100 USGS/BRD/ITR-2000-0012 



Devil's Slide Complex (San Pedro Hock and 

 Devil's Slide Rock and Mainland) 



Bryant ( 1 872) displayed an engraving of San Pedro 

 Rock with birds (probably murres but not identifiable 

 to species) on this rock. He further remarked (p. 567) 

 that "The old promontory, now become an isolated crag, 

 is covered with sea-birds, and its top is already white 

 with their guano, ..." 



The murre colony at San Pedro Rock was first 

 mentioned by Ray (1904). In 1908, the colony was best 

 documented when it was being extirpated by eggers 

 who still sold murre eggs in the San Francisco market 

 (Ray 1909). On 12 July, about 20 birds and eggshell 

 fragments were left on the rock. However, a fisherman 

 reported collecting "as many as thirty dozen [or 360 

 single] murre eggs on a trip" in previous years (Ray 

 1 909). The colony has not been reported as active since, 

 though H. Cogswell (unpublished field notes) noted 40 

 or more murres on 29 April 1972 as he passed by in a 

 small plane. 



The Devil's Slide Rock and Mainland colony is 

 located about 1 .6 km ( 1 mile) south of San Pedro Rock, 

 along an inaccessible part of the coast. This colony was 

 not discovered until after Highway 1 was built across 

 Devil's Slide in 1937. Totals of 150-200, 75, and about 

 100 murres were reported breeding on 5, 8, and 1 1 June 

 1938, respectively, by Stephens and the Parmenters 

 (Anonymous 1938; Linsdale 1938). On 27 July 1939, 

 Parmenter reported murres "still nesting" at Devil's Slide 

 Rock (Anonymous 1939; Sibley 1952). Similarly, 

 Parmenter noted 100 murres on Devil's Slide Rock on 

 9, 24 and 28 July 1941 (L. O. Williams, unpublished 

 field notes). On 11 April 1954, 13 July 1954, and 12 

 July 1959, H. Cogswell (unpublished field notes) noted 

 200, 180, and 200 murres on Devil's Slide Rock, 

 respectively. In 1970, Osborne and Reynolds (1971) 

 and Osborne ( 1 972) reported 350 breeding pairs from a 

 mainland count. Hundreds to thousands of murres are 

 evident in a photograph (without additional 

 information) that was probably taken in 1970-72, 

 possibly by R. Jurek or J. G. Reynolds (Sowls et al. 

 1980; unpublished data). 



These colonies are located close to the Golden Gate, 

 so murres there probably were affected heavily by oil 

 pollution in the early twentieth century (Ainley and 

 Lewis 1974; Chapter 3), which may have contributed, 

 with egging, to the loss of the San Pedro Rock colony at 

 this time. Both colonies also probably were affected by 

 the construction (1905-08) and operation (1908-20) 

 of the Ocean Shore Railroad that ran from San Francisco 

 to Santa Cruz. In 1906, a tunnel was blasted through 



San Pedro Point, a railroad bed was blasted along 

 Devil's Slide, and a large "saddle cut" was blasted south 

 of Devil's Slide (Stanger 1963; VanderWerf 1992). 

 Railroad construction between San Francisco and 

 Granada was completed in 1908. In 1908, a fisherman 

 reported that "the birds had become scarce [at San Pedro 

 Rock] owing to the continued blasting" during railroad 

 construction (Ray 1909). The railroad was plagued by 

 landslides and was often rebuilt along Devil's Slide until 

 its demise in 1920. The railroad was built by Greek, 

 Sikh, and Japanese immigrant workers who lived in the 

 general area. Greek immigrants were well known for 

 egging activities at the South Farallon Islands between 

 1880 and 1900 (see above). The railroad also brought 

 many people to the San Pedro Point area. In the spring 

 of 1908, 3,000 excursionists traveled from San Francisco 

 to Tobin Station near San Pedro Point, prior to the 

 opening of the railroad to Half Moon Bay (VanderWerf 

 1992). Thus, the railroad may have provided many 

 opportunities for people to discover breeding murres 

 and conduct egging at San Pedro Rock. 



Castle-Hurricane Complex (Hurricane Point Rocks 

 and Castle Rocks and Mainland) 



Murres were first noted breeding at Hurricane Point 

 Rocks in 1940, after Highway 1 was opened through 

 this previously inaccessible (except by boat) area in 

 1938. Murres apparently bred only at Hurricane Point 

 Rocks, especially the larger rock, between 1940 and 

 1950. On 23 May, about 200 murres were noted on 

 Hurricane Point Rocks and they were present on 25 

 May 1940. Williams remarked that "Guy Emerson 

 discovered colony on May 21 or 22 1940" (L. O. 

 Williams, unpublished field notes). From 1940 to 1945, 

 L. O. Williams (unpublished field notes) recorded murres 

 several times at Hurricane Point Rocks but not at the 

 nearby Castle Rocks and Mainland colony, where he 

 did record other bird species. Murre observations were 

 reported as follows: between 270 and 300 on 19 June 

 1940, 200 on 15 July 1940, 300 on 1 1 July 1941, 280 

 on 25 April 1942, 500 on 29 June 1943, 500 on 29 June 

 1943, with the remark that the colony had "seemed to 

 show a slight increase over 1940", and 600 on 20 May 

 1945. Several hundreds also were reported by the 

 Andersons at Hurricane Point Rocks on 23 June 1950 

 (L. O. Williams, unpublished field notes). On 12 June 

 1955, Williams reported 530 birds "present in colony" 

 at Hurricane Point Rocks (American Birds Files; 

 Cogswell and Pray 1955b). Storer (1952) reported 

 Hurricane Point as a colony, but without details. 



Osborne and Reynolds (1971) and Osborne (1972) 

 reported 200 and 1 00 breeding pairs at Hurricane Point 

 Rocks and Castle Rocks and Mainland, respectively, 



