EFFECTS OF WEEVIL LARVAE AN ACORN USE BY BLUE JAYS

Blue jays (Cyanocitta cristata L.) are important consumers and dispers ers of the nuts of oaks and other fagaceous trees in eastern North Ame rica. Acorns compose much of the jay diet, especially during the autum n when jays may consume or cache a significant portion of an acorn cro p. However, jays do not appear to possess physiological adaptations fo r countering the protein-binding properties of secondary compounds (ta nnins) found in acorns. We offered captive blue jays a mixture of infe sted and uninfested pin oak (Quercus palustris Muenchh.) acorns to see if the birds would selectively consume nuts containing weevil larvae (Coleoptera: Curculionidae) as a protein supplement to a high-tannin, all-acorn diet. Acorns were X-rayed to determine infestation status an d then offered to individual jays in an outdoor aviary. Jays handled, opened, and consumed uninfested nuts significantly more often than inf ested nuts, and use of infested nuts did not increase during continued exposure to a high-tannin diet.