Repeatability of behavioural types significantly declined over time. (a) Pairwise repeatability from the test results (behavioural type test versus behavioural type first test), from two test series conducted on the same day ,,,,,,, 151–200 days , 201–250 days and 732–1201 days apart , respectively. The two low sample sizes of 7 are indicated with white circles, but do not affect the regression line, as the line was fitted weighing by the sample size. (b) Pairwise changes in the test series results over time (behavioural type test minus behavioural type first test, ). Note the maximum time difference between two tests of 1201 days. See the text for the regression line.