Elegant, slender bird of open country, frequently seen in flight or perched on exposed snags or telephone wires. Adult green overall, with blue tail, thin black mask, and rufous throat; bright rufous underwings visible in flight. Juvenile similar but paler, with tannish throat and shorter tail, lacking the adult's elongated central tail feathers. Flying bird has distinctive shape, with broad, sharply pointed wings, long tail, and long bill. Nests colonially in sandbanks. Voice a sweet, clipped “cheer-it,” sometimes given in series.