The Disappearance of Hornbills in Sabang Island: A Seven-Day Expedition

*Heri Tarmizi

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Despite our efforts, no native or introduced hornbill species were observed in any of the surveyed areas.

Introduction

Sabang Island, located at the northern tip of Sumatra, Indonesia, is a small but ecologically significant area separated from the mainland by the Malacca Strait, approximately 35 kilometers away. Despite its size, the island boasts a variety of habitats, from lowland to highland forests, making it a potentially ideal environment for diverse wildlife, including hornbills. This report details the findings of a seven-day expedition aimed at mapping the spring migratory behavior of raptors using the Thailand and Andaman flyways, while simultaneously investigating the presence of hornbills on the island.

Methodology

The expedition team comprised four dedicated members: Dhea Ramadhani, Nisa Khairunnisa, Rilla, and myself. Our methodology combined direct observation with community interviews. We surveyed various strategic locations known for their rich biodiversity, including Balohan, Danau Anak Laut, 0 KM Forest, Pria Laot, Goa Sarang, and Balik Gunung. These sites were selected for their varying altitudes and forest types, which are conducive to hornbill habitation. 

In addition to field observations, we conducted interviews with local residents to gather historical and present-day accounts of hornbill sightings. This mixed-method approach aimed to provide a comprehensive understanding of the hornbill population status and the ecological potential of Sabang Island.

Findings

Our intensive field observations over the seven-day period yielded no sightings of hornbills. This absence was surprising given the island's rich floral diversity, which includes numerous tree species suitable for hornbill nesting and feeding. Despite our efforts, no native or introduced hornbill species were observed in any of the surveyed areas.

The community interviews corroborated our field observations. None of the local residents reported recent or historical sightings of hornbills. This lack of anecdotal evidence suggests that hornbills have either never inhabited Sabang Island or have been extirpated from the region over time.

Ecological Potential of Sabang Island

Despite the absence of hornbills, Sabang Island possesses significant ecological potential. The island's forests are home to a diverse range of tree species that provide ideal nesting and feeding habitats for hornbills. These trees produce fruits and have cavities suitable for nesting, which are critical for hornbill survival and reproduction.

The presence of such ecological resources indicates that the habitat quality on Sabang Island is not a limiting factor for hornbill habitation. The forests' structural complexity and floristic composition are conducive to supporting hornbill populations, should they be reintroduced or naturally colonize the island.

Discussion

The absence of hornbills on Sabang Island raises several questions regarding the factors influencing their distribution and population dynamics. One possibility is that hornbills have never established populations on the island due to geographical isolation and the challenges of dispersal across the Malacca Strait. Alternatively, historical factors such as habitat destruction, hunting, or other anthropogenic pressures may have led to their local extinction.

The results of our expedition suggest that while the ecological conditions on Sabang Island are suitable for hornbills, other factors have prevented their presence. Further research is needed to understand the historical biogeography of hornbills in the region and to assess the feasibility of conservation initiatives such as habitat restoration and species reintroduction.

Conclusion

Our seven-day expedition to Sabang Island, while primarily focused on mapping raptor migratory patterns, provided valuable insights into the status of hornbills in the area. The complete absence of hornbill sightings, despite extensive surveys and community interviews, highlights a significant gap in the island's avian biodiversity. However, the ecological potential of the island's forests suggests that habitat suitability is not a limiting factor.

Future conservation efforts should consider the potential for reintroducing hornbills to Sabang Island, leveraging the existing ecological resources. Such initiatives could enhance the island's biodiversity and contribute to the conservation of hornbill species in Indonesia. Collaborative efforts involving local communities, conservation organizations, and government agencies will be crucial to the success of such endeavors.

Bibliography

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- Kinnaird, M. F., & O’Brien, T. G. (2007). The Ecology and Conservation of Asian Hornbills: Farmers of the Forest. University of Chicago Press.

- BirdLife International. (2020). Buceros bicornis. The IUCN Red List of Threatened Species 2020.

- Indonesian Ministry of Environment and Forestry. (2021). Indonesian Biodiversity Strategy and Action Plan 2015-2020. Ministry of Environment and Forestry.