Tree frog: trends in numbers
The tree frog is endangered because its habitats are becoming less suitable and more fragmented. The implementation of conservation measures will allow the species to recover and to increase in numbers fairly quickly.
Trends
Until the early 1950s the tree frog used to be fairly common on the higher-lying sandy soils, but since 1986 it has been found in only a small part of its former area of distribution. In Zeeland, Noord-Brabant and Limburg many habitats have disappeared. The species is now concentrated in the Achterhoek, Twente and western Zeeuws-Vlaanderen. The tree frog protection plan was published in 2001. It aims to maintain a sustainable population of the species in the Netherlands.
Causes
The decline is attributable to changes in agriculture, to the effects of water draw-down and acidification, to the release of fish in water where the frogs breed, to the terrestrialisation of pools and to fragmentation of the surviving habitats. In the Achterhoek a number of pools has been restored and new pools and suitable areas have been created; this has led to a sharp increase in tree frog locally.
The tree frog is on the Red List of amphibians and reptiles in the Netherlands
Technical note
The map shows the differences between the distribution in 1986-2001 and in 1950-1985.
References
- RAVON-Werkgroep Monitoring (2002). Meetnet Amfibieën. Mededelingen nr. 9.
- LNV (2001). Beschermingsplan Boomkikker 2001-2005. Directie Natuurbeheer. Ministerie van Landbouw, Natuurbeheer en Visserij. Wageningen.
- Bergmans, W. en A. Zuiderwijk (1986). Atlas van de Nederlandse Amfibieën en Reptielen en hun bedreiging. Vijfde Herpetogeografisch Verslag. KNNV. Hoogwoud.
