Vegetation Diversity as a Driver of Avian Richness and Seasonality in Ethiopian Sacred Forest (…)

ABSTRACT

The study investigated the vegetation diversity as a driver of avian richness and seasonality in Ethiopia's sacred forest habitats in the southern Lake Tana watershed during the wintering and breeding periods. The study was conducted in three historically significant sacred forests of the Ethiopian Orthodox churches. Data collection took place from November to December and from March to April 2022, utilising systematic random sampling to establish point-count plots for assessing bird diversity and abundance. A total of 163 avian species were recorded. Two of them were endemic, 11 near-endemic, and 24 highland biome species. The richness of birds and abundance were notably higher in the post-rainy time (H = 4.51); the interior and edge habitat diversity were H = 4.39 and H = 4.33, respectively. Diversity indices indicated a more even distribution of bird species in the post-rainy time, while dominance enlarged at the edge forest in the dry periods, relatively. The study further uncovered significant correlations between bird richness and tree richness and abundance, highlighting the essential impact of vegetation diversity in supporting avian populations. The multiple regression analysis considering the factor scores in the Principal Component Analysis reveals that the linear combination of tree richness or tree abundance has a significant effect in determining bird richness (R ² = 0.796, p < 0.001) than DBH (diameter of tree at breast height), tree basal area, and tree height, which were not significant predictors. Overall, conservation efforts should prioritise enhancing vegetation diversity in less disturbed areas of church forests to sustain avian populations. We recommend that continued research is crucial to explore the multifaceted relationships between other vegetation variables such as canopy cover, tree age and anthropogenic factors with avian dynamics.