Conserving large mammals on small islands: a case study on one of the world’s most understudied pigs, the Togean Islands babirusa

Abstract

Abstract Conserving large mammals on small islands poses a great challenge, given their high resource demand within the limited space available. The endangered Togean Islands babirusa (Babyrousa togeanensis) is one of these species, with a distribution range limited to four small islands in the Togean Archipelago, Indonesia. Despite being listed as endangered, very little information is available on the distribution and ecology of this species. To address this critical knowledge gap, we here report the first field-based ecological study of the Togean Islands babirusa across its entire distribution range. Following a stratified random sampling procedure, we distributed camera traps at 103 stations across four islands to collect data on the species distribution from July-October 2022. We performed an occupancy modeling analysis to assess the species' habitat use, with various habitat features estimated through remote sensing and field measurements as covariates. We found that forest and mangrove availability over a large area positively influenced babirusa habitat selection. Babirusas only made use of agricultural areas when large forest areas were available nearby. Our results highlight the benefits of redesigning the national park area to accommodate babirusa habitat requirements, specifically by reassigning the non-forested park areas (about 30% of the park area) to non-protected forests currently outside the park boundary (about 50% of total forested area). Our case study exemplifies key challenges associated with conserving large mammals on small islands and highlights the importance of following an adaptive management approach, which in this case implies shifting 30% of the current protected area.