1991 by the Tenyu Maru threatened approximately 10% of the Harlequins wintering in 

 Washington (G. Schirato pers. comm. in Clarkson 1994). Even in the remote western Aleutian 

 Islands where most Harlequin winter, sparse but wide-spread oil pollution is a potential threat 

 {Byxdetal. 1992). 



Wintering Harlequins concentrate in several areas along the Pacific coast for feeding and 

 molting. Among these concentration areas is the east shore of Vancouver Island where toxic 

 pollutants are abundant (Waldichuk 1983 in Clarkson 1994). Additionally, commercial, 

 industrial, and recreational development are growing rapidly in this area. 

 Degradation of habitat: breeding and wintering. 



Breeding. In 1 992, a gas pipeline project was started which crosses the Moyie River in 

 Idaho 8 times (Cassirer 1995). Because Harlequins were known to use this stream, a study was 

 begun when siltation was noted from construction. The study showed that he siltation caused a 

 decline in the Harlequins' macroinvertebrate food source; no young were successfully raised that 

 year (Cassirer 1995). Recovery of macroinvertebrates was expected to occur within a year; 

 indeed. Harlequins successfully bred the following year. The effects of the construction could 

 have been minimized if the work had been done in late summer (after 1 September) or fall. The 

 long term effect of the loss of one year's production on this already small population is yet not 

 known (Cassirer 1995). However, Harlequins did attempt to breed (unsuccessftilly) despite the 

 disturbance and did not move to nearby streams. 



MANAGEMENT 



Federal 



Fish and Wildlife Service. Neither the Atlantic nor Pacific populations are listed as 

 Threatened or Endangered in the United States. The Harlequin Duck was listed as a Category 2 

 Candidate Species prior to 1996 at which time that Category was administratively eliminated. It 

 is legally hunted in the Pacific states and provinces under the Migratory Bird Treaty Act and 

 under state, provincial and federal regulations. Hunting is closed on the Atlantic flyway. 



National Park Service. A seasonal boating closure was instituted on McDonald Creek 

 above Lake McDonald in Glacier National Park in 1995 to protect Harlequin Ducks; the stream 

 is closed to boating from 1 April though 30 September (J. Ashley pers. comm.). To protect 

 wildlife, no boating on rivers is allowed in Yellowstone National Park. No U.S. National Park 

 Service management plan exists for the Harlequin Duck. 



Forest Service. The Harlequin Duck is a Sensitive Species in the Northern, Rocky 

 Mountain, and Pacific Northwest Regions. Forest Service policy states that Sensitive Species 

 should be managed to ensure that populations do not become Threatened or Endangered. 



States/Heritage Programs. The Harlequin Duck is classified as a state sensitive species 

 in Oregon, a priority habitat species in Washington, and a species of special concern in Idaho and 

 Montana. 



Other legal status. The Atlantic population of the Harlequin Duck is listed as Endangered 

 by the Canadian Wildlife Service. 



Mitigation procedures. None found. 



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