Seidenkuhstärling Molothrus bonariensis

Common in Caribbean and South America. Found in semiopen and open grassy areas, often associated with livestock. Feeds mainly on the ground, but perches readily in bushes and trees. Male is glossy blue-black overall (often looks simply black). Female is plain grayish-brown overall. Bill shape is the key feature: blackish bill is more slender and pointed than bills of Brown-headed and Bronzed cowbirds. Also note similar but larger Melodious Blackbird, which has longer bill and often flicks its tail.