Current Trends in Natural Sciences Vol. 6, Issue 12, pp. 259266, 2017 Current Trends in Natural Sciences (online) Current Trends in Natural Sciences (CDRom) ISSN: 2284953X ISSN: 22849521 ISSNL: 22849521 ISSNL: 22849521 http://www.natsci.upit.ro *Corresponding author, Email address: denisa_conete@yahoo.com 259 ECOLOGICAL RESEARCH ON AVIFAUNA FROM THE SITE NATURE 2000 ROSPA0062 – “LACURILE DE ACUMULARE DE PE ARGE”. THE SEROTINAL SEASON Maria Denisa Conete 1,* 1 University of Pite7ti, Faculty of Sciences, Physical Education and Informatics, Department of Natural Sciences, Pite7ti, Romania, 1 Târgul din Vale, 110040 Pite7ti, Romania Abstract The present paper provides the results of the ecological research conducted on the avifauna of the reservoirs located in the middle valley of the Arges River during the serotinal season. The serotinal season was one of the richest in species (we identified 169 species belonging to 15 orders, 45 families and 99 genera) as it is the season when the autumn agglomeration specific to migration is formed; 66 species are dependent on wetlands. We also performed an analysis of the avifauna based on ecological indices ((I R, constancy, dominancy, the Dzuba index of ecological significance, etc.). The Anseriformes, Passeriformes and Charadriiformes were overdominant. According to the dominance index and the Dzuba index of ecological significance, there were 5 characteristic species (eudominant and dominant): Anas platyrhynchos, Aythya ferina, Fulica atra, Phalacrocorax carbo and Larus ridibundus. The high number of subrecedent species (122 species) emphasizes a high fluctuation of bird species in the area under research, especially on the Gole0ti Lake, also due to the fact that these lakes are on the route of the Rucăr3Bran migration corridor. We also notice in the serotinal season (as well as in the hiemal and prevernal seasons) the great importance of the reservoirs for birds. These reservoirs are immense stretches of water, whose value should be considered in correlation with their large valleys, where there are various agricultural crops and large areas of forest. This high habitat heterogeneity explains the presence of a high number of bird species during migration, even though there is a strong anthropogenic influence in the area under research. 33 species are enlisted in Annex 1 of the Birds Directive. Keywords: Arge0 River, birds, serotinal season. 1. INTRODUCTION The Arge7 hydrographyc basin is located in the SSE of Romania and is delimited by the Făgăra7 Mountains in the north and the Danube River whose tributary it is at OlteniŃa in the south (figure 1) (Barco and Nedelcu, 1974). A series of reservoirs has been built on its stream after 1960 for the production of electric energy, as a water supply source for the cities and industrial objectives in the area, and the irrigation of the surrounding agricultural terrains. Over the time, the newly created lakes (Vâlcele, Budeasa, Bascov, Pite7ti, Gole7ti) have become the preferred nesting areas for certain bird species, many of them coming here for wintering or just passing by during their passage, as it is a well known fact that the middle basin of the Arge7 River is an extension of the Rucăr – Bran Corridor, one of the corridors used by migrating birds to get across the Carpathians (Mătie7, 1969; Munteanu and Mătie7, 1983; Gava, 1997; Conete, 2011; Conete, 2014; Conete, 2015, etc).