Selection for behavioural traits in farm mink

Over a period of 6 years, more than 3000 farm mink were tested for their behavioural response to human contact. Using a simple test (the stick test) five times per generation, the mink were characterized and classified with regard to their response to human contact. Behavioural response that might be caused by genetic factors was found to occur in three lines selected for explorative, fearful, and aggressive temperament. Over six generations, a considerable quantitative difference in behavioural response between the three selection lines developed. Selection for fearful behaviour caused the normal habituation towards man to disappear, and 90% of the mink selected for fearfulness responded consistently with fear to human contact. A less distinct effect was found in mink selected for explorative behaviour at human contact. A possible explanation may be that the basic level of explorative behaviour in the population was relatively high, but also that the test used did not allow for a graduation of the explorative behaviour towards confidence. Apart from the last two generations of mink selected for fear, all lines have shown a pronounced difference in temperament between sexes showing that females were more fearful than males.