Efeitos da urbanização na riqueza e composição de aves no Parque Ecológico de Malhazine e na barreira de Maxaquene, cidade de Maputo

Abstract

Habitat loss has been the main threat to Earth's biological diversity, whether natural or anthropogenic. Human activities such as urbanization generate environmental changes that can cause environmental stress and act as a non-random filter, selecting species better able to survive in modified ecosystems. Birds are effective bioindicators of environmental change and have been used to examine the effects of urbanization on biodiversity. This study aimed to understand the distribution and adaptation patterns of birds in the city of Maputo, focusing on two areas with different levels of urbanization: the Malhazine Ecological Park and the Maxaquene Barrier. For this purpose, vegetation cover data from the past (1960) and present (2020) were used to determine whether there have been changes in vegetation cover. Bird data were collected using the listening point method in each area. Species richness was determined for each area using the nonparametric Chao2 estimator and compared using the Mann-Whitney test at a 5% significance level. The trophic guilds of birds found in both areas were compared. Species similarity between areas was tested using the Jaccard index. The stress hypothesis was tested based on the number of specialist diet species. The results show that the Maxaquene Barrier experienced a reduction in vegetation cover over the years, while the Malhazine Ecological Park experienced the opposite. Significant differences were observed in species richness (U=1054.500; p=0.000000). Eight guilds were recorded in the PEM: Carnivore, Frugivore, Granivore, Insectivore, Insectivore/Granivore, Insectivore/Herbivore, Nectarivore, and Omnivore, and six guilds were recorded in the Maxaquene Barrier, with the exception of Insectivore/Granivore and Insectivore/Herbivore. The Jaccard similarity index showed that there is no similarity between the PEM and the Maxaquene Barrier (J=0.36). Thirty-six specialist species were recorded in the PEM and 14 in the Maxaquene Barrier. These results suggest that although both areas are located in urban areas, the level of urban influence differs between them, generating different levels of stress for bird species that decrease with increasing urbanization. It is recommended that future studies include more study areas to confirm whether the same trend in the results obtained in this study will be observed.(TRADUÇÃO NOSSA)