The role of male-male aggressive signals in reproductive isolation between two hybridizing warblers

Bird-song has been extensively studied for its role in pre-mating reproductive isolation between species. Sometimes song fails to effectively isolate a species and hybrids are produced, giving an opportunity to investigate the mechanisms of how song might act as a reproductive barrier. The ways in which two hybridizing species respond to and recognize each other’s songs can influence the dynamics of the hybrid zone, both via female mate choice and male-male competition. In many species the same song functions for both female mate choice and male-male competition. However, some species, such as the Parulidae Warblers, sing songs with specific functions, where one song is thought to function for female mate choice and the other for male-male competition. My main research goal was to determine how a song thought to function in the context of male-male competition might influence hybridization dynamics between two species. I used Blue-winged Warblers (Vermivora cyanoptera) and Golden-winged Warblers (Vermivora chrysoptera) as my model system because they are closely related species that hybridize frequently and produce fertile offspring, yet tend to mate assortatively and hold overlapping territories. They sing two different categories of song; Type-I song (thought to function for female mate choice) and Type-II song (specialized songs thought to function primarily in male-male territorial disputes). My results demonstrate that patterns of hybridization are associated with differences in both Type-II song structure and the ability to discriminate between conspecific and heterospecific Type-II songs, suggesting that Type-II song can facilitate a breakdown in reproductive isolation between BWWA and GWWA.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Natural Res & Env Sciences

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2020

Author dc:creator

• Tyndel, Stephen Albert

Contributors dc:contributor

• Ward, Michael P
• Sperry , Jinelle H
• Benson, Thomas J.

• Communication
• Hybridization
• Speciation

Statement dc:rights

• Copyright 2019 Stephen Tyndel

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/106426

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/106426