Dietary relationships among four granivorous doves in Venezuelan savannas

Abstract

A total of 537 crops from four coexisting granivorous doves (Columbina minuta, C. passerina, C. talpacoti and Scardafella squammata), collected on seven sampling dates in a Venezuelan savanna, were examined to assess food partitioning. These closely related doves are resident birds, and overlap broadly both in daily activity patterns and habitat use; in circumstances like this, segregation in the use of food resources often occurs. It was found that: (a) differences in body dimensions did not account for variations in seed size taken by doves; they all ate seeds in the same size range and they showed high similarity in seed size preferred; (b) the importance of different seed sizes in the diets changed seasonally with similar tendencies for all four species, (c) there were differences up to 4-fold in mean seed size consumed by individuals of the same species on the same date; (d) seeds of 63 plant species were consumed by the four dove species and constituted from 98 to 99.5% of the diets; (e) high dietary overlap both in prey size and prey type was found throughout the year. The dietary relationships found in this study support the idea that these birds forage opportunistically, and that some differences found among their diets may be the result of random seed sampling from the heterogeneous seed pool available.