Ábrahám Levente (szerk.): Válogatott tanulmányok VI. - Natura Somogyiensis 19. (Kaposvár, 2010)

KOVÁCS GY., WINKLER D. & FARAGÓ S.: A kárókatona fészekalj és tojásméret vizsgálata a Kis-Balatonon és a Nagyberekben

KOVÁCS GY., NAGY Á. & WINKLER D.: WATERFOWL POPULATION SURVEY 265 Fig. 1: Survey points around the Marcali reservoir The attributes of bird communities are presented via comparison of number of individuals, density, species richness, ecological composition, dominance structure, constancy, Shannon diversity index (H = pi In pi) and equitability (J = H / In S - where S is species richness). Community structure comparison between different seasons was estimated using single linkage cluster analysis based on Jaccard's similarity index. Further comparison was made by Hutcheson's diversity t-test (HUTCHESON 1970) and by Rényi diversity profiles (

TÓTHMÉRÉSZ 1997). Rényi diversity profiles allow for partial ranking of ecological communities based on diversity: a community of higher diversity than a second community will have a diversity profile that is consistently above the profile of the second community. In case the diversity profiles cross each other, the communities are not comparable. Linear regression analysis was used to relate bird species ricnhess and number of individuals to the water level. All statistical calculations and tests were prepared using PAST software (HAMMER et al. 2001).