THE EFFECT OF COMMERCIAL TRAPPING ON RABBIT POPULATIONS

The effect, of commercial trapping on two rabbit populations in West Wales, was investigated during 1946 to 1949. On two farms rabbits were caught alive in snares, marked and released just before trapping; the total number of rabbits marked, divided by the fraction of. marked rabbits recovered in the trapped sample gave an estimate of the population before trapping started. Trapping usually removed 3- 40 % of the rabbits present, a proportion compatible with a careful cropping of the population. At one farm, studied for 3 years, the population increased steadily. Breeding was intense from January to June inclusive, and from weight and age distributions it was apparent that in 1948 and 1949 considerable breeding also occurred in autumn. The sex ratio varied around a mean of about 50 %. Data are given on movements, obtained from recapture records of 205 marked animals. They suggest that rabbits probably forage over an area of not mo re than 150 yards in diameter. The records from recaptured marked animals indicate that the mean expectation of life is about 6 months.