Juan Fernández Firecrown

The Juan Fernández firecrown (''Sephanoides fernandensis'') is a Critically Endangered hummingbird in the "coquettes", tribe Lesbiini of subfamily Lesbiinae. It is endemic to Isla Róbinson Crusoe, one of the three-island Juan Fernández archipelago belonging to Chile.HBW and BirdLife International (2020) ''Handbook of the Birds of the World and BirdLife International digital checklist of the birds of the world'' Version 5. Available at: http://datazone.birdlife.org/userfiles/file/Species/Taxonomy/HBW-BirdLife_Checklist_v5_Dec20.zip xls zipped 1 MBretrieved May 27, 2021

Taxonomy and systematics

The Juan Fernández firecrown shares genus ''Sephanoides'' with the green-backed firecrown (''S. sephaniodes''). It has one existing subspecies, the nominate ''S. f. fernandensis''. Most worldwide taxonomic systems attribute a second subspecies to it, the extinct ''S. f. leyboldi''. They list it as having occurred on another island in the Juan Fernández group, Alejandro Selkirk Island (also called Más Afuera).Clements, J. F., T. S. Schulenberg, M. J. Iliff, S. M. Billerman, T. A. Fredericks, J. A. Gerbracht, D. Lepage, B. L. Sullivan, and C. L. Wood. 2021. The eBird/Clements checklist of Birds of the World: v2021. Downloaded from https://www.birds.cornell.edu/clementschecklist/download/ Retrieved August 25, 2021 However, at least one author questions the two-subspecies treatment and whether a firecrown ever inhabited Selkirk.Johow, Federico. (2007). El picaflor de la Isla de Masafuera: ¿subspecie extinta, nunca existió o mistery bird? / The Hummingbird of the Masafuera Island: extinct subspecies, never existed or Mystery Bird? Boletín Chileno de Ornitología 13: 28-41. n Spanish with English summary/ref>

Description

The Juan Fernández firecrown is among the most radically sexually dimorphic hummingbirds. The male and female plumages are so different, and even the female has a male-like iridescent crown, that in the 19th century they were thought to be different species until a nest was discovered with one of each sex. Males are long and weigh about . Females are about long and weigh about . Both sexes have a straight black bill.Roy, M.S., G. M. Kirwan, and P. F. D. Boesman (2020). Juan Fernandez Firecrown (''Sephanoides fernandensis''), version 1.0. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.juffir1.01 retrieved July 25, 2022

The male is almost entirely cinnamon-orange. Its forehead and crown are iridescent fiery reddish yellow and the wings dark coppery gray. The female's upperparts are bluish green with an iridescent bluish purple crown. Its underparts are pure white with black and green disks and the wings slaty green. The central tail feathers and the inner webs of the others are blue-green and the outer webs white.

Distribution and habitat

The nominate subspecies of Juan Fernández firecrown is found only on Isla Róbinson Crusoe. The putative extinct subspecies ''S. f. leyboldi'' is attributed to Alejandro Selkirk Island.
The species inhabits forests, thickets, and gardens, favoring shady areas. In summer, males are frequently seen in the island's only town, San Juan Bautista, feeding on the flowers of trees of genus ''Dendroseris'' which are endemic to the island chain, and many of which are themselves critically endangered species. All of the breeding records are at elevations between .

Behavior

Movement

The Juan Fernández firecrown moves around the island, presumably in search of flowering plants, but is otherwise sedentary.

Feeding

The Juan Fernández firecrown forages for nectar at the flowers of native plants, especially ''Rhaphithamnus venustus'' and ''Dendroseris litoralis''. It may also feed on introduced '' Eucalyptus'' and ''Abutilon'' trees. The clutch size is two eggs. The incubation period and time to fledging are not known.

Vocalization

The Juan Fernández firecrown's song is "a medley of high-pitched squeaky notes, dry gravelly trills and descending chatters."

Status and conservation

The IUCN has assessed the Juan Fernández firecrown as Critically Endangered. The species inhabits only one small island. It has an estimated population of 1500 to 3500 mature birds or 3000 to 5200 total individuals and the number is believed to be decreasing. The destruction of native trees, which the species depends on for nest sites, is a major cause of the decline. Also contributing are the spread of exotic zarzamora blackberry ('' Rubus ulmifolius'') and maqui wineberry (''Aristotelia chilensis''), predation by domestic and feral cats, and destruction by introduced rabbits and goats. It may also suffer from competition for food from the more numerous green-backed firecrown.

A conservation effort was begun in 2004 by a partnership of several organizations (The Hummingbird Society, American Bird Conservancy, and Juan Fernández Islands Conservancy, Oikonos - Ecosystem Knowledge) with the aim of preventing extinction of the species. Their efforts include planting native species, removing non-native plants, and reducing non-native predators and competitors. Island residents have been hired as project coordinators and workers.

References

External links

Conservation research on the Juan Fernandez Islands.Island Conservation Restoration Project

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Juan Fernández firecrown
Endemic fauna of the Juan Fernández Islands
Birds of Chile
Robinson Crusoe Island
Critically endangered animals
Critically endangered biota of South America
Endemic birds of Chile
Juan Fernández firecrown