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

Jean-Raphael Gros-Desormeaux,Thierry Lesales,Alexis-Georges Tayalay

doi:10.1007/s10211-014-0207-3

Jean-Raphael Gros-Desormeaux, Thierry Lesales + Show 1 more

Open Access

https://doi.org/10.1007/s10211-014-0207-3

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Abstract

The White-breasted Thrasher (Ramphocinclus brachyurus brachyurus) is surviving at the tip of the Caravelle peninsula in Martinique, on a 5 km2 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.

Highlights

With about 12,500 vertebrate and plant species, the Caribbean Islands Hotspot is one of the world’s greatest centers for biodiversity and endemism
The homogeneity test conducted in the time series of each elementary unit of action from the behavior information system found a significant variation in the analysis of the following time series: classic foraging; perched; foraging and singing; trembling wings, shaking, and pecking a leaf or pecking a twig; nest building; perched on the nest; lying in a nest; type [Gnok] call; type [Chee-ka] call; complex call type; and type [Tseeep] call (Fig. 4)
The R. b. brachyurus was often observed engaging in behaviors related to feeding on leaf litter on the ground [frequency 80 %; n=246]

Summary

Introduction

With about 12,500 vertebrate and plant species, the Caribbean Islands Hotspot is one of the world’s greatest centers for biodiversity and endemism. Five hundred sixty-four birds are present, of which 26 % are endemic (CEPF 2009). The White-breasted Thrasher (Ramphocinclus brachyurus), is found only in the Lesser Antilles islands Martinique and St. Lucia. With a total population estimated at 1,900 individuals and given its highly restricted range, it is ranked as “endangered” (IUCN 2012). Recent and ongoing studies on the declining population of the St. Lucia White-breasted Thrasher (Ramphocinclus brachyurus sanctaeluciae) have greatly improved the scientific knowledge of the behavior and the threats that this species faces. The Martinique White-Breasted Thrasher appears to be less known than the St. Lucia subspecies

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