Distribution, ecology and conservation of an endangered Andean hummingbird: the Violet-throated Metaltail (Metallura baroni)

The Violet-throated Metaltail Metallura baroni is a high altitude hummingbird endemic to south-central Ecuador currently considered globally 'Endangered'. Here we present the first detailed assessment of its distribution, ecology and conservation. We first used a maximum entropy model (Maxent model) to create a predicted distribution for this species based on very limited species occurrence data. We used this model to guide field surveys for the species between April and October 2006. We found a positive relationship between model values and species presence, indicating that the model was a useful tool to predict species occurrence and guide exploration. In the sites where the metaltail was found we gathered data on its habitat requirements, food resources and behaviour. Our results indicate that Violet-throated Metaltail is restricted to the Western Cordillera of the Andes Mountains in Azuay and Canar provinces of Ecuador, with an area of extent of less than 2,000 km(2). Deep river canyons to the north and south, lack of suitable habitat, and potential interspecific competition in the east may limit the bird's distribution. The species occurred in three distinct habitats, including Polylepis woodland, the upper edge of the montane forest, and in shrubby paramo, but we found no difference in relative abundance among these habitats. The metaltail seems to tolerate moderate human intervention in its habitats as long as some native brushy cover is maintained, We found that Brachyotum sp., Berberis sp., and Barnadesia sp. were important nectar resources. The 'Endangered' status of this species is supported due to its restricted distribution in fragmented habitats which are under increasing human pressures.