Dieta del correlimos diminuto (calidris minutilla) en cultivos de arroz orgánico de Colombia

Rice is one of the most important food sources for humans, and its global cultivated surface reaches ten millions of hectares. Many natural ecosystems, especially wetlands, have been modified or destroyed due to conversion to rice fields. However, rice crops require flooding, and the wetlands thus created can provide food for several organisms including shorebirds. In the organic rice fields of Valle del Cauca, in Colombia, twelve species of Nearctic migrant shorebirds have been recorded, including the highest numbers of Least Sandpipers (Calidris minutilla) in Colombia. On their breeding grounds in North America, Least Sandpipers feed on benthic and terrestrial invertebrates, while on the wintering grounds they ingest a wider range of prey. To determine the diet of Least Sandpipers in this type of cultivation in Valle del Cauca, from October 2012 to December 2012 we caught 50 individuals using mist netting and obtained regurgitates induced with saline solution. The identification of prey found in regurgitates indicates that Least Sandpipers feed on insects, spiders, and vegetable material in the study site. In addition, they use small stones to crush prey with hard exoskeleton, such as Coleoptera and Hemiptera. Given the relatively high levels of consumption of beetle larvae and adults, which are considered pests for rice crops, Least Sandpipers could be one of the main biocontrol agents of these insects. This information contributes to understand why Least Sandpipers use organic rice fields and highlights the importance of this agroecosystem for the migration of this shorebird.