LC
Little White Tern Gygis microrhyncha



Justification

Justification of Red List Category
This species has a very large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appears to be stable, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size has not been quantified, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.

Trend justification
The overall population trend is stable, although some populations have unknown trends (Wetlands International 2006).

Distribution and population

The Little White Tern can be found on the Marquesas Islands (French Polynesia), and possible the Phoenix Line Islands (Kiribati) of the Pacific Ocean (del Hoyo et al. 1996).

Threats

The Little White Tern has a stable global population. However, in parts of the range it is threatened by invasive species. House Rats Rattus rattus are thought to be the cause of an observed decline in Pohnpei in the East Caroline Islands (del Hoyo et al. 2018). The Little White Tern is known only from skeletal remains on Mangaia in the Cook Islands (Steadman and Kirch 1990) and in the Mariana Islands (Steadman 1999), with their extirpation from these areas likely due to human exploitation, habitat degradation and the introduction of invasive species (especially Rattus spp.).

Acknowledgements

Text account compilers
Martin, R., Calvert, R., Butchart, S., Stuart, A., Ekstrom, J.


Recommended citation
BirdLife International (2019) Species factsheet: Gygis microrhyncha. Downloaded from http://www.birdlife.org on 26/04/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 26/04/2019.