Tiny, highly endangered hummingbird found very locally in the desert of northern Chile. Favors native desert scrub in lowland valleys, but widely eliminated from most areas by intensive agriculture. Male most often detected by insectlike buzz made by wings in flight. Also perches conspicuously atop bushes and on wires; note diagnostic crossed tail feathers. Female similar to Peruvian Sheartail, but has shorter tail with pale rusty bases to outer feathers (hard to see).