Male songbirds are known for their conspicuous broadcast songs. In most songbird species, broadcast songs are produced at high amplitudes such that their active space (the distance from a sound source over which a signal is detectable) extends well beyond territorial boundaries (Brenowitz 1982; Wiley & Richards 1982; Dabelsteen et al. 1993; Holland et al. 1998; Naguib & Wiley 2001). In addition...

or speculative to be considered a science of sincere importance. This is because in Metaphysics, there is no set of superior or empirical observations, nor, is there a valid set of logical arguments which could definitively prove metaphysical axioms to be either true or false. Therefore, a metaphysical truth usually implies a belief about the perceived environment or world. Nevertheless, what m...

USC Eye Institute, University of Southern California, Los Angeles, California, United States Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, Los Angeles, California, United States Keck School of Medicine, University of Southern California, Los Angeles, California, United States Institute for Biomedical Therapeutics, University of Southern Cal...