Ortiz-Pulido, R., A. T. Peterson, M. B. Robbins, R. Díaz, A. G. Navarro y G. Escalona-Segura. 2002. The mexican Sheartail (Doricha eliza): Morphology, behavior, distribution, and endangered status. Wilson Bulletin 114: 153-160.
We reviewed morphological variation, taxonomic status, geographic distribution, ecology, and behavior of the poorly known hummingbird, the Mexican Sheartail (Doricha eliza), based on museum specimens and field studies. Although the broadly disjunct distribution of the species would suggest that two taxa are involved, morphological differences between the populations appear minor, not deserving of formal taxonomic recognition. Ecological differences between the two populations are stronger, however; modeled ecological niches are nearly nonoverlapping, and ontogenetic and behavioral differences may exist. We recommend that, given its extremely restricted distribution, the Veracruz population be considered critically endangered, whereas the Yucatan population be designated as having a restricted range and accorded near-threatened status.