Résumé - CAFD


An illustrated key to the mandibles of small mammals of eastern Canada.

Dominique Fauteux, Gilles Lupien, François Fabianek, Jonathan Gagnon, Marion Séguy, Louis Imbeau.

Skulls are often used to identify small mammals, and most identification keys to small mammals have been developed on the
assumption that whole skulls will be available. however, the skulls of small mammals are seldom found intact in predator
pellets or nests, and the bones of several individuals are often scattered and mixed, making counting impossible without the
use of a specific cranial part. In addition, only a few keys include all the species found in the eastern provinces of Canada.

Mandibles readily resist degradation by the gastric acids of both avian and mammalian predators and are often found intact
in food caches of mustelids and in bat hibernacula. We therefore designed an illustrated dichotomous key to small mammals
(mean mass <5 kg) of eastern Canada based on diagnostic mandible characters (including the teeth and one dentary bone).
We identified and confirmed diagnostic characters to distinguish 55 species from the orders lagomorpha, rodentia, Soricomorpha,
Carnivora, and Chiroptera. these diagnostic characters are based on a review of the literature and were confirmed
by measurements performed on both museum and trapped specimens. In order to facilitate identification, photographic illustrations
are provided for each couplet of the key.

the ability to identify small mammals using their mandibles will reduce the number of skull components needed and has proven
to be a useful tool in the study of the diet of predators. this key may also be helpful in identifying bats in the genera Myotis,
Perimyotis, and Eptesicus, which are presently affected by the spread of white-nose syndrome (caused by Pseudogymnoascus
destructans) throughout the eastern part of Canada.