Testing for sentinel coordination in Smooth-billed Anis (Crotophaga ani)

Sentinel behaviour has been widely described, but whether or not it is coordinated among group members requires careful examination. The Smooth-billed Ani, Crotophaga ani, a joint-nesting cooperatively breeding bird, appears to have a sentinel system; however, it is unknown whether that vigilance is coordinated, the defining feature of sentinel behaviour. We followed social groups during two breeding seasons to observe and time their individual …