predator because there is an advantage to seeing the predator first. There is also the risk that in a bigger group there will more false alarm signals. The common signal is vocalization, after which the birds will fly up into the trees. It was found the birds did not however give this signal when there was a snake. References Further reading External links BirdLife Species Factsheet Guianan cock-of-the-rock Birds of Colombia Birds of Venezuela Birds of the Guianas Guianan cock-of-the-rock Guianan cock-of-the-rock