A Debreceni Déri Múzeum Évkönyve 1994 (Debrecen, 1996)

Természettudomány - Juhász Lajos–Vas András: The Population Dynamics and Diversity in artifical Nextboxes in Debrecen-Nagycsere

Lajos Juhász—András Vas THE POPULATION DYNAMICS AND DIVERSITY IN ARTIFICAL NESTBOXES IN DEBRECEN-NAGYCSERE Our research program indued the investigation of the breeding population and nesting fenology entities of a bird community breeding in artifical nestboxes in a wood at Debrecen-Nagycsere. We followed up the changes in these values for four consecutive years. The most important group of nesting bird communities in hard-wood forest to be that of cavity nesting birds. The patriation of these species in nestboxes is an important task both from the point of view of nature conservation and ornithological research. In the course of four breeding seasons 8 bird species and a protected small mammal, the Common or Hasel Dormous (Muscardinius avellanarius) occupied the nestboxes. The majority of the breeding pairs were Great Tits (Parus major) 48—73%. Blue Tits (Parus caeruleus) were also typical breeding birds with a close to steady frequency value (12—13%). Four other species occurred in the nestboxes with fluctuating frequency values: Starling (Sturnus vulgaris) 12—23%, Marsh Tit (Parus palustris) 2— 13%, Collared Flycatcher (Ficedula albicollis) 4—15%, Robin (Erithacus rubecula) 3%. Two new species appeared in 1993, Tree Sparrow (Passer montanus) 4% and Redstart (Phoenicurus phoenicurus) 2%. A second nesting was detected only in the case of Great Tits and Collared Flycatchers. Almost 60% of the nestboxes were occupied by nesting birds and the Common or Hasel Dormous appeared also in high numbers. The offspring of nesting birds in nestbox communities is important for the preservation of the species and further increases the biological and nature conservancy values of hard-wood forests. Nestboxes maintain a high population diversity in the most important nesting communities i.e. the cavity nesting birds of hard-wood forests. Nestboxes contribute to the preservation of biodiversity by balancing the negative fluctuations in population dynamics of these birds. 24