Distribution
Most of the common tree frog populations in the Netherlands occur on sandy soils in the southern and eastern part of the country, except for one population in the province of Zeeland. The largest populations are present in the Achterhoek region in the province of Gelderland. The adjoining Twente region in the province of Overijssel harbours important populations as well, but they are smaller. Some populations have been (re)introduced, including one established with animals from Croatia.
Status
The common tree frog is listed on the Red List as threatened. It is strictly protected under Dutch legislation, the Bern Convention (Annex ii) and the Habitats Directive (Annex iv). The range of the common tree frog decreased by 87% since 1950 caused by habitat loss and large scale lowering of the water levels. Remaining habitats suffered from fragmentation, causing populations to become isolated, whereas desiccation and overfertilizing led to loss of quality. Locally poor habitat management, introduction of fish or collection of animals for the pet trade are causes of decline or even extinction. National and regional recovery programmes are successful, making populations to increase locally, but the bad quality of the surrounding landscape prevented further extension. The biggest success was gained in the Achterhoek area: the number of occupied kilometre squares rose from 11 in 1985 to 62 in 2006 and the number of calling males increased from 250 in 1991 to 2300 in 2006, calling from 109 water bodies. The creation of ‘base habitats’ consisting of 2-3 hectares of land with at least one ideal, large breeding pond (500-2000 m2) and sufficient land habitat, proved to be very successful. Several base habitats are connected by stepping stones.
Bron
Auteur(s)
Zollinger, R., Stumpel, A.H.P. , Stronks, J.
Publicatie
- Creemers, R.C.M. & J.J.C.W. van Delft 2009. De amfibieën en reptielen van Nederland. Nederlandse Fauna 9. Nationaal Natuurhistorisch Museum Naturalis, KNNV Uitgeverij & European Invertebrate Survey-Nederland, Leiden.