Periodic Reporting for period 1 - EvoColorIsla (Evolution of Female Ornamentation: a comparative and experimental approach using island birds)
Reporting period: 2022-04-04 to 2024-04-03
What drives the evolution of female ornamentation? Explaining the evolution of signals found in nature has been a persistent challenge for biologists, but studies have focused mostly on male ornaments, neglecting the question of why and how these traits evolve in females. Oceanic islands around the world provide a “natural laboratory” setting to test evolutionary processes due to their simplified ecosystems, and high levels of endemic species with variation in some specific traits. In particular, island species experience changes in sociality, competition, and predation, all of which are known to influence ornamental traits.
EVOCOLORISLA aimed to investigate whether and how female colours change following island colonization and identify the evolutionary pressures driving these shifts, using both macro and microecological-evolutionary approaches. Specifically, we 1) investigated the mechanisms associated with female and male ornamentation following island colonisation, 2) tested the extent to which predation risk predicts ornamentation, and 3) tested the relationship between variation in ornamentation and social competition.
EVOCOLORISLA aimed to investigate whether and how female colours change following island colonization and identify the evolutionary pressures driving these shifts, using both macro and microecological-evolutionary approaches. Specifically, we 1) investigated the mechanisms associated with female and male ornamentation following island colonisation, 2) tested the extent to which predation risk predicts ornamentation, and 3) tested the relationship between variation in ornamentation and social competition.
To achieve objectives 1, this project used data from museums and literature for endemic island species and their closest relatives from mainland worldwide to examine the female and male plumage colours in island and mainland species and identify key evolutionary drivers, including sexual selection, social competition, predation risk, sociality, species recognition, and ecological factors. Our analysis of plumage coloration uses psychological models of avian vision and a comprehensive dataset collected at Naturalis museum (Leiden, Netherlands), and compiled from international collaborations, which jointly represents ~ 8706 species, covering approximately 79% of bird diversity. To assess the role of putative drivers, we gathered information on relevant geographical, socio and ecological data from existing databases within our collaborators and relevant literature. A full description of the methods and results, including the associated code, is being prepared for publication and will also be presented at a conference in May, 2025.
To achieve objectives 2 and 3, EVOCOLORISLA used field-based data to test the hypothesis that colour changes on islands are linked to changes in predation and social competition. To do this, we built and painted 3D printed model from 3D photogrammetry of museum specimens from Natural History Museum of the University of Porto. Experiments involved 14 species including island endemics and their closest mainland relatives. The study took place in the Atlantic Islands of Macaronesia, including Madeira, the Azores, and the Canary Islands, as well as mainland Portugal. Our analysis is still ongoing, and we expect that these results will be published and made publicly available later this year. Part of this work has been presented at the Ethology conference, Portugal, 2024.
From the current project, the fellow also had the chance to:
- Participate in outreach activities such as Escola Ciência Viva" programme for pre-schoolers (“Investigador Falador”, Portugal), to talk about “The Colors of Island Birds”.
- Create a website and setup social media outlets to disseminate the project and related projects: The Island Bird Project Website - www.islandbirdproject.com - provides information on the team, funded projects, news, and research opportunities. The Bluesky account @islandbirdproject.bsky.social shares news about the team and projects.
To achieve objectives 2 and 3, EVOCOLORISLA used field-based data to test the hypothesis that colour changes on islands are linked to changes in predation and social competition. To do this, we built and painted 3D printed model from 3D photogrammetry of museum specimens from Natural History Museum of the University of Porto. Experiments involved 14 species including island endemics and their closest mainland relatives. The study took place in the Atlantic Islands of Macaronesia, including Madeira, the Azores, and the Canary Islands, as well as mainland Portugal. Our analysis is still ongoing, and we expect that these results will be published and made publicly available later this year. Part of this work has been presented at the Ethology conference, Portugal, 2024.
From the current project, the fellow also had the chance to:
- Participate in outreach activities such as Escola Ciência Viva" programme for pre-schoolers (“Investigador Falador”, Portugal), to talk about “The Colors of Island Birds”.
- Create a website and setup social media outlets to disseminate the project and related projects: The Island Bird Project Website - www.islandbirdproject.com - provides information on the team, funded projects, news, and research opportunities. The Bluesky account @islandbirdproject.bsky.social shares news about the team and projects.
By integrating comparative, field-based and experimental work, EVOCOLORISLA aims to provide the most comprehensive understanding to date of female and male colour evolution on islands. Furthermore, this project constitutes the first step that will shed light on our understanding of the factors driving the diversity of phenotypic traits on islands, while redressing the sex bias in research by focusing on both female and male signal evolution.