Impact of Habitat Pressure Variables on Forest Interior Bird Species in the Seshachalam Hills, Eastern Ghats, India

Abstract

This study in the Seshachalam hills of the Eastern Ghats in Andhra Pradesh, India assesses the impact of habitat pressure variables on the population of forest-interior bird species. Field investigations from January to December 2025 in eight ecologically sensitive forest areas documented thirty three forest-interior bird species. Fifty geo-referenced sampling points and twelve transects were surveyed using a mixed-method ecological design. Fixed-radius point counts, line transects and opportunistic observations including GPS-enabled mapping was used to study avian diversity. Habitat pressure variables such as deforestation, fragmentation, presence of invasive plants, and human activity were quantified using GIS-based landscape metrics, and field indicators. Pearson’s correlation coefficient (r) was used to examine relationships between habitat pressures and species abundance. Abundance of forest-interior bird species indicated presence of a good canopy cover and presence of a rich undergrowth in the region. Insectivorous species were abundant reflecting healthy availability of insect species. Forest-interior birds were abundant in mature forest habitats, especially in areas with dense undergrowth. Statistical analysis revealed strong negative correlations between bird abundance and habitat pressure variables such as deforestation (r = −0.70 to −0.85), fragmentation (r= −0.69 to −0.84), and human disturbance (r = −0.68 to −0.79). Species like the Indian Pitta and Heart-spotted Woodpecker showed the highest sensitivity to habitat degradation. Presence of Invasive plants showed moderate positive correlations (r = 0.35–0.44) with some insectivorous species. The findings reveal the importance of conservation of mature forests which is essential for sustaining forest-interior birds in the Seshachalam Biosphere Reserve.