The cost of limited attention in blue jays

Experiments with fish and birds suggest that animals are unable to simultan eously allocate sufficient attention to tasks such as the detection of an a pproaching predator while searching for cryptic prey. We quantified the eff ects of limited attention on performance in controlled laboratory settings and report here the first direct evidence that attending to a difficult cen tral task simulating foraging deters a bird's ability to detect a periphera l target, which could be a predator. Our results fill a gap between ecologi cal and neurobiological studies by illustrating that, although attention is an efficient filtering mechanism, limited attention may be a major cause o f mortality in nature.