PRTORTTIES FOR FUTURE RESEARCH 



The following are among the top future research priorities and are primarily a subset of those 

 listed by the Harlequin Duck Working Group (1993) and by Cassirer et al (1996). The Montana 

 Natural Heritage Program has developed research proposals to address the priorities for those 

 questions associated with the breeding grounds and migration and is pursuing funding for them; 

 these are available from the Natural Heritage Program. 



1) What are the impacts of human disturbance on breeding and wintering Harlequin Ducks? 



Several independent studies have documented the sensitivity of Harlequin Ducks to 

 human disturbance, primarily through the relationship of sighting locations to the accessibility of 

 those locations (Kuchel 1977, Wallen 1987, Diamond and Finnegan 1993, Cassirer and Groves 

 1991, 1994, Clarkson 1992, Ashley 1994). Specifically, boating has been shown to have a 

 significant negative correlation with numbers of ducks present in one area on a medium-sized 

 stream (Clarkson 1992, Hunt 1993). Observ'ations in other areas tend to support this conclusion 

 (Cassirer and Groves 1991, Brady pers. comm. in Clarkson 1992) though it may not be the case 

 in very large streams (Smith 1996). Fishing and human presence have also been suggested as 

 causes of disturbance; however, though specific examples exist for both disturbances, statistical 

 data analyses are lacking (Wallen 1987, McEneaney 1994, Cassirer and Groves 1991). 



Other than for boating (Clarkson 1992, Hunt 1993), wide-scale analyses have not yet 

 been attempted nor have analyses of the effects of most specific kinds and amounts of human 

 activities. Several specific studies should be performed to address these questions. 



Initially, wide-scale data on Harlequin streams is required, including productivity; 

 population size; length of stream segments used during pair and brood seasons; categories and 

 locations of land ovwership of the streams; hydrogeological properties of the streams; habitat 

 characteristics of the streams; and current human use of the stream (by roads, trails, structures, 

 activity, etc.). A first step will be to see which of this information is already available and what 

 is lacking that needs to be gathered in the field. For example, data regarding population size and 

 length of stream segments used is already in place, while data regarding hydrogeological 

 properties, habitat of the streams, and current human use will require preliminary information 

 gathering to determine what is available. Unused and/or unknown streams that fit physical 

 parameters of used streams can then be selected and compared in respect to kind and amounts of 

 disturbance/accessibility. 



Following wide-scale analyses. Harlequin response to humans requires evaluation; initial 

 responses to surveyors could be recorded. Note that this would only provide immediate, in-sight 

 response of birds seen; presumably some birds would react prior to the surveyor seeing them and 

 thus not be observed at all. Nor would such a study reveal length of time or distance moved in 

 reaction to disturbance. A more precise but intrusive method would be to use radiotelemetry on 

 the birds. Radio-telemetry would additionally provide more accurate data on use of habitat types 

 and locations relative to human development/access points. 



Finally, when actions are taken on Harlequin streams, monitoring to determine effects of 

 those actions should be implemented, thereby providing for adaptive management and prevention 

 of futxire mistakes. Specific land management or development actions on Harlequin streams 

 should be proceeded by at least two years of baseline marking and surveying for population size 



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