Bas (Sebastianus) van Balen
Ornithological Identification Specialist
PhD
📍 Netherland
Provides expert identification and verification of difficult or ambiguous bird observations, based on photographic and audio evidence, where species identity cannot be confidently determined by the verification team.
Countries I work in
Indonesia
Expertise
Bas is a Dutch freelance ornithologist and biodiversity consultant who has worked extensively in Indonesia for more than four decades, beginning with two years of student fieldwork in West Java in 1979–81. He has since worked throughout the Indonesian archipelago, including Java, Sumatra, Kalimantan, Sulawesi, the Lesser Sundas, the Moluccas and Papua. He holds a PhD from Wageningen University, with a dissertation on the persistence of birds in fragmented forests of Java and Bali.
His work has included bird surveys, biodiversity assessments, environmental impact assessments, conservation planning, training and capacity building, and biodiversity monitoring. In recent decades, much of his fieldwork has focused on Sumatra and Kalimantan, particularly bird surveys supporting High Conservation Value (HCV) assessments and monitoring in forests, plantations and other landscapes.
Bas has made a longstanding contribution to Indonesian ornithology through scientific documentation and editorial work. His extensive collection of recordings made during his fieldwork is largely deposited with the British Library of Wildlife Sounds and available through xeno-canto, while others have been published in books, CDs, DVDs, apps and scientific publications.
He has been a member of the Indonesian Ornithological Society since 1985 and has served as co-editor of Kukila, the Journal of Indonesian Ornithology, since 1992. He has contributed to bird field guides, species distribution databases and international bird checklist projects, and has worked with organisations including BirdLife International, Wildlife Conservation Society, Conservation International, WWF-Indonesia, Fauna & Flora International and Burung Indonesia.