Bite force and jaw stress in the jaguar (Panthera onca) during predation of the peccaries (Artiodactyla: Tayassuidae) by fracture of its skulls

摘要

align="justify"> face="verdana" size="2">One of the most effective ways of the jaguar's predation (Panthera onca) is the application of bite force at the neurocranium of peccaries, one of its main natural preys, causing highly compressive stress that becomes fracture with its back a quick killing. In the present study were analyzed by the method of dry skull, 15 adult jaguar's skulls moreover completing craniometrical measures with reported data in the literature belonging to different subspecies or phenotypes of this species' distributional range, to obtain its maximum bite's force canines and carnassials moreover of the cutting efforts and maximum flexor moments along the jaw. The resolution of these variables in a hiperestaticity structure is achieved through the Moment Distribution Method by Cross. After correlated the maximum bite forces of the jaguar and its action in the cross section of the neurocranium of Pecari tajacu, Tayassu pecari and Catagonus wagneri by Cremona method to obtain the internal stress for before skull fracture. It was found that jaguar's maximum canine bite force is of 681.56 Newton and in the carnassials line is still 3 times most compressive. These forces are sufficiently high to cause fracture of a rigid structure as is the neurocranium's triangular section of the peccaries. Moreover the jaguar's robust canines resist the bending forces applied by struggling prey and a wider muzzle helps to stabilize grip and distribute bite forces more evenly during the killing bite.