Temporal Patterns of Wetland-Associated Bird Assemblages in Altered Wetlands in Turkey

Abstract

A loss of wetlands, one of the highly sensitive ecosystems, necessitates the monitoring and assessment of wildlife population trends for the continuity and sustainable management of species. The goal of our study was to evaluate temporal changes in wetland-associated bird composition by conducting monthly counts during December 2006 - November 2007 and March 2015 - February 2016 in Efteni Lake, Duzce, Turkey. This lake has been exposed to structural change including shoreline length, area and depth for the last 50 years. Wetland-associated bird richness decreased, and abundance increased during the decade, but this change was not significant except for two species with an increased population, ferruginous duck Aythya nyroca and great crested grebe Podiceps cristatus. Cluster analyses resulted in two groups: the breeding season from April to September, and the non-breeding season from October to March. The most numerous species were observed mostly during the non-breeding season. Some guilds, including diving carnivores, omnivores, shoreline omnivores and herbivores species were more prevalent during the non-breeding season. The insectivores had higher population densities during the breeding season. Thus, wetland-associated bird abundance during the non-breeding season was higher than during the breeding season, although species richness was the opposite. The planned restoration of habitats of Efteni Lake should have a positive impact on birds by creating more space available to them. Our result should help to better understand the impact of habitat changes on waterbird assemblages. Long-term monitoring of Efteni Lake will be useful for the wetland-associated avian community, and for other animal and plant communities.