Increased diet breadth of little brown bats (Myotis lucifugus) at their northern range limit: a multi-method approach

• Main Authors: Shively, Rachel, Barboza, Perry, Doak, Patricia, Jung, Thomas
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: NRC Research Press (a division of Canadian Science Publishing) 2017
• Subjects: Arctic; Yukon; Guano; Subarctic; Alaska
• Online Access: http://hdl.handle.net/1807/81164; http://www.nrcresearchpress.com/doi/abs/10.1139/cjz-2017-0017

The distribution of small mammals is constrained by extreme environmental demands and variable food supplies that are commonly incurred at northern latitudes. Little brown bats (Myotis lucifugus Le Conte, 1831) are at the northwestern limits of their range in Alaska, where environmental demands are higher and prey availability is more seasonal than elsewhere in their range. We hypothesized that the little brown bat in interior Alaska has adjusted to these constraints by broadening its foraging niche, relative to that of southern conspecifics. We analyzed arthropod fragments (microhistology) in guano to describe prey composition to Order. We compared the efficacy of evaluating diet by microhistology with DNA analysis and stable isotope analysis on guano and hair. Bats consumed aerial prey such as Lepidoptera (moths) and Diptera (flies and mosquitoes) as well as terrestrial arthropods including Araneae (spiders). Shifts in the proportion of aerial prey in the diet were closely linked to ordinal day. Values for â 15N in hair indicated that bats were generalists in interior Alaska, coastal Alaska and Yukon but significant outliers indicated that some individuals have distinct diets. The little brown batâ s flexibility in feeding strategies likely allows this species to sustain populations in arctic and subarctic regions. The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author.