Endangered
Elfin Woods Warbler
Setophaga angelae
The elfin woods warbler is a bird endemic to Puerto Rico, where it is local and uncommon.
Appearance
Its upperparts are predominantly black with white areas, and its underparts are white with black streaks. Other identifying characteristics are dark brown eyes, white patches on its ears and neck, an incomplete white eyering, a white eyestripe, and two white spots on its outer tail feathers. Like other Antillean warblers (Adelaide's warbler, Saint Lucia warbler, plumbeous warbler, and arrowhead warbler), it has a long bill and short, round wings (53.8 mm or 2.12 in average).
The elfin woods warbler is a small passerine, averaging 12.5 cm (5 in) in length and 8.4 g (0.30 oz) in weight. Among Setophaga species, only Adelaide's warbler has a shorter average wing length.
Published measurements include mass about 8.4.
Discovered in 1968 and described in 1972, it is the most recently described New World warbler (family Parulidae).
Range and habitat
When first discovered, the elfin woods warbler was believed to exclusively occur in the high elevation, from 640 to 1,030 meters (2,100 to 3,380 ft), dwarf or elfin forests of the El Yunque National Forest in eastern Puerto Rico. The wind-clipped trees in these forests rarely exceed 5 meters (16 ft) in height and are characterized by stiff, thick twigs, leathery leaves and impenetrable, dense undergrowth ideal for hiding from predators. Later studies showed that the species migrated to lower elevations, between 370 and 600 meters (1,210 and 1,970 ft), in Tabonuco and Palo Colorado forests.
Pins are Wikidata “endemic to” fields. Orange dots, when present, are GBIF occurrence tiles — survey bias included.
Diet and breeding
The elfin woods warbler is commonly found foraging the middle canopy for insects. Three maneuvers used for catching prey—gleaning, sally-hovering and probing—have been described.
Probing is a maneuver in that the bird, by digging with its beak, forages the substrate looking for food in a manner similar to chickens. The elfin woods warbler breeds from March to June. Both parents are involved in the construction of the nest and in feeding the chicks.
In crisis
Due to its small populations and restricted habitats, conservation efforts were begun in 1982 to protect this species, but as of 2005, the warbler was still in need of protection. The species is not in immediate danger as the majority of its habitat is protected forest, but introduced species (such as rats and small Asian mongooses), habitat reduction, and natural disasters represent potential threats to the population. In September 1989, Hurricane Hugo struck the central and eastern region of Puerto Rico, affecting three of the four known populations of the elfin woods warbler. The El Yunque National Forest, Toro Negro, and Carite populations were all impacted.
A survey conducted two years later in the Toro Negro Forest, located in the Cordillera Central, did not find any individuals. Surveys conducted since then suggest that, for reasons yet unknown, the populations at Carite and Toro Negro were likely extirpated.
Elfin Woods Warbler is Endangered on this catalog because that is the IUCN category stored on Wikidata. Confirm the official criteria and any later count on iucnredlist.org.
Sources
Written for this catalog from the English Wikipedia article on Elfin Woods Warbler, Wikidata item Q532125. Family and order context is original field-guide writing about the group, not a copied assessment of this one species. Wikipedia text is CC BY-SA. Not an IUCN assessment. Counts, when quoted, can change — confirm them on the recovery programme and on iucnredlist.org.
