44 



Bints — Our Livinii Rt'simncs 



Fork-tailed storm-petrel 

 (1,000's) 





12 



9 — 

 6-< 



Brown pelican 



(1,000's) 



1 -2 

 



ND 



Leach's storm-petrel 



^3 



Double-crested cormorant 



ND 



12 



9 - 

 6 — 



CM 

 CO 



3 5 

 



(1,000's) 



7 



6 



5- 

 4- 

 3- 



■^ CO 



1 - s - 

 



Ashy storm-petrel 



Brandt's cormorant 

 (10.000's) 



^H CM 



MR 



250- 

 200- 



Black storm-petrel 



Pelagic cormorant 



(1,000's) 



w 



75-80 



CA 



Year 



Fig. 1. Status and trends of breed- 

 ing populations of storm-petrels, 

 pelicans, and cormorants on the 

 west coasts of California. Oregon, 

 and Washington. Data for small 

 inland populations of while peli- 

 cans and double-crested cor- 

 morants are not included. ND — 

 no data available; — no coastal 

 nesting. Sources: CA (Hunt et al. 

 IQTg^Sowls et al. 1980. Carter et 

 al. 1992): OR (Varoujean and 

 Pitman 1979; R.W. Lowe, unpub- 

 lished data); and WA (Speich and 

 Wahl 1989; U.W. Wilson, unpub- 

 lished data). Also see Carter et al. 

 (in press) for double-crested cor- 

 morant. 



OR 

 Year 



78-82 91 

 WA 



increase probably represents greater survey 

 effort (Fig. 1). They have dechneci in northern 

 California because of the loss of burrow-nesting 

 habitats due to soil erosion and defoilation by 

 nesting cormorants (Carter et al. 1992). Ashy 

 storm-petrels (O. homochwa) have declined 

 recently at the world's largest known colony at 

 the South Farallon Islands, possibly because of 

 high gull predation (W.J. Sydeman, Point Reyes 

 Bird Observatory, unpublished data). This 

 decline is of concern because the small world 

 population of this species (fewer than 10.000 

 breeding birds) nests entirely in California. 

 Greater numbers of ashy and black storm- 

 petrels (O. iiu'lania) have been documented 

 recently in southern California, although this 

 probably reflects greater survey efforts (Carter 

 et al. 1992). In Fig. 1. similar numbers of fork- 

 tailed storm-petrels (O. fiircata) are indicated 

 over the past decade in Oregon and California 

 because survey efforts confirmed very small 

 numbers. Declines in California are suspected 

 (Carter et al. 1992), but further work is required 

 to establish trends. 



Pelicans (Pelecanidae) 



Brown pelicans have increased recently at 

 the only two remaining colonies (West Anacapa 

 and Santa Barbara islands) in the Channel 

 Islands in southern California (Fig. 1), follow- 

 ing severe pre- 1975 declines primarily due to 

 eggshell thinning from marine pollutants 

 (Anderson et al. 1975; Anderson and Gress 

 1983; Carter et al. 1992; F Gress and D.W. 

 Anderson. University of California-Davis, per- 

 sonal communication). Breeding success is still 

 low and limited recovery may involve immigra- 

 tion of birds out of Mexico. Concern exists for 

 adverse effects of continuing low levels of 

 marine pollutants, commercial fisheries, and the 

 1990 American Trader oil spill. Although the 

 brown pelican has shown recent population 

 increases, white pelicans have been extiipated 

 from parts of interior California and have 

 declined at inland colonies in northern 

 California because of low reproduction related 

 to water developments and drought (Carter et al. 

 1992; P. Moreno and D.W. Anderson. University 

 of California-Davis, personal communication). 

 Small colonies still exist at Sheepy Lake and 

 Clear Lake in the Klaniath Basin area. These con- 

 ditions also exist at other inland areas in Oregon. 

 Washington, and Nevada, but problems seem 

 fewer farther east. 



Cormorants (Phalacrocoracidae) 



Double-crested cormorants ( Plialacrocora.x 

 aiiritiis) have increased dramatically in coastal 

 regions of California and Oregon (Fig. 1) 

 because of reduced human disturbance, reduced 

 levels of marine pollutants in southern 

 California, and recent use of artificial nesting 

 areas in San Francisco Bay and Columbia River 

 estuaries (Gress et al. 1973; Carter et al. 1992). 

 They have not increased in Puget Sound 

 because of high human disturbance and preda- 

 tion by bald eagles [Haliaeetiis leucocepluilus), 

 which has caused colony abandonments (Henny 

 et al. 1989; Speich and Wahl 1989; Carter et al. 

 in press; U.W. Wilson, unpublished data). 

 Declines have been reported at interior colonies 

 in California. Oregon, and Washington due to 

 water developments, human disturbance at 

 colonies, and large-scale shooting of birds at 

 hatcheries (during smolt releases) and at aqua- 

 cultural facilities (Carter et al. in press; R.W. 

 Lowe, unpublished data; R. Bayer, personal 

 communication; P. Moreno, unpublished data). 

 Brandt's and pelagic cormorant {P. penicillatus 

 and P. pelagicus) populations have fluctuated in 

 response to El Nino conditions (Ainley and 

 Boekelheide 1990; Ainley et al. 1994). At the 

 South Farallon Islands, these cormorants appear 

 very sensitive to El Nifio conditions, which 

 result in quite poor reproduction and mortality 



