Aggression, hunger, and curiosity of ranch mink (Mustela vison) were examined. The animals were divided into socialized animals (those visually isolated at 1 year of age) and unsocialized animals (those visually isolated at 10 weeks of age).Aggression was measured by placing two mink in a special cage and measuring the time until a fight or confrontation occurred. The effects of 0, 24, and 48 hours of food deprivation were measured in summer, fall, and winter. The number of trips made by each mink up a vertical cage to get food was used as an indicator of hunger. Levels of curiosity were determined by measuring the speed and pattern of exploration of a novel open-field situation. The breeding behaviors of experienced and inexperienced male mink were compared.Aggression in mink consisted of at least two offensive threats and, as in other animals, fighting was ritualized to a great extent. All young mink showed some adult aggressive patterns by 20 weeks of age. Aggression in males reached a peak at breeding season (March) and declined throughout the summer and fall, to a low point in November. Socialized males had lower aggressive levels than unsocialized males. Aggression in female mink reached a peak after the breeding season and declined to a low in winter. These cycles were likely caused by gonadal hormones in males and hormones from the corpora lutea in females.Both consumption and storage of food must be considered in determining hunger in mink. Hunger varied inversely with environmental temperature, reaching a peak in the winter and a low point in the summer. Immature animals had lower hunger drives than adult animals. Changes in body weights of mink centered around the breeding season.Curiosity decreased from summer to fall as did aggression. Unsocialized males had higher levels of curiosity than socialized males and females. Immature mink showed incomplete exploratory behavior and had lower curiosity scores than adult animals.
