The population dynamics of the crested newt Triturus cristatus at a pond in southern England

The population dynamics of a population of crested newts Triturus cristatus were studied in 1983 at a pond in southern England, Three length classes of individuals were distinguished. Adult newts between 67 and 84 mm snout-vent length migrated to the pond in spring, on days when the temperature approached 5°C. Males tended to arrive earlier than females and to remain in the pond for longer. A second period of immigration of smaller adults, between 57 and 70 mm in length, took place in the autumn; these newts overwintered in the water and may have been about to breed for the first time. Juvenile newts measuring between 40 and 51 mm in length also visited the pond during the spring and summer. Immigrant male and juvenile crested newts were significantly higher in weight than emigrants: there was no significant difference between the weights of immigrating and emigrating females.