Food of Flesh-footed Shearwaters Puffinus carneipes Associated with High-seas Driftnets in the Central North Pacific Ocean

Abstract

We examined digestive tract contents and stable nitrogen isotope ratios in breast muscles of Flesh-footed ShearwatersPuffinus carneipesassociated with high-seas driftnet fisheries in the central North Pacific Ocean. Small fish, Lanternfish (Myctophidae) and Pacific Saury Cololabis saira, were the principal prey found in the digestive tracts. Pieces of unidentified fish, possibly Pacific Pomfret Brama japonica, and shredded squid tissue, mostly Neon Flying Squid Ommastrephes bartrami, in the digestive tracts indicate scavenging at driftnet fishing operations. Although soft-bodied animals such as Velella sp. were rare in the digestive tracts, low stable nitrogen isotope values (δ¹⁵ N) suggest Flesh-footed Shearwaters feed heavily on such low trophic level animals.