Comparative day and night feeding strategies of shorebird species in a tropical environment

A study was carried out in northeastern Venezuela to determine whether or not shorebirds feed at night in tropical environments. Results show that some Neotropical residents and Nearctic winter migrants feed during darkness. During daylight, Black-winged Stilts Himantopus himantopus, mexicanus group, were predominantly visual foragers (75% attempts were pecking), performing a tactile type of feeding technique (immersion of the whole head and portion of the neck while searching for food through soft mud) on other occasions. During night-time, they were almost equally visual (pecking) and tactile (multiple scythelike sweeps) foragers. Greater and Lesser Yellowlegs Tringa melanoleuca and T. flavipes foraged visually during daylight and tactilely (sidesweeping) at night. Short-billed Dowitchers Limnodromus griseus were tactile feeders (probers) both by day and by night while Semipalmated Plovers Charadrius semipalmatus during daylight and at night and Wilson's Plovers C. tvilsonia by night were sight feeders (peckers). Prey abundance was higher at night than during daylight. Black-winged Stilts and yellowlegs seemed to feed at night on food items at least partly different from those they fed upon during daylight.