South Hills Crossbill Attacking Pine Cone (IMAGE) University of Chicago Press Journals Caption A male South Hills crossbill using its crossed mandibles to bite between lodgepole pine cone scales to access seeds. The decurved mandibles enable crossbills to exert strong biting forces at the tip of their bill. Credit photograph by Craig Benkman Usage Restrictions credit must be given to Craig Benkman License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.