Individual study: Pond enlargement resulted in a rapid colonisation and fast initial population increase followed by a dramatic decline of great crested newts in France
Arntzen J.W. & Teunis S.F.M. (1993) A six year study on the populations dynamics of the crested newt (Triturus cristatus) following the colonisation of a newly created pond. Herpetological Journal, 3, 99-110
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Deepen, de-silt or re-profile ponds
A before-and-after study in 1977–1992 of a pond in an abandoned sand-quarry in northwestern France (Arntzen & Teunis 1993) found that pond enlargement for great crested newts Triturus cristatus resulted in rapid colonization and fast initial population increase, followed by a dramatic decline. Newts were recorded in the pond the year after enlargement. The population increased to 346 adults within five years, but decreased to 16 newts two years later. However, by 1992 the population was estimated at 55 adults. Variation in the adult population was largely due to variation in juvenile recruitment. The juvenile cohort was estimated at 300 individuals in 1980, but zero by 1984. Juvenile survival varied from 7 to 45%. Before enlargement, the shallow pond (30 cm) supported a breeding population of natterjack toads Bufo calamita, but not great crested newts. In summer 1977, it was enlarged by 7 x 20 m, approximately doubling its area, and to a maximum depth of at least 1.2 m. Newts were monitored in 1979–1984 and in 1992 by torching the shallow part of the pond from dusk to midnight and dip-netting.
(Summarised by Rebecca K Smith)