title: Aposematism increases acoustic diversification and speciation in poison frogs.
abstract: Multimodal signals facilitate communication with conspecifics during courtship, but they can also alert eavesdropper predators. Hence, signallers face two pressures: enticing partners to mate and avoiding detection by enemies. Undefended organisms with limited escape abilities are expected to minimize predator recognition over mate attraction by limiting or modifying their signalling. Alternatively, organisms with anti-predator mechanisms such as aposematism (i.e. unprofitability signalled by warning cues) might elaborate mating signals as a consequence of reduced predation. We hypothesize that calls diversified in association with aposematism. To test this, we assembled a large acoustic signal database for a diurnal lineage of aposematic and cryptic/non-defended taxa, the poison frogs. First, we showed that aposematic and non-aposematic species share similar extinction rates, and aposematic lineages diversify more and rarely revert to the non-aposematic phenotype. We then characterized mating calls based on morphological (spectral), behavioural/physiological (temporal) and environmental traits. Of these, only spectral and temporal features were associated with aposematism. We propose that with the evolution of anti-predator defences, reduced predation facilitated the diversification of vocal signals, which then became elaborated or showy via sexual selection.
authors.affiliation: Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4 National Evolutionary Synthesis Center, Suite A200, 2024 West Main St., Durham, NC 27705, USA jcsantos@biodiversity.ubc.ca infraguttatus@gmail.com.
authors.forename: Juan C
authors.initials: JC
authors.lastname: Santos
authors.affiliation: Department of Biological Sciences, Mississippi State University, Starkville, MS 39762, USA.
authors.forename: Margarita
authors.initials: M
authors.lastname: Baquero
authors.affiliation: Instituto de Biodiversidad Tropical, Uvita, Costa Rica.
authors.forename: César
authors.initials: C
authors.lastname: Barrio-Amorós
authors.affiliation: Centro Jambatu de Investigación y Conservación de Anfibios, Fundación Otonga, Geovanni Farina 566 y Baltra, San Rafael, Quito, Ecuador.
authors.forename: Luis A
authors.initials: LA
authors.lastname: Coloma
authors.affiliation: Instituto Nacional de Pesquisas da Amazônia - INPA, Manaus, Amazonas, Brazil.
authors.forename: Luciana K
authors.initials: LK
authors.lastname: Erdtmann
authors.affiliation: Instituto Nacional de Pesquisas da Amazônia - INPA, Manaus, Amazonas, Brazil.
authors.forename: Albertina P
authors.initials: AP
authors.lastname: Lima
authors.affiliation: Department of Integrative Biology and Texas Natural History Collections, University of Texas, 1 University Station C0990, Austin, TX 78712, USA.
authors.forename: David C
authors.initials: DC
authors.lastname: Cannatella
mesh_terms: D000162:Acoustics; D000819:Animal Communication; D000818:Animals; D001001:Anura / Q000145:classification / Q000502:physiology*; D005075:Biological Evolution; D008297:Male; D052586:Mating Preference, Animal; D008954:Models, Biological; D008969:Molecular Sequence Data; D010802:Phylogeny; D013045:Species Specificity
keywords: aposematism; mating signals; natural selection; sexual selection