an innate pattern of behavior that recurs on an annual basis. For example, prior to hibernation, which occurs around the same time each year, squirrels might eat more nuts, collect nuts, and store nuts. Similarly, squirrels may emerge from hibernation at the same time each year. When seasonal cues are not present, many animals still continue to use this cycle, which suggests that it is innate.
ANNUAL CYCLE: "The birds flew south for the winter and north for the summer as part of their annual cycle. "