Habitat use, diet and breeding biology of tufted puffins in Prince William Sound, Alaska

Habitat use, diet and breeding biology of tufted puffins (Fratercula cirrhata) were studied in Prince William Sound, Alaska, during summer 1995. On Seal Island, 112 puffin burrows (71% active) were located. Of 95 accessible burrows, 49% were typical earthen burrows, whereas the remainder were atypical for the species (e.g., under tree roots). Hatching success (≤79%), fledging success (≥82%), chick growth rates (17.7 g/day), asymptotic (600 g) and fledging (563 g) weights, meal sizes (14.2 g), meal delivery rates (5.32 meals/day), and daily rations (75.5 g/day) were all average or above-average for tufted puffins in Alaska. A total of 42 chick meals, comprising 125 individual prey were collected. Meals were composed of juvenile pollock (12.7% of total mass), herring (21.8%), prowfish (32.3%), salmonids (24.1%), and capelin, sandlance and squid (<5% each). Tufted puffin populations in Prince William Sound are relatively small, and may be limited by low densities of prey in the Sound, nest-site availability, and heavy rainfall.