BIOLOGY AND CONSERVATION OF THE COMMON MURRE 91 

 Table A-3. Summary of aerial photographic surveys of common murre colonies in Oregon and Washington. 1979-1 995.* 



"See Appendixes E, F, and G 

 "Unpublished data 



late July. The time of day and time of the breeding season 

 when surveys were conducted roughly matched 

 methodology in California, but survey dates were later 

 due to the later breeding phenology in this area. During 

 1 979-94. photographs were taken with a 35-mm camera 

 and a 1 35-mm lens. In 1995, the colonies were 

 photographed with a 70-200-mm lens. Only Kodak 

 Ektachrome 400 ASA film was used. Counting murres 

 from slides involved projecting the transparencies onto 

 a paper flip chart. Small groups of murres (less than 30) 

 were circled and then counted with a tally counter. This 

 process w as repeated until the entire colony was counted. 

 When murres were densely packed, or with poor slide 

 resolution, the number of birds within small groups was 

 estimated. A general k correction factor of 1 .67 (based 

 on California data) was applied to all count data to 

 estimate the number of breeding adults at colonies. No 

 study has calculated a k specific to Washington 

 colonies. 



As in Oregon (see above). Ecological Consulting 

 Incorporated conducted murre colony counts in 

 Washington in late June 1989 (Briggs et al. 1992). On 

 June 27 and 28. they made a nonstandardized aerial 

 survey of murre colonies using visual estimation and 

 aerial photography. The uncorrected total was 12,810 

 birds, with 830 at Tatoosh Island (Briggs et al. 1992). 

 On 22 June, USFWS personnel counted 3.925 birds 

 (excluding Tatoosh Island; see Appendix F). Data 

 obtained by Ecological Consulting Incorporated were 

 considered inaccurate and were not used for trend 

 analyses in Chapter 2 because (1) nonstandardized 

 survey techniques were used, (2) the survey did not 

 include some active murre colonies in Washington in 

 1989, (3) some counts were reported for rocks where 

 murre colonies were not present, and (4) counts for many 

 colonies were lumped together as a single count. Where 

 1989 standardized counts by the USFWS can be 

 compared with those of Briggs et al. (1992), there are 



