Effects of weevil larvae on acorn use by blue jays

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• 作者：Mark D. Dixon ; W. Carter Johnson and Curtis S. Adkisson
• 关键词：Key words  ; Tri ; trophic interactions ; Oaks ; Tannins ; Blue jay ; Weevils
• 刊名：Oecologia
• 出版年：1997
• 出版时间：July 1997
• 年：1997
• 卷：111
• 期：2
• 页码：201-208
• 全文大小：146 KB
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Life Sciences
  Ecology
  Plant Sciences
  
• 出版者：Springer Berlin / Heidelberg
• ISSN：1432-1939

文摘

 Blue jays (Cyanocitta cristata L.) are important consumers and dispersers of the nuts of oaks and other fagaceous trees in eastern North America. Acorns compose much of the jay diet, especially during the autumn when jays may consume or cache a significant portion of an acorn crop. However, jays do not appear to possess physiological adaptations for countering the protein-binding properties of secondary compounds (tannins) found in acorns. We offered captive blue jays a mixture of infested 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 and then offered to individual jays in an outdoor aviary. Jays handled, opened, and consumed uninfested nuts significantly more often than infested nuts, and use of infested nuts did not increase during continued exposure to a high-tannin diet.