Wildlife

Northern Pike (Esox lucius):

Northern pike are found throughout the northern hemisphere. Northern pike inhabit many shallow weedy ponds and lakes throughout the Togiak National Wildlife Refuge, primarily in the eastern portion of the refuge.

Northern pike have an elongated body shape with the dorsal and anal fins toward the rear of the body. Their large eyes are on the dorsal side of the elongated flattened snout. The mouth has many large teeth that the northern pike uses to hold its prey. The body color is greenish to brownish, with many yellowish irregular spots and a yellow to white belly. Fins can have a reddish to brown tint with dark stripes. Alaska's northern pike are known to attain weights up to 15 lbs in some interior areas.

Adult northern pike are piscivorous. Sticklebacks, blackfish, and many juvenile fish comprise the primary diet of adults. Northern pike are known to be cannibalistic, feeding on smaller northern pike. Additionally, when available, small mammals, ducklings, and amphibians can comprise a large seasonal component of the diet. The northern pike makes a living by lying in wait in the weeds for prey to swim by, then with a powerful thrust from its tail it shoots from its hiding place. The prey is sucked in, then grasped in the mid-body by the northern pike's sharp teeth. The prey is turned around in the mouth and swallowed head first, thus making a smooth entry into the stomach.

With the onset of spring, adult northern pike move from their deep water winter retreats to the shallow margins of the lakes and the ponds, sometimes traveling under ice. Pike are known to return to the same spawning grounds year after year. They spawn in the early spring during the daylight hours, when the water temperatures in the shallow areas of the lakes and ponds are between 6^oC to 9^oC. The spawning grounds tend to be shallow quiet areas with weed-covered mud bottoms. A male courts a female by nudging her head region with his snout. Through a series of thrusting movements, the male entices the female to expel her eggs. Simultaneously, he ejects his milt to fertilize the eggs. The fertilized eggs then settle to the weedy bottom and hatch in about two to five weeks, depending on the water temperature. Newly hatched northern pike attach to weeds and live off their yolk sac while their mouths develop. Initially the young feed on zooplankton, but soon graduate to insects, and finally fish and other larger prey. The switch to a high energy fish diet enables the juvenile northern pike to grow quickly for the first year. Northern pike are predators and have been known to consume other northern pike that are 70 % of their own body lengths. Northern pike mature when they are approximately 3-4 years of age.

For more information:

Morrow, James E. 1980. The freshwater fishes of Alaska. Alaska Northwest Publishing Company. Anchorage Alaska.

Or, visit the Alaska Department of Fish and Game's wildlife notebook pages.

Last updated: July 24, 2008