I live on the water North of Topsail and the only thing that I can think of is that these birds were caught in someone's fishing nets. The only way to get their nets back in one piece is to shoot, kill then cut them out of the tangled mess. I too think that this is obsurd and not the norm for NC fishermen. I would suspect a single boat of rogue idiots. What they don't know or care about is the $1000 fine per bird since they are protected under the migratory foul protection act in NC. As to date, there has been over 145 Brown Pelicans that have washed ashore in New Hanover, Onslow, Craven, Carteret and Pamlico counties in North Carolina. Here's a link that you might want to see from WITN News...
The Pelican Brief