In a pioneering study of signal design, Marler (Marler 1955 Nature 176, 6–8; Marler 1957 Behav. 11, 13–37) argued that the contrasting acoustic design of hawk (seet) and mobbing alarm calls of Europea
Bat fatalities at wind energy facilities in North America are predominantly comprised of migratory, tree-dependent species, but it is unclear why these bats are at higher risk. Factors influencing bat
