Population densities of understorey birds across a habitat gradient in Palawan, Philippines: implications for conservation

A study of understorey bird populations in Puerto Princesa Subterranean River National Park, Philippines, reveals that old-growth forests are critical for conserving Palawan's endemic and threatened birds. While some species thrive in disturbed habitats like cultivation, the highest densities of 11 species—including five endemics and three threatened ones—were found in undisturbed forests. The research highlights the importance of retaining large trees to sustain suitable microhabitats, cautioning against expanding cultivated areas within protected zones. Though population estimates for threatened species may be higher than previously thought, the study underscores the need for stronger conservation management across Palawan's protected areas.

Mallari, N. A. D., Collar, N. J., Lee, D. C., McGowan, P. J. K., Wilkinson, R., & Marsden, S. J. (2011). Population densities of understorey birds across a habitat gradient in Palawan, Philippines: implications for conservation. Oryx, 45(2), 234–242. https://doi.org/10.1017/s0030605310001031