The global distribution of the Narcondam Hornbill is restricted to the small Narcondam Island spread over an area of 6.8 sq. km in the Andaman Sea. In this study, we describe the nest site characteristics, and abundance of the Narcondam Hornbill nest tree species based on 33 nests (active and potential) that we observed during our study period. We describe nests that we found in 13 tree species including some species which have not been reported in the past literature. The nest trees varied in girth from 103 – 380 cm, and the nest height varied from 4 – 31 m. Abundance of most of the nest tree species was highest in the low (0 – 200 m above mean sea level (ASL)) and mid (200 – 400 m ASL) elevations. The overall density of large trees decreased from lower to higher elevations pointing towards potential reduced nesting opportunities in higher elevations. While more than 57% of cavities were between north-west and north-east facing, 21% of the cavities were south-west and west facing. We have also compiled the list of known Narcondam Hornbill nest tree species based on this and previous studies. 

This data was collected as part of a larger project on the Narcondam Hornbill ecology. We conducted field work on Narcondam Island between December 2019 and February 2020. During the field work, we found nests of Narcondam Hornbill which were confirmed by revisits at most nests and by determining their status prior to our end of field work in February. Many nests were active by the time we left the island. For active and potential nests, we measured girth at breast height (1.4 m) using a measuring tape for non-buttressed trees. For trees with buttress, girth was visually estimated at a point of the trunk from where the buttresses emerge. Nest height and tree height were measured using a rangefinder. Nest orientation was determined using a Garmin eTrex 30 GPS.

Readme file has been provided that gives additional details of the study.