Data from: An expedition to Narcondam: observations of marine and terrestrial fauna including the island-endemic hornbill

Oceanic islands, known for their ecologically sensitive ecosystems and endemic species, are of high conservation significance. The volcanic island of Narcondam in the Andaman and Nicobar Islands, Indian Ocean, is a prime example and the only home of the endemic and globally endangered Narcondam Hornbill. Despite its ecological and evolutionary significance, there has been limited biological exploration and research on the island over the last century. Here, we report on a 2010 expedition to Narcondam, presenting results of our rapid survey of island invertebrates, herpetofauna, mammals and birds (especially the endemic hornbill), and marine life in adjoining waters. The survey recorded dense coral growth in the surrounding waters, and identified 17 fish, 2 sea cucumber, 8 reptile, 28 bird, and 2 mammal species and 13 spider and 8 butterfly taxa. Of these, 4 spiders, 3 butterflies and 6 birds identified to species are new records for the island. The Narcondam Hornbill was frequently encountered and we report trail-based estimates of encounter rate and density, which can serve as a baseline for future monitoring. Both despite its isolation and because of it, Narcondam has faced a number of recent and serious conservation threats, including feral goats, poaching, habitat degradation around the police camp, and proposed installations. While efforts have been made by the Government authorities to stave-off various threats, we highlight the need for further scientific research and monitoring, while according primacy to strict protection and conservation.