Kelly, J. P.
Managing wildlife is extremely difficult because natural processes that determine animal abundance and behavior are often complex and mysterious. Among the most mysterious are the influences of Common Ravens on nesting herons and egrets. Ravens occasionally prey on active heron and egret nests, but more typically, they are scavengers of failed nests and do not threaten the persistence of heronries. At most heronries, at least for now, managing the predatory activities of ravens is unnecessary. However, with raven populations growing rapidly in apparent response to the expansion of agriculture, roads, garbage dumps, and urbanization, questions have emerged about potential increases in raven predation.
Kelly, J. P. 2002. Options for the management of Common Ravens in heronries. ACR Tech. Rpt. 98-9-3. Audubon Canyon Ranch, P.O. Box 808, Marshall, CA 94940.