Figure 1. Dummies used in experiments showed all combinations of two hypothesized recognition cues (yellow eyes, barred underparts).

Presence (+) and absence (−) of hypothesized recognition cues (yellow eyes/barred underparts) on particular dummies: (a) natural cuckoo (+/+), (b) natural dove (−/−), (c) cuckoo-dove (+/−), (d) dove-cuckoo (−/+), (e) black-eyed cuckoo (−/+). Dummies (c–e) were custom-designed for this study. All dummies were natural stuffed dummies (i.e., not artificially painted) in a life-like perching position similar to positions showed by cuckoos visiting host nests. Legs of dummies are not shown in this figure to save space and for visual simplicity.