Should the Narcondam Hornbill be introduced on other islands in the Andaman archipelago?

Abstract

Assisted colonisation that involves the planned introduction of threatened species has generated intense debates on its merits, such as mitigating habitat loss due to climate change impacts, and challenges, such as the risk of invasion by introduced species. Here, we assess the feasibility of Assisted Colonisation of the Narcondam Hornbill, a species confined to a 6.8 km2 island in the Andaman Sea, onto other islands in the Andaman archipelago. Utilising IUCN’s framework for species introductions, we evaluate the rationale for assisted colonisation and identify potential knowledge gaps that are critical for consideration. Based on the status of the Narcondam Hornbill population and its legally protected habitat, there is limited support for the assisted colonisation of the species to other islands as per IUCN’s guidelines. However, if introduction is contemplated, we need to evaluate aspects like fruit availability on the new island, impacts of hornbill on endemic frugivores (especially those that are absent on Narcondam), influence of predators on introduced hornbill populations, low genetic diversity of Narcondam Hornbills and potential social impacts of introducing the hornbill on other islands. Given the restricted range of the species and vulnerability to stochastic events, systematic monitoring of Narcondam Hornbill populations and demography, minimising threats from avian disease and invasive rodents and potentially establishing a conservation breeding population in captivity with guidance from experts with experience in conservation breeding of hornbills is vital.

Keywords

• Conservation introduction
• Conservation breeding
• Ecological replacement
• Rhyticeros narcondami