Black-necked stilts (Himantopus mexicanus) are American shorebirds with long thin legs, slim wings, and a needle-like bill. They primarily feed on insects or crustaceans that they scoop out of water or air. They are social birds that nest together in colonies. When their nests are threatened, these birds may participate in a “popcorn display,” grouping around a predator and jumping or flapping their wings at it in an attempt to drive it away. You can find them in environments with shallow water, like mudflats, salt pans, and salt marshes.
Sources: Black-necked Stilt–audobon.org, Black-necked Stilt Identification–All About Birds, and Black-necked Stilt–Wikipedia
Photos: _Veit_ on Flickr