Experimentally testing mate preference in an avian system with unidirectional bill color introgression. Issue 2 (21st February 2023)

• Record Type: Journal Article
• Authors: McDiarmid, Callum S.; Finch, Fiona; Peso, Marianne; van Rooij, Erica; Hooper, Daniel M.; Rowe, Melissah; Griffith, Simon C.
• Is Part Of: Ecology and evolution. Volume 13:Issue 2(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2023-02-21
• Subjects: avian -- bill color -- hybrid zone -- introgression -- mate preference; Ecology -- Periodicals; Evolution -- Periodicals; 577.05
• DOI: 10.1002/ece3.9812
• Languages: English
• ISSNs: 2045-7758

Abstract

Abstract: Mating behavior can play a key role in speciation by inhibiting or facilitating gene flow between closely related taxa. Hybrid zones facilitate a direct examination of mating behavior and the traits involved in establishing species barriers. The long‐tailed finch ( Poephila acuticauda ) has two hybridizing subspecies that differ in bill color (red and yellow), and the yellow bill phenotype appears to have introgressed ~350 km eastward following secondary contact. To examine the role of mate choice on bill color introgression, we performed behavioral assays using natural and manipulated bill colors. We found an assortative female mating preference for males of their own subspecies when bill color was not manipulated. However, we did not find this assortative preference in trials based on artificially manipulated bill color. This could suggest that assortative preference is not fixed entirely on bill color and instead may be based on a different trait (e.g., song) or a combination of traits, or alternatively may be due to lower statistical power alongside the bill manipulations being unconvincing to the female choosers. Intriguingly, we find a bias in the inheritance of bill color in captive bred F1 hybrid females. Previous modeling suggests that assortative mate preference and this kind of partial dominance in the underlying genes may together contribute to introgression, making the genetic architecture of bill color in this system a priority for future research. Abstract : We investigate whether mate choice might play a role in the unidirectional introgression of yellow bill color between subspecies of the long‐tailed finch. Females demonstrate an assortative mate preference for unmanipulated males of their own subspecies. However, the evidence that females base this assortative preference on bill color is equivocal.