Resumo

RODRIGUEZ-PARGA, Luz de los Milagros; CONTRERAS-MARTINEZ, Sarahy; ROST, Josep  e  GOMEZ-LAMAS, José Cruz. Seasonal abundance, reproductive phenology and site fidelity in riparian environments of the Blue Mockingbird (Melanotis caerulescens) in southwestern Jalisco. Rev. Mex. Biodiv. [online]. 2012, vol.83, n.2, pp.468-476. ISSN 2007-8706.

This study describes the seasonal abundance, reproductive phenology and site fidelity of the Blue Mockingbird (Melanotis caerulescens), an endemic species of Mexico noted for its singing capabilities. This species was sampled using mist-nets for 2 consecutive years at 3 sites of riparian vegetation in the Ayuquila River, Jalisco. Habitat characterization was carried out through sampling strata of trees, shrubs, and herbaceous ground cover. We used Generalized Linear Models to analyze the differences in coverage strata between the sites, and to identify the effect of site and month on the abundance of the species. The presence of a brood patch and/or cloaca protuberance characterized adults of respective sexes during the breeding season (April through August). Blue Mockingbird abundance was positively related to sites with greater shrub cover and the site fidelity analysis (individuals' presence or absence) showed that at least 3 breeding pairs maintained their territories in the study sites for the duration of the project. These results suggest that maintaining an adequate density of understory through shrub in riparian areas is important for providing food, cover and nesting areas for this species. This study is relevant because it is the first data published on this issue for this endemic species.

Palavras-chave : Melanotis caerulescens; shrub layer; breeding season; site fidelity.