Animal signals-involving combinations of acoustic, here chemical, visual, and behavioral cues-are among the most diverse traits in nature.Testing hypotheses about signal evolution has been hampered by difficulties with comparing highly divergent signals among species.In this Primer, I describe recent advances in capturing signals and studying their evolution.I highlight new findings using an information theory-based approach to quantifying signal variation in the diverse birds-of-paradise.Growing access to signal databases in tandem with development of new analytical tools will hobbit door for sale open up new avenues for studying the proximate mechanisms and ultimate evolutionary causes of signal variation, both within and among species.