Foraging behavior of migratory shorebirds during non-breeding periods in the Americas: a review

Optimizing foraging strategies for searching and handling food could be decisive in the survival of migratory shorebirds, which depend on the food supply they find at their stopover sites. Shorebirds are opportunistic feeders that can exhibit inter- and intraspecific variations in foraging behavior associated with bill morphology, the type of prey to be captured, and the type of substrate to be explored. Few studies describe the feeding behaviors of migratory shorebirds in the Americas, so complementation is still required. Through a systematic review of Scopus, Web of Science, and SciELO databases, we analyzed papers published from 1989 to 2021 that investigate the migratory shorebirds' feeding behaviors in their non-breeding areas in the Americas. We considered 31 articles with 14 descriptions of behaviors. We found that 11 out of 35 species have not yet been studied in this area of ecology and none have been studied on the Pacific coast of South America or on the mid-continental route that crosses the Amazon region. The shorebirds with the highest reported behaviors are Arenaria interpres and Calidris minutilla. Pecking and probing are the most common behaviors in Charadriidae and Scolopacidae families. The rest of the behaviors can likely be extrapolated to other species of the genus; however, it is necessary to expand studies in this field of animal behavior by applying new technologies and including other stopover sites. Unfortunately, many shorebird species in the Western Hemisphere exhibit population declines and understanding the use of these food resources can help guide conservation and responsible development decisions.