As reported in U.S. Fish and Wildlife Service (and NYT)
"....4 million murres—half of Alaska's population—starved to death during the marine heatwave (2014).
The die-off was four to eight times larger than initially estimated, making it the largest single-species wildlife mortality event ever documented in modern history."
my note: for a singular specie, the common murre. A few years ago at least one billion sea creatures of various species cooked/died in the massive heat wave enveloping the beaches of the Pacific NW in the USA - I believe another billion or so died in the equally mild climate of the Canadian province to the north, BC.
For more on bird extinction and effects of climage change and ecological collapse in Alaska- read my novel Flight of the Goose: a Story of the Far North
