Drivers of phenotypic divergence in a Mesoamerican highland bird

Abstract

Animals derive their coloration from a variety of pigments as well as non-pigmentary structural features. One of the most widespread types of pigments are carotenoids, which are used by all invertebrate taxa and most vertebrate orders to generate red, pink, orange and yellow coloration. Despite their widespread use by diverse animal groups, animals obligately obtain carotenoid pigments from diet. Carotenoid-based coloration is therefore modulated by evolutionary and ecological processes that affect the acquisition and deposition of these pigments into tegumentary structures. The Flame-colored Tanager (Piranga bidentata) is a highland songbird in the cardinal family (Cardinalidae) that is distributed from Mexican sierras through Central America up to western Panama. While female plumage throughout its entire range is predominantly yellow, males exhibit a noticeable split in ventral plumage color, which is bright orange on the West slope and the Tres Marias Islands and blood red in Eastern Mexico and Central America. We used Multiple Regression on Matrices (MRM) to evaluate the relative contributions of geographic distance, climate and genetic distance on color divergence and body differences between geographically disjunct populations. We found that differentiation in carotenoid plumage coloration was mainly explained by rainfall differences between disjunct populations, whereas body size differences was best explained by variation in the annual mean temperature and temperature of coldest quarter. These results indicate that climate is a strong driver of phenotypic divergence in Piranga bidentata.

Recent genetic, phenetic and ecological divergence across the Mesoamerican highlands: a study case withDiglossa baritula(Aves: Thraupidae)

“…If we assume that wing length is a good indicator of body size ( Ashton, 2002 ), we provide the first evidence for sexual dimorphism in body size in D. baritula . This pattern of differences between sexes in wing chord have been reported in other birds ( Robles-Bello et al, 2022 ; Thom et al, 2008 ; Sun et al, 2017 ).…”

Isolation by resistance explains genetic diversity in theArremonbrushfinches of northern Mesoamerica

“…For example, novel genomic reduced‐representation methods (e.g., RAD‐seq, GBS) have allowed the use of thousands of single nucleotide polymorphisms (SNPs) to address important topics in landscape genomics (hereafter LG) (McKinney et al, 2017; Puritz et al, 2014). Such applications include evaluating genetic isolation hypotheses or carrying out genome scans for loci under selection (Balkenhol et al, 2017; Robles‐Bello et al, 2022; Termignoni‐García et al, 2017). At the same time, the availability of high‐resolution spatial data has made it possible to generate isolation hypotheses that reflect the neutral genomic structure and variation of natural populations at different biologically relevant spatial scales (Balkenhol et al, 2016; Balkenhol & Fortin, 2016).…”

“…Such applications include evaluating genetic isolation hypotheses or carrying out genome scans for loci under selection (Balkenhol et al, 2017;Robles-Bello et al, 2022;Termignoni-García et al, 2017).…”