Bisoniana LI. The natural food preferences of the European bison in seasons free of snow cover

Abstract

Field studies in 6 forest associations carried out by the direct obser- vation method and study area method made it possible to define the European bison's food preferences. These animals feed on 137 species of plants, which number includes 27 species of trees and shrubs, 14 species of grasses and sedge, and 96 species of dicotyledonous forbs. Marked preference is shown for the following trees and shrubs — Carpinus betulus, Salix caprea, Fraxinus excelsior and Betula pubescens; Grasses and sedges — Calamagrostis arundinacae, Carex silvatica and Carex hirta; Dicotyledonous forbs — Aegopodium podagraria, Urtica dioica, Ranunculus lanuginosus and Cirsium oleraceum. The following trees are most often stripped of bark: Quercus robur, Carpinus betulus, Fraxinus excelsior and Picea excelsa. Three group of plants eaten by European bison were distinguished i.e. those (1) eaten proportionally to their abundance, (2) especially preferred, but with low abundance, and (3) occuring abundantly but forming a negligible percentage of the European bison's food. The preferences for species exhibited by those animals was traced in relation to type and age of biotype. It was found that European bison most frequently feed on plantations and in Calamagrostio-Quercetum and Tilio-Carpinetum forest associations. The percentage formed by the different groups of plants in the European bison's food was defined as follows: trees and shrubs 33%, grasses and sedges and herb plants 67%.