Wintering Behaviour and Spatial Ecology of Eurasian Wigeon Anas Penelope in a Coastal Mediterranean Wetland Complex (Guerbes-Sanhadja) of Northeastern Algeria

Abstract

As rare and threatened species, ecological information about common waterbirds is needed to assess priorities for wetland management. In this study, we attempt to provide information about the spatial ecology and wintering behaviour of one of the most common species of the coastal Mediterranean wetland complex of northeastern Algeria, the Eurasian Wigeon Anas penelope. Over the three winters of the study the maximum number of recorded Eurasian Wigeon across all sites rose from 1,096 in 2010/11 to 1,397 in 2012/13. This represents a 27% increase over three years in the Guerbes-Sanhadja region. Among these wetland complex sites abundance varied markedly during the three wintering periods of study, being highest in Garaet Hadj-Tahar and Garaet Beni Mhamed (ranging from 300–700 individuals), and lowest in the remaining sites, which never exceeded 150 individuals. Bird abundance often peaked in January of each year and decreased as winter progressed. Wigeon have similar patterns of migration phenology among years at Garaet Hadj-Tahar and Garaet Beni Mhamed. At the remaining sites, they exhibited a different pattern. The multiple regression analysis for all seasons showed a marginally significant correlation between Wigeon abundance changes and three environmental variables of the wetland complex exclusively in the spring seasons (depth, vegetation and temporariness). A roosting area is identified as a functional role of the Guerbes-Sanhadja wetland complex for this anatid, since they spent all of the daytime sleeping, swimming (ranged from 30 to 40%), and resting (from 15 to 25%) in all winters. Despite their semi-permanent and unprotected status (apart from only three sites), these patched wetlands provide suitable conditions for this sensitive species, and therefore should receive the attention of wetland management.