The diet of the Southern Giant Petrel in Patagonia: fishery-related items and natural prey

COPELLO, S, QUINTANA, F Y PEREZ, F.

Endagered Species Research

Inter-Research

Año: 2008 vol. 6 p. 15 - 23

1863-5407

There is an increasing interest in dietary composition of threatened seabirds as an importantkey to understanding their feeding ecology, population dynamics and interaction with fisheries.Several seabird species exploit discards from fisheries as their main food. The southern giant petrelMacronectes giganteus is a wide-ranging procellariform. It is considered a near-threatened species under International Union for Conservation of Nature (IUCN) criteria and has been included as athreatened species in the Appendix 2 of the Convention on the Conservation of Migratory Species ofWild Animals. The diet of Patagonian colonies of this species remains unknown, even though understandingthe relationship between southern giant petrels and fisheries may be crucial to the conservationof this species in the Southwestern Atlantic. We describe the diet of the southern giant petrel fromnorth Patagonian colonies using chick regurgitations and evaluate its relationships with the fisheries.Carrion occurred in the diets of 90.8% of birds sampled, while cephalopods occurred in the diets of65.1%. Crustaceans were present in 43.7% of samples and fishes in 19.4%. Anthropogenic items werefound in 72.7% of the samples. The presence in the petrel s diet of target and discarded species fromfishery vessels, and the high incidence of marine debris, suggests an extensive use of discard over thePatagonian Shelf.