The male’s oversized jaws are crucial in its objective to secure a mate. It climbs trees, often climbing many meters, searching for a female. As it climbs and searches for females, it also seeks out other males in the vicinity. When two males meet, they fight. Males use their jaws in combat: they hook them under the opposite beetle’s wings, pull up and throw their opponent to the ground (from 20 meters above, as they are in great trees most of the time).Charles Darwin collected the species in Chile during the second voyage of HMS Beagle, and, despite the enlarged mandibles of the males, he noted that the jaws were “not so strong as to produce pain to finger”.
Chiasognathus grantii is one of the seven species belonging to the genus Chiasognathus. It belongs to the subfamilyLucaninae, the largest subfamily in the stag beetle family Lucanidae. C. grantii is also known locally as ciervo volante, cantaria, and cacho de cabra in Spanish and llico-llico in the Mapuche language.