Influence of Seasonal Vegetation Gradients on Waterbird Species Assemblages in Battoum Marsh, Algeria

This study investigated the seasonal dynamics of waterbird communities and their relationships with wetland vegetation gradients in Battoum Marsh, a semi-humid Mediterranean wetland in northeastern Algeria. Seasonal patterns showed higher abundances of several species in autumn and winter, whereas summer was characterized by a marked decline in diversity. Diversity analyses revealed significant seasonal variation in community structure. Shannon and Simpson indices were significantly lower in summer than in autumn and winter, while species richness and evenness did not differ significantly among seasons, indicating that seasonal changes mainly affected diversity patterns rather than the number of species recorded. Multivariate ordination analyses (PCA, RDA, and CCA) consistently identified vegetation structure as the primary factor shaping waterbird distribution. Emergent vegetation height, floating plant cover, and overall vegetation cover constituted the main environmental gradients influencing species composition. Species strongly associated with dense and structured vegetated habitats included Common Moorhen, Eurasian Coot, Common Scoter, Red-Crested Pochard, and Brent Goose, particularly during autumn, winter, and spring. In contrast, Great Northern Loon, Northern Pintail, Red-necked Grebe, and European Shag were generally linked to open or less vegetated habitats. Overall, these findings demonstrate that vegetation gradients and seasonal dynamics play a central role in structuring waterbird assemblages at Battoum Marsh, highlighting the importance of maintaining vegetation heterogeneity for wetland conservation in northeastern Algeria.