Statut et écologie de l’avifaune urbaine de la région de Ghardaia (Sahara Septentrional)

Abstract

This thesis explores the diversity and composition of bird communities in the city of Ghardaïa, located in the northern Algerian Sahara, between September 2022 and September 2024. The study aims to assess the influence of the urbanization gradient and vegetation structure on species richness, abundance, and community composition of avian species. Data were collected from listening points distributed across three contrasting habitat types: urban, semi-urban, and agricultural. Diversity indices (Shannon–Wiener, Margalef, Simpson) were calculated, and statistical analyses (one-way ANOVA) as well as multivariate analyses (NMDS, PERMANOVA) were used to test differences between habitats. A total of 44 species belonging to 10 orders and 23 families were recorded. Maximum diversity values were observed in semi-urban and agricultural habitats (H' = 3.82; Margalef = 3.66; Simpson = 0.92). Differences in richness, number of families, and abundance between habitats proved to be statistically significant. The results show that vegetation cover and floristic richness exert a positive and significant effect on avian richness, abundance, and diversity. Multivariate analyses highlight a clear structuring of bird assemblages according to the degree of urbanization. The study highlights the combined impact of vegetation and urbanization on the distribution and richness of bird species. It demonstrates that preserving avian diversity in the Saharan environment requires urban planning that integrates habitat conservation, ecological management of green spaces, and sustainable urban development in the Ghardaïa region.