Little Blue Heron (Egretta caerulea) Science Article 6
Experiments using model herons in natural mangrove habitats demonstrated that more hawks are attracted to white than to blue herons. Both Common Black-Hawks (Buteogalluas nthracinus) and crocodiles (Crocodylus acutus) were observed preying on adult herons in Panama. Solitary herons were at greater risk than flocked foragers. White (immature) Little Blue Herons (Egretta caerulea) were attacked more frequently by hawks than were the blue adults of their species. Dark herons gave more alarms than white herons. Although flock size decreased in years of heavy predation and after attacks, mixed-flock composition remained the same.
GLORIA S. CALDWELL, The Auk 103: 494-505