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

Authors

  • Dominique Fauteux Chaire industrielle CRSNG-UQAT-UQAM* en aménagement forestier durable and Centre d’étude de la forêt, Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, Québec J9X 5E4
  • Gilles Lupien Ministère du Développement durable, de l’Environnement, de la Faune et des Parcs, Direction régionale du Saguenay-Lac Saint-Jean, Jonquière, Québec G7X 8L6
  • François Fabianek Centre d’étude de la forêt, Faculté de foresterie, géographie et géomatique, Université Laval, Québec, Québec G1V 0A6
  • Jonathan Gagnon Chaire industrielle CRSNG-UQAT-UQAM* en aménagement forestier durable and Centre d’étude de la forêt, Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, Québec J9X 5E4
  • Marion Séguy Chaire industrielle CRSNG-UQAT-UQAM* en aménagement forestier durable and Centre d’étude de la forêt, Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, Québec J9X 5E4
  • Louis Imbeau Chaire industrielle CRSNG-UQAT-UQAM* en aménagement forestier durable and Centre d’étude de la forêt, Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, Québec J9X 5E4

DOI:

https://doi.org/10.22621/cfn.v128i1.1546

Keywords:

Lagomorpha, Rodentia, Soricomorpha, Carnivora, Chiroptera, shrews, moles, voles, lemmings, mice, bats, hares, weasels, lower jaw, skull, dentary, eastern Canada

Abstract

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.

Published

2014-03-23

Issue

Section

Articles