Predator Vocalizations Affect Foraging Trade-offs of Northern Cardinals

• Published in: The Wilson journal of ornithology 2010-03, Vol.122 (1), p.168-173
• Main Authors: Stanback, Mark T., Powell, Emily M.
• Format: Article
• Language: English
• Subjects: Accipiter; Animal behavior; Animal feeding behavior; Bird songs; Birds; Birds of prey; Cardinalis cardinalis; Evolutionary psychology; Experiments; Feeding; Food; Food quality; Foraging; Foraging (Animal feeding behavior); Foraging behavior; Hawks; Helianthus; Northern cardinal; Perception; Place preferences; Predation; Predation (Biology); Predators; Seeds; Short Communications; Sunflower seeds; Vocalization behavior; Wild birds
• ISSN: 1559-4491; 1938-5447
• DOI: 10.1676/09-052.1

We investigated the roles of food quality and predator avoidance in shaping foraging behavior of Northern Cardinals (Cardinalis cardinalis). Cardinals visited feeders near cover and feeders with sunflower seed significantly more than they visited those in the open and those with commercial wild bird seed mix. Cardinals with a choice between their preferred food and preferred location visited the sunflower seed feeder in the open significantly more than the mixed seed feeder near cover, despite their prior preference for feeding near cover. We recorded visits to these feeders over a 2-day period during which we played Cooper's Hawk (Accipiter cooperi) calls every 2 hrs. The overall visitation rate did not decrease significantly, nor did the visitation rate to feeders near cover increase significantly. However, the decrease in the visitation rate to feeders in the open approached significance. Overall, we observed a significant shift in the proportion of visits to feeders near cover (containing less preferred seed). We conclude Northern Cardinals are sensitive to both food quality and predation risk, and adjust foraging to prevailing perceptions of risk.