“…125 season with >10 visits (i.e., at least fall and spring, or two falls), (3) tower height was provided, and (4) total number of birds killed was provided. To calculate annual mortality, we assumed that fall surveys constituted 75% of a year and that spring surveys constituted 25% (Crawford and Engstrom 2001). For each study or set of studies at the same location, we recorded mean annual mortality (total kill divided by number of years), the number of years of the study, tower height (m), and the presence and number of sets of guy wires and the presence and type of lighting if provided.…”