The aim of this diploma thesis is to show potential habitat models for woodpeckers in the Nationalpark Kalkalpen in Upper Austria.These optimal habitats, vicarious for the Three-toed Woodpecker and the Black Woodpecker, have been developed with a Geographic Information System (GIS) and reconsidered with real woodpecker dedections in the investigation area.The basis for the model construction has been established upon data research of the six current woodpecker occurrences in the Nationalpark and a characterisation and evaluation of the limiting habitat factors by literature research, additionally to the knowledge of an expert.The results of a raw data research in the nationalpark data pool and the ZOBODAT (Zoological Botanical Database) prove 1435 woodpecker dedections from 1982 ? 2008. According to these results, the most frequent observed woodpecker taxon in the nationalpark is the Black Woodpecker with 658 proofs, followed by the Three-toed Woodpecker (n=250), the Grey-headed Woodpecker (n=195), the Great Spotted Woodpecker (n=155) and the White-backed Woodpecker with 124 proofs. The Green Woodpecker (n=51) plays a subordinated role in the Nationalpark area. The habitat model supplies a forecast quality of 94,34% with altogether 107 Three-toed Woodpecker proofs as potential breeding and foraging habitats in the Nationalpark area. In case of the Black Woodpecker with 362 proofs in potential breeding and foraging areas the modell delivers a forecast quality of 91,99%.24% of the Nationalpark surface can be allocated as potential optimal habitats, thus areas with highest breeding respectively survival success (habitat class 9-10) for the Three-toed Woodpecker. 58% of the nationalpark surface are allocated as potential Black Woodpecker habitats with high to highest breeding respectively survival success. Including the usable but suboptimal habitats, the potential dispersion of the Black Woodpecker increases up to 16.700 hectares (80%) of the Nationalpark surface.