyfish. Pike growth was slower than at lakes containing preyfish, however.

As certain as fishery science moves forward at the quick-step, so too will research on pike and muskies. Among the most popular gamefish in freshwater and as key components in complex aquatic ecosystems, they deserve to go along for the ride.

Footnotes:

1 Miller, L. M., L. Vallemeyn, and W. Senanen. 2001. Spawning-site and natal-site fidelity by northern pike in a large lake: mark-recapture and genetic evidence. Trans. Am. Fish. Soc. 130:307-316.

2 Bosworth, A., and J. M. Farrell. 2006. Genetic divergence among northern pike from spawning locations in the upper St. Lawrence River. N. Am. J. Fish. Mgmt. 26:676-684.

3 Margenau, T. L. 1994. Evidence of homing of a displaced muskellunge. (Esox masquinongy). J. Freshwater Ecol. 9:253-256.

4 Margenau, T. L. and J. B. Petchenik. 2004. Social aspects of muskellunge management in Wisconsin. N. Am. J. Fish. Mgmt. 24:82-93.

5 Margenau, T. L. 2007. Effects of angling with a single-hook and live bait on muskellunge survival. Envir. Biol. Fish. 79:155-162.

6 Chapman, L. J., W. C. Mackay, and C. W. Wilkinson. 1989. Feeding flexibility in northern pike (Esox lucius): fish versus invertebrate prey. Can. J. Aquat. Sci. 46:666-669.

7 Venturelli, P. A., and W. M. Tonn. 2006. Diet and growth of northern pike in the absence of prey fish: initial consequences for persisting in disturbance-prone lakes. Trans Am. Fish. Soc. 135:1512-1522.