Visual cue preference in Chimango

Abstract

Chimangos were captured using walk-in traps across an urbanization gradient (n=31: 8 urban, 10 suburban, 13 rural) in southeastern Buenos Aires Province, Argentina, during the non-breeding season. Due to low male numbers, sex was excluded from analyses. Birds were housed individually in outdoor aviaries, habituated for ≥5 days with daily feeding (40–60g meat) and water ad libitum, before release post-experiments. The experimental protocol, adapted from established methods, used a 9-well grid with color and positional cues. Subjects underwent daily sessions (three 3-min trials) after ~18h fasting, with meat odor applied to all wells. Habituation involved nine rewards without lids until all were obtained. Pre-training required birds to remove colored lids (blue, black, white) from baited wells, with lids gradually covering wells; the criteria were meeting reward collection. Training comprised five sessions with a novel lid (yellow/green) marking one reward, maintaining a constant cue arrangement. A learning test (no reward) followed, presenting three lids: same color (correct color), same position (correct position), and a distractor, recording first/second choices and latency. Overtraining (three sessions of four trials over three days) included interspersed learning tests for 24 individuals, measuring changes in choice as a measure of behavioral flexibility. Latency was recorded during initial habituation and pre-training as a measure of neophobia.