Movements, Habitat Selection, and Activity Periods of Northern Pike in Eleven Mile Reservoir, Colorado

Ultrasonic telemetry was used to determine movements, habitat use, and activity patterns of 21 adult northern pike Esox lucius in Eleven Mile Reservoir, Colorado. Individual fish were monitored for periods up to 13 months. Most movements paralleled the shoreline and movements directly across the reservoir were rare, Although northern pike did not occupy distinct home ranges, they preferred the vegetated littoral areas of the reservoir. Aquatic vegetation was the key factor in northern pike habitat selection. Changes in macrophyte distribution, current weather conditions, sex of the fish, and time of year all influenced habitat selection. Northern pike were active approximately 37% of the time, with crepuscular activity peaks during summer and a diurnal peak during winter. Northern pike were most active during April and May and least active during October.