http://www.slate.com/articles/health_and_science/science/2015/01/mass_bird_deaths_explained_why_birds_sometimes_die_in_groups_video.html

More than 1,200 dead seabirds have washed ashore off Washington state and northern California in recent months, the latest large-scale bird deaths to capture headlines. These cases tend to invite speculative (and sometimes conspiratorial) theories, but no matter the cause of death, there’s actually a simple reason behind them. The video above explains the trends behind mass bird deaths in North America and beyond.