BIOLOGY AND CONSERVATION OF THE COMMON MURRE 57 



To examine population trends, we divided 

 locations attended by murres into two geographic 

 sections, southern Washington with 6 known colonies 

 in Grays Harbor County and northern Washington 

 with 12 known colonies in Clallam and Jefferson 

 Counties (Figure 2.9). These areas had been identified 

 in previous studies as having different murre population 

 trends (Wilson 1991; Rarrish 1995). No murre colonies 

 have ever been reported in the inland marine waters of 

 Washington's Juan de Fuca Strait, San Juan Islands and 

 Puget Sound (Speich and Wahl 1989). 



Murres were counted annually by the USFWS along 

 the outer coast of Washington from 1979 to 1995, 

 except Tatoosh Island which was surveyed aerially only 

 in 1994-95 (Appendixes F and G). Routine aerial 

 surveys were not conducted at the Tatoosh Island 

 complex from 1979 to 1993 because this colony was 

 not part of the Washington Islands National Wildlife 

 Refuge (consisting of Flattery Rocks, Quillayute 

 Needles, and Copalis National Wildlife Refuges). Few 

 birds (e.g., 200 birds in 1978; Speich and Wahl 1989) 

 attended Tatoosh colonies (Appendixes F and G) in the 

 late 1970s. By adding 200 birds to the USFWS 1979 

 aerial survey total of 3 1 ,520 birds for all other locations, 

 a total count of 31,720 birds for 1979 was derived. 

 Speich and Wahl (1989) derived a similar total (30,780 

 birds) by combining raw counts from the late 1 970s and 

 early 1980s. By applying a k correction factor to the 

 1979 total, we estimated the breeding population for 

 Washington at about 53.000 breeding birds. Southern 

 and northern Washington accounted for 86% and 14%, 

 respectively. 



In late June 1989, murre colony counts in 

 Washington were conducted by a private consulting 

 firm (Briggs et al. 1992) but, because of numerous 

 problems (i.e., different survey techniques and 

 incomplete surveys), we relied only on data from 

 standardized USFWS surveys for trend assessments (see 

 Appendix A). However, if we add 830 birds for Tatoosh 

 Island (Briggs et al. 1992) to the USFWS total of 3,925 

 birds (which excluded the Tatoosh Island complex), a 

 total count of 4,755 murres was derived for 1989, which 

 corresponded to about 7,900 breeding birds. Certainly, 

 numbers of murres in Washington were much lower in 

 1 989 than in 1 979 (Figure 2.10), and only 28% occurred 

 in southern Washington. 



In 1994 and 1995, breeding population estimates 

 for murres in Washington were 5.900 and 9,600 breeding 

 birds, respectively, based on the results of the 5 July 

 1994 and 25 June 1995 USFWS aerial photographic 

 surveys (Appendix G), which included the Tatoosh 

 Island complex. The Tenyo Maru Oil Spill National 

 Resource Trustees (2000) estimated the 1995 murre 

 population in Washington at 13,600 birds by adding a 

 median count of 5,230 birds from USFWS 1995 refuge 

 surveys (excluding Tatoosh Island) to a 1995 ground 

 count of 3,720 murres on Tatoosh Island (Parrish 1996) 

 and applying a k correction factor of 1 .6. The proportion 

 of Washington murres attending southern Washington 

 locations was between 1 and 14% in 199495. 



In southern Washington, colonies occur in 

 complexes at Point Grenville and Split-Willoughby. 

 Peak numbers were estimated in 1979 at Point Grenville 

 (21,400 breeding birds) and in 1982 at Split- 



40 



Washington 



Figure 2.10. Trends in whole-colony counts g 



for common murres in Washington, 1 979- | 



1995. excluding Tatoosh colonies (see - 

 Appendix H). 



E 



s 



I 



= 



1978 1980 1982 



1984 1986 1988 1990 

 Year 



1992 1994 19% 



