| Alcidae () |
| 23 cm TL (male/unsexed); max.weight: 188.0 g |
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others; marine; depth range 0 - 43 m |
| Northwest and Eastern Pacific: From Aleutian Islands, Alaska, east to Canada and USA and south to Baja California, Mexico. Polar to subtropical. |
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Culmen: 1.92 cm; tarsus: 2.66 cm; wing: 14.8 cm. |
| Total Length: 20 to 23 cm (Ref. 8812). Relatively small bird with sperm-storage glands that allows delayed fertilization (Ref. 87784). Found along the continental shelf; <150 km. Exhibits plunge diving behavior (Ref. 356). Relatively small bird. Based on stable isotope analysis (SIA) diet study of egg albumin, belongs to lower N signature group (based on ratios of stable isotopes of nitrogen and carbon) indicating a more planktivorous diet, indicative of more pelagic foraging range. Copulation occurring ashore and ovum fertilization happens at sea; delayed fertilization possible because of sperm-storage glands; allows birds to feed at sea while egg forms and prior to the long period of fasting during egg incubation. Yolk formation occurs at sea where daily yolk deposition rapidly increases to a sharp peak. Double-brooded and can raise two broods annually. Reproductive success may be linked to long duration of pair bonds. Nest is usurped by the larger Pigeon Guillemot (Cepphus columba) and Rhinoceros Auklet (Cerorhinca monocerata) by the destruction of its eggs and chicks. ENSO event of 1982-1983 saw absence of returning birds to Farallon Is. In central California to breed, possibly due to the death of many older breeders. Reduced breeding rates and clutch size are the identified sublethal effects of exposure to oil from spill accidents (Ref. 87784). |
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Near Threatened (NT); Date assessed: 28 August 2020 (A2abce+3bce+4abce) Ref. 123251)
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