The Black-chinned Hummingbird (Archilochus alexandri) is a small hummingbird. It is an extremely adaptable bird, occupying a broad range of habitats.
The black-chinned hummingbird is 3.25 in long. Adults are metallic green above and white below with green flanks. Their bill is long, straight and very slender. The adult male has a black face and chin, a glossy purple throat band and a dark forked tail. The female has a dark rounded tail with white tips and no throat patch; they are similar to female ruby-throated hummingbirds.
As of 2011, it has the smallest known genome of all living amniotes, only 0.91 pg (910 million base pairs).