Felis catus preying on a Megasorex gigas, an endemic and threatened shrew from México

Abstract

The proliferation of cats (Felis catus) has dramatically increased, leading to a worldwide serious conservation issue.  In tropical and megadiverse regions, their impact on wildlife has still been poorly documented.  The objective of this note was to report a shrew potentially hunted by a cat in Colima, México.  On January 30, 2022, we took a recently hunted shrew off a cat at the Centro Universitario de Gestión Ambiental (CEUGEA).  We initially detected the predator about 25 m away playing with a prey.  We approached the cat and scared it to examine the shrew, which was fresh and had an open wound on one of its flanks.  After carefully examining the specimen, we identified it as the Mexican shrew Megasorex gigas based on external and cranial characteristics.  Megasorex is a monotypic genus endemic to western México.  It is considered Threatened by the Mexican government and has been determined rare.  Cats have been sighted hunting the fauna of CEUGEA, whereas the report of cats hunting shrews has been historically typical in temperate zone countries.  In tropical regions, anecdotal records of cats leaving dead shrews in homes are not uncommon.  However, there has not been an accurate and formal record of these events that would allow documenting the possible impact of such predators on shrews.  We hope that this note might serve to begin a systematization of cat predation records on shrews for enhancing the comprehension of the effect of invasive exotic species on native fauna in megadiverse countries.