Baerwald, Erin; Patterson, Bill; and Barclay, Robert Origins and migratory patterns of bats killed by wind turbines in southern Alberta: evidence from stable isotopes ~ Abstract. Large numbers of migratory bats are killed every autumn at wind energy facilities in North America. While this may be troubling from a population perspective, these fatalities provide an opportunity to learn more about bat migration and the origins and summer distributions of migratory bats by using endogenous markers. Such markers include stable isotope values, which have been used to answer questions about ecological systems, such as trophic levels and food webs, and the origins and migratory routes of . . .