Quantifying Sexual Dimorphism in Tanagers through 3D Photogrammetry: Insights from Color Diversity and Pattern Complexity

Presenter

Vandrey J. Sisson

Campus

UMass Amherst

Sponsor

Duncan Irschick, Department of Biology, UMass Amherst

Schedule

Session 1, 10:30 AM - 11:15 AM [Schedule by Time][Poster Grid for Time/Location]

Location

Poster Board A57, Campus Center Auditorium, Row 3 (A41-A60) [Poster Location Map]

Abstract

The examination of color has played a crucial role in advancing our understanding of avian behavior and diversity. Behavioral ecologists have been aware of birds' ultraviolet (UV) vision since the 1970s, but it's only in the last few decades that studies on plumage color have integrated this knowledge into research endeavors. Our research project has focused on sexual dichromatism in a vibrant radiation of Neo-tropical songbirds known as tanagers. This phenomenon, characterized by phenotypic and behavioral differences between conspecific males and females, spans a wide spectrum within the tanager family. Studying sexual dichromatism offers valuable insights into the evolutionary processes shaping ecological diversity and helps us better understand the complex interplay of genetics, hormones, and social influences. However, defining a straightforward method to measure and quantify sexual dichromatism is relatively nuanced. The widespread use of color spectrophotometers, as well as a practical model of the avian visual system, has allowed researchers to quantify bird color for understanding sexual selection, visual communication, and most importantly, sexual dichromatism. While spectrophotometers are excellent for obtaining reflectance values of patches across the entire avian visual spectrum, the data are limited to discrete, patch-by-patch reflectance values. Novel techniques utilizing 3D photogrammetry can overcome this limitation and obtain full-body color data, providing a more comprehensive color analysis across the entire specimen. Here, we report full-body coloration data on a subset of the Thraupinae family (tanagers). Additionally, we quantify full-body sexual dichromatism through both a color diversity lens, as well as analyzing pattern complexity.

Keywords

ornithology, color, dichromatism, color patterns and complexity, sexual selection

Research Area

Animal Behaviour

SIMILAR ABSTRACTS (BY KEYWORD)