Investigation of ecological structure (abundance, evenness, dominance, similarity and diversity) of Golestan Province birds in a period of five years (2011-16)

Birds are the only organisms that, because of flight ability, have a wide range of distribution. Changes in their composition, diversity and density can indicate changes in the environment. This study was done for the first time with the aims of identification of bird species and their diversity, and calculation of different ecological indices in a period of five years (2011-16) in 22 sampling sites in Golestan Province, located in Caspian Sea, Iran. From 123 identified bird species belonging to 27 bird families, 6 species have been listed in the International Union for Conservation of Nature. The highest number of birds belongs to the order of Anatidea, but in terms of individual bird species, the Common Coot, Mallard and Greater Flamingo had the greatest numbers. Ecological indices showed that the highest diversity and evenness of species occurred in 2012; during the last year of the study, not only did the number of species decrease, but also, all of the diversity indices declined, while the dominant index significantly increased. The results of this study are a warning for enthusiasts and lovers of environment conservation as well as experts and managers of this field of study, and the need for conservation of these areas is emphasized.