42 USGS/BRD/ITR-2000-0012 



Carter et al. 1992, 1996; Appendixes C and D). Near 

 colonies in northern and central California, such 

 attendance has been noted at Rock R, Sugarloaf Island, 

 and Martin's Beach (Figures 2. 1 and 2.2; Appendixes C 

 and D). In addition, such attendance was recorded south 

 of known breeding areas in Mendocino and Sonoma 

 Counties at Newport Rocks, Kibesillah Rock, Goat 

 Island Area, White Rock, and Gualala Point Island 

 (Figure 2.1; Appendixes C and D). Briggs et al. (1983) 

 also noted murres on Bruhel Point Rocks (herein referred 

 to as Newport Rocks). H. L. Cogswell (unpublished field 

 notes) also noted at least 30 murres "resting on coastside 

 rock in ocean below sea cliff at Pillar Point or Moss 

 Beach on 27 November 1 952 and at least 6 murres on "a 

 small rocky islet offshore" of West Cliff Drive at Santa 

 Cruz on 23 July 1967 (Figure 2.2). 



Carter et al. ( 1 992) classified attendance at Rock R 

 and Goat Island Area in 1 989 as newly-formed colonies 

 without determining whether eggs were laid. Here, we 

 reclassified these observations as "attendance without 

 confirmed breeding." Breeding was ultimately verified 

 at Kibesillah Rock, Newport Rocks, and Goat Island 

 Area on 12-13 July 1997, when about 5-10 chicks and 

 clumps of other birds in incubation or brooding postures 

 were observed by telescope from the mainland (G. J. 

 McChesney, personal observation). In retrospect, these 

 colonies appearred to be forming during the 1989-95 

 period. Numbers of murres at Newport Rocks and 

 adjacent Kibesillah Rock increased from 7 birds in 1993 

 to 542 birds in 1995 (Carter et al. 1996). Similarly, small 

 numbers of birds were noted at Goat Island Area in 1989, 

 1994, and 1995 and at Rock R in 1980, 1989, and 1994 

 (Sowlsetal. 1980; Carter etal. 1992, 1996). From 1989 

 to 1995, birds were present in clumps or rows, with some 

 individuals in incubation postures (as seen in aerial 

 photographs), which suggests possible breeding. In 

 addition, one murre was observed carrying a fish 

 (possibly to feed a chick or for courtship) in flight to the 

 Goat Island Area in June 1989 (Carter et al. 1992; 

 unpublished survey data). However, breeding probably 

 was not occurring at Newport Rocks (1993-95) and 

 Sister Rocks (1989-95), where all birds were standing 

 and scattered during aerial photographic surveys. 



Population Trends in Central California, 

 1979-1995 



From 1979 to 1982, overall numbers of murres 

 attending colonies in central California increased 

 (Figures 2.3 and 2.4; Appendix C; Sowls et al. 1980; 

 Briggs et al. 1983). This increase was well documented, 

 mainly at the largest colony at the South Farallon Islands 

 where boat and ground surveys also documented the 

 increase (Boekelheide etal. 1 990; Takekawa et al. 1990; 



Sydeman et al. 1997). At the South Farallon Islands, the 

 increase reflected part of a long-term increase that began 

 in the 1950s (Appendix B; Carter 1986; Boekelheide et 

 al. 1990; Sydeman et al. 1997). No increase occurred at 

 the nearby North Farallon Islands during that time, 

 possibly because of total occupation of more limited 

 available breeding habitat (see Appendix I: Figure 1-9) 

 and lower levels of past human disturbance compared 

 to the South Farallon Islands. Counts at Point Reyes 

 and the Points Resistance-Double complex varied, but 

 also seemed to increase from 1979 to 1 982. The effects 

 of low overflights by aircraft (and possibly close 

 approach by boats) may have contributed to this 

 variation in numbers. However, the Gulf of the Farallones 

 National Marine Sanctuary was created in 1981, which 

 prohibited low overflights (below 1 ,000 feet or 305 m) 

 over the colonies. McChesney et al. (1998) also clarified 

 that counts in 1979-81 at Point Reyes underestimated 

 numbers of murres present because of incomplete and 

 low-quality photographs. Taking this into account, little 

 change was evident at Point Reyes between 1979 and 

 1982. Between 1980 and 1982, murre numbers were 

 reduced at the Devil's Slide complex and decline was 

 evident at the Castle-Hurricane complex. 



Between 1979 and 1989, all colony complexes in 

 central California underwent large declines of 8.7 to 

 28.5% per annum, (0.001 < P < 0.020; Figure 2.3; 

 Appendix H). The overall population declined 9.9% 

 per annum (P = 0.002; Figure 2.4; Appendix H). Most 

 decline occurred between 1982 and 1985, as further 

 verified with ground-based observations at the South 

 Farallon Islands (Boekelheide et al. 1990; Takekawa et 

 al. 1990). Plot observations and ground and boat surveys 

 at the South Farallon Islands showed low attendance 

 and low breeding success during the severe 

 El Nino-related breeding conditions in 1983-84 

 (Boekelheide et al. 1990; Takekawa et al. 1990; 

 Sydeman et al. 1997). Although no aerial photographs 

 were taken in 1983-84, numbers at colonies in 1985 

 and 1986 after breeding conditions had returned to 

 normal were still much lower than in 1981 and 1982 

 (Appendix C). By 1986, the Devil's Slide Rock and 

 Mainland colony had essentially disappeared with 

 between and 1 28 murres in 1 986-87 and 0-5 murres 

 in 1988-95. 



Between 1987 and 1990, counts at most colonies 

 reached their lowest levels compared to 1981-82 

 (Figure 2.3; Appendix D). The Castle-Hurricane 

 complex reached the lowest level of all extant colony 

 complexes (1,047 and 1,093 birds counted in 1988 and 

 1989, respectively) with loss of subcolonies and only 

 small groups of birds on several remaining subcolonies. 

 The small Millers Point Rocks colony (within the Points 



