The bird mistook the plastics for food

http://www.mindfully.org/Plastic/Ocean/Moore-Trashed-PacificNov03.htm
http://www.mindfully.org/Plastic/Ocean/Moore-Trashed-PacificNov03a.jpg

"Bottle caps and other plastic objects are visible inside the decomposed carcass of this Laysan albatross on Kure Atoll, which lies in a remote and virtually uninhabited region of the North Pacific. The bird probably mistook the plastics for food and ingested them while foraging for prey."