Diversity and Feeding Guild of Birds Along Gradient of Revegetated Area in Karst Ecosystem: a Case Study from Rembang, Central Java

Abstract

In the mining industry, the provision of new habitats through land rehabilitation and afforestation is an important step to anticipate the loss of bird biodiversity. Positive impacts of rehabilitation and afforestation thus can be identified from the results of periodic monitoring. The turnover of bird communities associated with afforestation is related to changes in structural habitat features that provide food and shelter. The study aimed to understand the community assemblages and feeding guild structure in a revegetated area of karst in Rembang, Central Java. Three locations (EDP, GBC, and GBL) were selected as observation sites and characterized by different land use, vegetational age, and floral composition. Surveys were conducted using the point count method in early April for three consecutive years (2020-2022). We have identified 32 bird species from 29 genera and 22 families. Most birds are considered generalist, cosmopolitan, and well-adapted to various habitats. Total species richness (19.33±3.22 to 20.67±4.12) and value of diversity index (H’ = 2.41±0.14 to 2.56±0.29) have only slightly differed among locations. Species richness and total abundance in each site tend to increase along periods of observation, suggesting that bird community changes in response to further structural habitat changes that occur as vegetations age. Furthermore, higher abundance occurred in larger areas or sites with more native plant species. The feeding guild consists of 7 groups and is dominated by insectivores, both based on the number of species (46.88%) and individuals (49.07%). The results of the study are expected to help identify more appropriate management of conservation and habitat restoration in the area.