Historical (1960 - 2011) and spatial analysis of mercury and arsenic in two species of tropical birds in southeastern Mexico.

Spatiotemporal variation in the concentrations of mercury (Hg) and arsenic (As) in body feathers of Red-throated Ant-Tanager (Driophlox fuscicauda) and Clay-colored thrush (Turdus grayi) were evaluated. Body feathers were obtained from scientific collections (specimens collected from 1960 to 2011) in Mexico. Trace elements concentrations were determined by voltammetry through acid digestion.

[Hummingbird abundance and flowers use in a template forest from Southeast Mexico].

Hummingbird abundance varies with plant bloom phenology used for feeding. However, the information on hummingbird-flower interaction is limited for tropical mountain environments. We evaluated hummingbird abundance using mist nest and estimated monthly flowering phenology visited by hummingbirds in three different habitats (oak forest, cloud forest and bush) from January to August 2010 in Huitepec Ecological Reserve.