“…Similarly, the requirement for broad mechanical modulations in the production of wide frequency bandwidth necessarily limits cycle rates and thus realized trill rates. Trade-offs between trill rate and frequency bandwidth have since been described in greater detail for a wide range of songbird species, including swamp sparrows (Ballentine et al, 2004;Liu et al, 2008), dark-eyed juncos (Cardoso et al, 2007), Lincoln's sparrows (Sockman, 2009), yellow warblers (Beebee, 2004), black-throated blue warblers (Colbeck et al, 2010), banded wrens (Illes et al, 2006), and red-winged blackbirds (Cramer and Price, 2007). Similar trade-offs have also been described outside of songbirds, including in two seabirds, the brown skua and the great frigatebird (Juola and Searcy, 2011), in a rodent, the neotropical singing mouse (Pasch et al, 2011), and in bat echolocation calls (Schumm et al, 1991;but see Schmeider et al, 2010).…”