Distribution and Habitat of Rana Esculenta Complex in the Netherlands

Abstract

In various waters distributed widely over the Netherlands green frogs were collected in order to get a picture of the distribution and habitat of the different forms belonging to Rana esculenta complex. The distinction between these forms-lessonae, esculenta and ridibunda-was based on biometrical and serological characteristics. Apart from the albumin patterns which were already known for the Netherlands-A (lessonae), AB (esculenta) and B (ridibunda)-a new type was found, viz. albumin pattern BC belonging to ridibunda. Especially many frogs with albumin pattern AB were misclassified (i.e. allotted to another albumin class) by means of discriminant analysis, on the basis of their biometrical characteristics. This cannot be explained at the moment. Ridibunda was mainly found in areas abounding in water lying in the northern half of the country, but the type and size of the water seems to be of minor importance. Lessonae lives in smaller, often isolated waters, probably in most parts of the country. Esculenta can be found in all sorts of waters throughout the country, often together with one, seldom both, of the other forms.