Ecological Isolation in Triturus cristatus and Triturus marmoratus (Amphibia: Salamandridae)

Abstract

A field study has been made in the relatively narrow sympatric zone of Triturus cristatus and T. marmoratus, in the department Mayenne (France). Ecological data have been analysed. In the sympatric area specific preferences appear to exist: ecological isolation has developed in some areas. Typical T. marmoratus areas are hilly and wooded, provided with many terrestrial hiding-places, while forest pools and springs especially serve as spawning sites. T. cristatus areas are flat and open. Comparison with distribution data of 24 years ago shows expansion of T. cristatus at the expense of T. marmoratus, which presumably is true for the whole sympatric zone. The preferences of the species in combination with changes in environment by human intervention explain the detected changes in distribution. Ecological isolation as a phenomenon in the speciation of both species is discussed.

Directionality of pre‐ and post‐breeding migrations of a marbled newt population (Triturus marmoratus): implications for buffer zone management

“…This result converges with other studies using fences (Verell, 1987;Malmgren, 2002) or radiotracking (Jehle and Arntzen, 2000). Large deciduous forests probably constitute the major summer and winter habitat of the marbled newt (Schoorl and Zuiderwijk, 1981;Arntzen and Wallis, 1999).…”

Post‐breeding migrations of newts (Triturus cristatus and T. marmoratus) with contrasting ecological requirements

“…This qualitative assessment is supported by the observation that T. cristatus is currently expanding its range at the expense of T. marmoratus populations, a process probably triggered or accelerated by human-induced changes to the landscape (Arntzen & Wallis, 1991). In particular, the removal of hedgerows would lead to a local decline and extinction of T. marmoratus (Schoorl & Zuiderwijk, 1981;Arntzen & Wallis, 1991).…”

“…Although they breed in ponds conspeci®cally, with no discernible niche differentiation between either adults or larvae, they are largely separated in terms of their occurrence in different landscapes. Triturus marmoratus predominates in forests and hilly terrain with scrub and hedges, whereas T. cristatus predominates in¯at and open areas (Valle Âe, 1959;Schoorl & Zuiderwijk, 1981). This qualitative assessment is supported by the observation that T. cristatus is currently expanding its range at the expense of T. marmoratus populations, a process probably triggered or accelerated by human-induced changes to the landscape (Arntzen & Wallis, 1991).…”

Impacts of artificial drainage on amphibian breeding sites in hemiboreal forests

“…Deeper ditches may be permanent or persist longer than natural depressions (Brooks and Hayashi, 2002), being thus favoured by newts that are more aquatic and have longer breeding seasons (Dolmen, 1983;Griffiths, 1997) than the common toad or Rana species. The avoidance of shallow water bodies by newts has been noticed also in other parts of their range (Schoorl and Zuiderwijk, 1981;Denoël and Ficetola, 2007). In addition, amphibians could use ditches for moving between different landscapes (Mazerolle, 2004) or for hibernation (Elmberg, 2008).…”