Green-backed firecrown

The green-backed firecrown ("Sephanoides sephaniodes") is a hummingbird that is found in Argentina and Chile. It is an important pollinator for the temperate rainforest regions of southern South America. It can be fairly common in some locations, especially on Robinson Crusoe Island, miles off the Chilean coast. It can be found in the Chilean matorral ecoregion, extending as far south as Tierra del Fuego.
Like its cousin the Juan Fernández firecrown, the green-backed firecrown often hangs from flower petals or leaves with its feet. Their nests are built in high branches or bushes. It exploits various flowers for nectar, and is able to recall not only the nectar location among identical flowers but also to the location of the most rewarding nectar among less rewarding flowers.
Much of the life history of the green-backed firecrown is unknown, including details of its migratory behavior, population dynamics, and pollination activities in the rainforests of southern South America. The species is sexually dimorphic, with large, short-billed males, and smaller, longer-billed females. Young green-backed firecrowns are sexually monochromatic, which makes it difficult to assign a sex to them.