Effect and Efficiency of Tartar Emetic in Determining the Diet of Tropical Land Birds

The effect and effectiveness of tartar emetic was tested on 82 bird species from 25 families and subfamilies inhabiting seasonal habitats of northeastern Venezuela. Of the 3,419 birds forced to regurgitate, 3,033 diet samples were obtained and 2,712 of them had recognizable food. Seventy birds (2%) died after administration of the chemical, but a smaller dosage or concentration reduced mortality in species more sensitive to the emetic. Overall, 24 invertebrate taxa and 59 fruit species were identified, with an average of 6 items per sample. Pollen grains were observed in 55% of the samples from nectarivorous species. Considering the low mortality, as well as the diversity of prey types and sizes found in samples, regurgitation using tartar emetic is probably the best method for determining the diet of land birds from various feeding habits.