Structure and dynamics of bird assemblages is driven by many processes such as interspecific competition, intraspecific competition, predation, parasitism, stochastic events, etc operating on varying temporal and spatial scales.
Our main research focus is on temporal and spatial patterns of bird assemblages in the Western Carpathians. Since 1990, a team of Slovak researchers set census plots in the representative primeval and natural forest in all vegetation belts from lowland and floodplain forest up to dwarf pine communities. Bird assemblages were censused by the territory mapping method from two up to 20 years. At the present time, we are working on synthetic studies describing elevational patterns of species richness, diversity, density, evenness and guilds. In addition, we analyses species responses to floristic and structural parameters of forest stands that effect habitat selection.
A primeval beech-fir forest in the Šrámkova National Nature Reserve was selected as a model study site to analyze foraging guild structure, foraging ecology of forest birds, tree species preferences of birds for foraging and bird assemblage dynamics. We determined guild structure based on real random point observation of foraging birds and determined functional structure of the assemblage. Vertical allocation of foraging substrates and spatial tree morphology were determined as the main factors forming guild organization. We found out that rare tree species such sycamore and elm are strongly favoured for foraging by many bird species, while several dominant tree species are avoided. We census this reserve annually since 1997 by the territory mapping method with the objective to describe bird population and assemblage temporal variability and evaluated factors that causes variations.
Finally, we also partly focus on macro ecological studies of bird assemblages on global scale. We compared guilds structure patterns of bird assemblages from three model study site on three continents and searched for factors that might drive convergence. Currently, we are trying to answer whether compensatory dynamics is the main driver of bird assemblage dynamics by null modelling based on meta-analyses of long-term studies of bird assemblages worldwide.
Forest management influences the composition and structure of animal assemblages, mainly by changing their habitats. Understanding the key principles of organization of bird assemblages in natural and man-made communities is a principal step toward modern forestry practices that try to preserve organismic diversity. The results of our research are considered to be essential for effective conservation and management strategies, as well as for implementation of sustainable forest management principles.
ADAMÍK, P. & M. KORŇAN. 2004. Foraging ecology of two bark foraging passerine birds in an old-growth temperate forest. Ornis Fennica 81: 13–22.
KORŇAN, M. & P. ADAMÍK. 2007. Foraging guild structure within a primeval mixed forest bird assemblage: a comparison of two concepts. Community Ecology 8: 133–149.
LEŠO P. & R. KROPIL 2007: A comparison of three different approaches for the classification of bird foraging guilds: an effect of leaf phenophase. Folia Zoologica 56: 51–70.
KORŇAN, M, R.T. HOLMES, H.F. RECHER, P. ADAMÍK & R. KROPIL. 2013. Convergence in foraging guild structure of forest breeding bird assemblages across three continents is related to habitat structure and foraging opportunities. Community Ecology 14: 89–100.
KORŇAN, M. 2013. Breeding bird assemblage dynamics in a primaeval temperate mixed forest in the Western Carpathians (Slovakia): support for pluralistic community concept. Ornis Fennica 90: 151–177.