"No Trespassing"
Beata Ujvari, Research Fellow

The frill of the frillneck lizard (Chlamydosaurus kingii) functions as a predator deterrent, but is also used in male-male combats that often start by two males facing each other with fully erected frills. Thus, male frill size may be subjected to sexual selection. Indeed, we found that male frill size was significantly larger at a high-density site at Fogg Dam compared to a low-density site at Scotts Creek. The larger frill size in Fogg Dam males was most likely caused by increased frequency of male contests, resulting in an intensified selection of a trait strongly associated with male reproductive success.