Behavioral observations on the White-breasted Thrasher (Ramphocinclus brachyurus brachyurus): conservation implications

摘要

The White-breasted Thrasher (Ramphocinclus brachyurus brachyurus) is surviving at the tip of the Caravelle peninsula in Martinique, on a 5 km(2) territory. Once widespread throughout the island, this passerine was on the verge of extinction in the 1950s but managed to recover. The creation of the Caravelle Nature Reserve in 1976 contributed to the protection of its habitat, but little is known about the factors behind the slow population growth registered in the past decades. A year-long ethological study was launched by the Regional Natural Park of Martinique (PNRM) in order to understand the status of this endangered species. In spite of some limitations, original observations shed new light on the behavior of this endemic species. New calls and a song were identified for the White-breasted Thrasher. The study highlights seasonal variations in the bird's feeding behaviors and some behavioral plasticity in its reproductive strategies. Individuals appear to be exposed to strong predation pressure, especially during the breeding season. The confirmation of the modus operandi of rats against White-breasted Thrashers' nests should help improve the conservation policy of this bird.