Spawn string counts (female population) increased from 15 to 43, with a maximum number of 48 in 1989 (see also Buckley & Beebee 2004). The Herpetological Journal, 3, 99-110.Ī before-and-after study in 1972–1991 of ponds on heathland in Hampshire, UK (Banks, Beebee & Denton 1993) found that pond restoration by deepening, along with other interventions, tripled a natterjack toad Bufo calamita population. (1993) A six year study on the populations dynamics of the crested newt ( Triturus cristatus) following the colonisation of a newly created pond. Newts were monitored in 1979–1984 and in 1992 by torching the shallow part of the pond from dusk to midnight and dip-netting. 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.
Before enlargement, the shallow pond (30 cm) supported a breeding population of natterjack toads Bufo calamita, but not great crested newts. The juvenile cohort was estimated at 300 individuals in 1980, but zero by 1984. Variation in the adult population was largely due to variation in juvenile recruitment. However, by 1992 the population was estimated at 55 adults. The population increased to 346 adults within five years, but decreased to 16 newts two years later. Newts were recorded in the pond the year after enlargement.
Supporting evidence from individual studiesĪ 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.
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