Samenvatting

The Bawean warty pig (Sus blouchi) is an endemic confined to the 192 km2 Bawean island in the Javasea. Due to a lack of quantitative ecological research, population assessments have so far been based solely on interviews with local inhabitants. Hunting and habitat degradation in Bawean’s protected areas might have caused the species to have become very rare. From 3 November 2014 until 10 January 2015, a camera trap study was conducted on Bawean to provide the first quantitative population assessment of Sus blouchi and to provide sufficient data for a Red List Assessment. In total, camera traps were placed at 100 locations. These reached 669.6 camera days and captured 92 independent Sus blouchi videos. Camera trapping reached satisfactory precision after 500 camera days. Based on these results an estimated 233-466 individuals are expected to be present on the island. Activity patterns and habitat data indicate that Sus blouchi is mainly nocturnal and prefers semi-open cultivated areas for foraging. Based on the lower population estimate Sus blouchi would qualify for categorization as Endangered on the IUCN Red List, but multi-annual data on habitat degradation on Bawean is still needed to see if the species should not be listed as Critically Endangered instead.