An inventory of Harlequin Ducks was conducted between May and August of 1996 and April and May 1997 in the Nahatlatch River watershed which enters the Fraser River north of Boston Bar, British Columbia. The main objectives were to identify areas which may be used by
Harlequin Ducks, describe the habitat and to estimate the population size within the study area. Conservative
estimates of 39 (SD=8.9) and 39 (SD=14.5) ducks were generated from mark/resighting data and
observation estimates for 1996 and 1997 respectively in the upper Nahatlatch Watershed. An
estimate of 67 (SD=22.8) ducks was generated using observations from throughout the drainage in 1997. An active Harlequin Duck nest was observed in 1996 and 1997 and two broods were observed in 1996 confirming that there was successful breeding by Harlequin Ducks in the Nahatlatch River watershed during the inventory period. We were also able to positively link the Nahatlatch breeding population with the Strait of Georgia wintering population through resightings of banded ducks. Stream reaches important for pair staging as well as nesting were identified. There was an apparent association of Harlequin Ducks to areas of the watershed that
had not been disturbed by commercial harvest operations. Preservation of remaining intact riparian zones, and restoration of riparian zones elsewhere in the upper Nahatlatch River watershed are recommended.
Freeman, Shaun; Goudie, Ian R.. 1998. Abundance, Distribution, and Habitat Use of Harlequin Ducks in the Nahatlatch River. Forest Renewal British Columbia; Ministry of Environment, Lands and Parks. No. CWRP 97-79