Wetlands provide habitat for some of New Zealand’s most secretive and difficult to detect threatened bird species, including crakes and rails. However, it is currently difficult to measure population trends for these birds in relation to conservation management activities due to a lack of standard monitoring methods.

This report reviews the use of call-count methods for surveying and monitoring members of the family 'Rallidae' worldwide to determine whether they could form the basis for developing monitoring techniques in New Zealand.