Distribution and Present Numbers of the Tree Frog Hyla Arborea in Zealand Flanders, The Netherlands (Amphibia, Hylidae)

A distribution survey of Hyla arborea has been carried out in the western part of Zealand Flanders over a period of six years. Additional data on the eastern part and the neighbouring Belgian area have been collected. The relationship between the maximum number of males calling on one evening/night and the estimate of their population size is a suitable basis to predict the total number of males in other pools during a season. Methodological aspects of the fieldwork are discussed. Great fluctuations in presence and activity of the Tree Frog illustrate the need for longterm surveys. Hyla arbore... Mehr ...