No Sex-Differences in Learning Trap-Gap Problems in Zebra Finches

Sex differences in cognition are often predicted based on ecological roles, particularly when one sex engages more extensively in specific behaviors that might be subject to selective pressure. In zebra finches (Taeniopygia guttata), males choose and deposit the majority of the material into the nest and might therefore exhibit enhanced physical cognition. We tested this hypothesis using the trap-gap task, a modified shape-frame matching paradigm designed to evaluate how animals assess object-hole relationships. In this task birds pulled food-containing trays attached to strings through gaps in barriers. Birds were trained on either a barrier task (choosing the correct gap size to fit a tray between barriers with different gaps) or a tray task (choosing the correct tray size between barriers with the same gap), then transferred to the alternate task (called the transfer test). Contrary to predictions, males and females showed no differences in the number of trials to reach learning criteria or in the number of errors in the transfer test. Birds required more trials, on average, to learn the barrier task compared to the tray task, and the transfer test was at chance, suggesting birds relied on absolute cue-based strategies rather than learning the object-gap relationship (relative cue-based strategies). These findings align with previous research showing no sex differences in learning about material properties in zebra finches, despite males' dominant role in nest building. The lack of sex differences in performance may stem from a mismatch in spatial frames of reference: while nest building relies on an egocentric (body-centered) frame, the trap-gap tasks uses an allocentric (object-centered) frame. Our findings highlight the complexity of linking behavioral sex roles to cognitive specialization and underscore the importance of task design and ecological relevance in comparative cognition research.