Elections
Conference
Members
Donate

Identification of black and brown bear skulls by tooth morphology

Identification of black and brown bear skulls by tooth morphology

Skulls of American black bears (ABB, Ursus americanus) and brown bears (BRB, U. arctos) can be very similar, and their sizes overlap. Methods to distinguish the skulls of these two species were developed but none proved reliable and easily applicable in the field. This study examined the presence versus absence of the accessory cusps in the skulls of 71 BRB and 41 ABB. The following results were obtained from skulls with ≥1 evaluable m1: accessory cusp was detected in 98.1% of BRB, and the absence of accessory cusp was confirmed in 100% of ABB. We recommend accompanying this method with the gross assessment of the ratio of the length of the facial region and the braincase of the skull. The facial region of ABB is usually shorter than the braincase; whereas in BRB, the braincase is longer than the facial region or they are equal in size.