Semper's Warbler Leucopeza semperi Scientific name definitions

Jon Curson
Version: 1.0 — Published March 4, 2020
Text last updated June 5, 2015

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Introduction

Semper’s Warbler is endemic to the Caribbean Island of St. Lucia in the Lesser Antilles. It is possibly extinct as the last certain report comes from 1961. There have been some more recent observations but these have not been verified. This relatively large and bulky warbler was presumed to be a ground dweller. It has a long and spike-like dark bill and long pale legs and feet. Its plumage was subdued, grayish brown on the face, upperparts, wings and tail lacking wingbars or other obvious features; however the underparts were clean from the throat to the undertail coverts, although the flanks were grayish. Nearly nothing is known about the life history of this species. It is hypothesized that its decline was partly caused by the introduction of mongoose to the island in the late 1800's, although habitat alteration or other unknown factors may also be to blame.

Field Identification

14·5 cm. Dull parulid with long, deep-based and rather pointed bill. Has dark grey head and upperparts, with paler superciliary, browner wing and tail; whitish below, extensive grey-brown wash on side of breast and flanks; iris dark; bill dark greyish-horn, dull pinkish over most of lower mandible; legs dusky pinkish. Sexes alike. Juvenile undescribed; first-year browner above, washed pale buff below.

Systematics History

Monotypic.

Subspecies

Monotypic.

Distribution

St Lucia, in Lesser Antilles; no certain records since 1961.

Habitat

Lower montane and montane rainforests and elfin woodland with undisturbed understorey.

Movement

Sedentary.

Diet and Foraging

Virtually no information. Apparently forages in dense understorey, usually close to ground; possibly largely terrestrial.

Sounds and Vocal Behavior

Song undescribed. Only documented calls are a soft "tuck-tick-tick-tuck" and a chattering uttered when bird is alarmed.

Breeding

No definite information. Thought to nest on or near ground.

CRITICALLY ENDANGERED. Restricted-range species: present in Lesser Antilles EBA. Not certainly recorded since 1961, despite extensive searches. Unconfirmed, but probably reliable, sightings in May 1989 at Gros Piton (possibly involving two individuals), Sept 1995 at Piton Flore, and in 2003; a previously published sight record, from roadside at Barre de l'Isle, in Feb 1972, no longer considered valid. May have been locally common in 19th century but became excessively rare in 20th century, with only five certain records since 1920s, all from Barre de l'Isle ridge between Piton Flore and Piton Canaries. Despite destruction and degradation of habitat, suitable forest still exists on St Lucia, and the species' decline to probable extinction is thought to have been due to nest predation by small Indian mongoose (Herpestes auropunctatus), introduced on St Lucia in 1884 to control fer-de-lance snakes (Bothrops carribaeus). These snakes, however, were still common in Piton Flore area until at least 1960s, indicating that mongooses may have been rare in the warbler's last stronghold and therefore perhaps not sole culprits, habitat destruction or other unknown factors playing a part. With some unexplored montane or elfin forest habitat remaining in less accessible areas, there is a need for exhaustive surveys to locate any remaining population.

Distribution of the Semper's Warbler - Range Map
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Distribution of the Semper's Warbler

Recommended Citation

Curson, J. (2020). Semper's Warbler (Leucopeza semperi), 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.semwar1.01
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