Meeting Abstract
Identifying the barriers that prevent gene flow between closely related species is a fundamental goal in evolutionary biology. A potential reproductive isolating barrier that has not yet been tested is cognitive ability. Cognitive traits, such as spatial memory and learning ability, are important for fitness in food-caching birds, where accurate cache retrieval is crucial for survival in harsh environmental conditions. Here, we compare the spatial memory and learning ability between two North American species of food-caching songbirds and their naturally occurring hybrids (Black-capped chickadees, Carolina chickadees, and hybrid chickadees). We hypothesize that hybrid chickadees will be cognitively deficient relative to pure species individuals. To test this hypothesis, we subjected wild-caught black-capped (Poecile atricapillus), Carolina (P. carolinensis), and hybrid chickadees to a set of behavioral experiments designed to test cognitive ability in an outdoor aviary setting. Our preliminary results suggest that hybrid chickadees perform worse on spatial memory tasks and novel problem-solving tests than pure species individuals. These experiments suggest that impaired cognition may function as a source of selection against hybrids in nature, and may contribute to maintaining reproductive isolation between chickadee species.
