Divergence in vocalizations indicates cryptic speciation in Camptostoma tyrannulets

Author(s)

Lima, Rafael Dantas ; Vaz, Ruan Vieira

• Document type: Journal article
• Source: AUK; v. N/A, p. 17-pg., 2024-12-21.

Abstract

The tyrant flycatcher genus Camptostoma currently comprises 2 visually similar species: C. imberbe (Northern Beardless-Tyrannulet), ranging from the southern United States to Costa Rica, and C. obsoletum (Southern Beardless-Tyrannulet), found from Costa Rica to Uruguay. Vocal and genetic differences have suggested that C. obsoletum may include multiple species, but no analysis of acoustic trait variation has been conducted within the genus. We analyzed a geographically comprehensive sample of sound recordings to measure geographic variation in vocalizations across the genus, testing the hypothesis that C. obsoletum includes multiple species. We find that Camptostoma comprises 8 vocally distinct populations, 2 within C. imberbe and 6 within C. obsoletum. These populations exhibit diagnostic differences in multiple different vocalizations, including vocalization types that are typically species-specific in the Tyrannidae. Their range limits and contact zones largely correspond with known dispersal barriers, ecotones, and suture zones, with little evidence of gene flow between adjacent populations. Our results strongly suggest that Camptostoma comprises as many as 8 vocally distinct biological species, underscoring the underestimated diversity of species in birds with conservative plumage evolution. center dot The avian genus Camptostoma is currently classified into 2 widespread species, but fragmentary vocal and genetic evidence suggests it may include more.center dot Analysis of acoustic trait variation reveals 8 vocally distinct Camptostoma populations with abutting geographic ranges and limited gene flow.center dot Significant differences in vocalizations suggest that Camptostoma comprises as many as 8 biological species. El g & eacute;nero de atrapamoscas tiranos Camptostoma actualmente comprende dos especies visualmente similares: C. imberbe, que se encuentra desde el sur de los Estados Unidos hasta Costa Rica, y C. obsoletum, que se distribuye desde Costa Rica hasta Uruguay. Diferencias vocales y gen & eacute;ticas sugieren que C. obsoletum podr & iacute;a incluir m & uacute;ltiples especies, pero no se ha realizado un an & aacute;lisis de variaci & oacute;n de rasgos ac & uacute;sticos dentro del g & eacute;nero. Analizamos una muestra geogr & aacute;ficamente completa de grabaciones de sonido para medir la variaci & oacute;n geogr & aacute;fica en las vocalizaciones del g & eacute;nero, poniendo a prueba la hip & oacute;tesis de que C. obsoletum incluye m & uacute;ltiples especies. Encontramos que Camptostoma comprende 8 poblaciones vocalmente distintas, 2 dentro de C. imberbe y 6 dentro de C. obsoletum. Estas poblaciones presentan diferencias diagn & oacute;sticas en varias vocalizaciones, incluidos tipos de vocalizaci & oacute;n que son t & iacute;picamente espec & iacute;ficos de especies en la familia Tyrannidae. Sus l & iacute;mites de distribuci & oacute;n y las zonas de contacto correspondieron en gran medida con barreras de dispersi & oacute;n conocidas, ecotonos y zonas de sutura, con poca evidencia de flujo g & eacute;nico entre poblaciones adyacentes. Nuestros resultados sugieren fuertemente que Camptostoma comprende hasta 8 especies biol & oacute;gicas vocalmente distintas, subrayando la diversidad subestimada de especies en aves con una evoluci & oacute;n conservadora del plumaje. (AU)

• FAPESP's process: 21/10339-1 - Integrative taxonomy of two highly polytypic thamnophilids (Aves: Thamnophilidae)
• Grantee: Rafael Dantas Lima
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 23/11086-5 - Can common biogeographic patterns and processes explain the taxonomy of Cichlocolaptes and Heliobletus (Aves: Furnariidae), two genera endemic to the Atlantic Forest?
• Grantee: Ruan Vieira Vaz
• Support Opportunities: Scholarships in Brazil - Master