Abberant Coloration in a Little Brown Bat (Myotis lucifugus) from the Yukon

Abstract

Variation in the pigmentation of mammals is widespread. Color aberrations in bats, however, are rarely reported in the literature, despite many thousands of bats being observed annually (Trapido and Crowe 1942; Quay 1970; Walley 1971; Smith 1982). On rare occasions, bats from the genus Myotis have been observed that are melanistic (excessive pigmentation: Buchanan 1985), silvered (white-tipped hair: Munzer and Kurta 2008), leucistic (reduced or absent integumentary pigmentation with pigmented eyes: Trapido and Crowe 1942; Metzger 1956; Rogers 1965; Walley 1971), or albinistic (reduced or absent integumentary pigmentation with unpigmented eyes: Walley 1974; Smith 1982; Harada and others 1991; Brigham and James 1993; Brack and others 2005). Here we report an observation of leucism in a Little Brown Bat (Myotis lucifugus) from northwestern Canada. During a study of Little Brown Bat maternity colonies in and near Watson Lake, Yukon, Canada (60.1°N, 128.70W), we used mist-nets to capture Little Brown Bats as they emerged from their diurnal roosts in buildings. On 7 June 2006, we captured an adult female that exhibited abberant coloration. Both wing tips were unpigmented, whereas the rest of the coloration (such as pelage, uropatagium, face, feet, ears, and eyes) was typical for the species (Fig. 1). Extent of the unpigmented portion of the flight membranes was asymmetrical, with the tip of the left wing having about twice the amount of unpigmented area as the right. Other than its unusual coloration, the individual appeared and behaved like others captured at the study area. The bat was pregnant, as determined by gentle palpation of the abdomen. It weighed 8.4 g, had a forearm length of 38.0 mm, and had an ear length of 11.3 mm. The bat