Steller’s jays assess and communicate about predator risk using detection cues and identity

Predators can vary in the risk they pose, depending upon the factors such as body size, maneuverability, hunting strategy, and diet. Prey can also detect predators with different senses, such as seeing, hearing, or smelling them. We presented wild Steller’s jays (Cyanocitta stelleri annectens) with visual cues (robotic raptors) or acoustic cues (call playbacks) of 4 different raptors to test how they assess risk and how this influences their alarm calls. The assessment of risk from different predator cues varied with different species of raptors: Jays responded to sharp-shinned hawks (Accipiter striatus) with an increase in latency to resume foraging regardless of whether they were seen or heard, whereas latency responses to northern goshawks (Accipiter gentilis) were longer if they were seen versus if they were heard. Furthermore, Steller’s jays altered the acoustic structure of their alarm calls depending on the species of raptor and whether they saw or heard them. These results demon...