California Current Science Plan Table 13

Table 13. Percent numerical contribution of euphausiids to auklet diets and auklet breeding productivity at the Farallon Islands, 1971-1990.

Category \Year | 1971* | 1977 | 1979 | 1980 | 1981 | 1985 | 1986 | 1987 | 1988 | 1989 | 1990
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Percent Euphausiids | 22 | 99 | 66 | 46 | 82 | 92 | 95 | 96 | 97 | 98 | 94
Percent T. spinifera | major | 85 | 68 | 6 | 55 | 22 | 27 | 43 | 37 | 37 | 22
Percent E. pacifica | --- | 15 | 32 | 75 | 40 | 70 | 62 | 53 | 60 | 61 | 58
Auklet chicks produced/pair | 0.8 | 0.9 | 1.1 | 0.6 | 0.7 | 0.7 | 0.7 | 0.7 | 1.1 | 0.6 | 0.4
Anomaly of mean chick weights, percent | +5 | +1 | 0 | -3 | +2 | -3 | -3 | +10 | -4 | 0 | +5

* Data for 1971 from Manual (1974), who presented data on the proportion of euphausiids in the diet and stated that T. spinifera was the "major" euphausiid species. No data on diet for 1972-76 and 1982-84; see Ainley and Boekelheide (1990) for auklet productivity in those years.

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