June 2017
This is the final report for objective 6 of the Chatham Island Seabird Population Research 2016/17.


Annual aerial surveys to count the breeding population of Chatham Island shags were carried out during the 2014, 2015 and 2016 breeding seasons. Each season two aerial surveys of all colonies were undertaken, with an additional early flight in 2016 to count the colonies in Te Whanga Lagoon.

The number of Chatham Island shags was estimated at 856 breeding pairs, found in 13 breeding colonies.

This result is very similar to that recorded in 1997 (842 pairs) but significantly higher than counts from 2003 and 2011. Methodology was the same in the 1997 and 2014-2016 counts and suggest the Chatham Island shag population has been stable for the last 20 years.

Aerial surveys are an effective method at counting Chatham Island shags, and this method is recommended for ongoing monitoring of this species. The use of multiple flights is highly recommended to get accurate results.

Publication information

Bell, M.D., Bell, D.J., Boyle, D.P. & Tuanui-Chisholm, H. 2017. Chatham Island Shag census 2014-2016. POP2016-01 Chatham Islands seabird population research 2016/17. Technical report prepared by Wildlife Managment Ltd for the Conservation Services Programme, Department of Conservation, Wellington. 11 p.


Conservation Services Programme
Department of Conservation
PO Box 10-420
Wellington 6143


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