Plumage Coloration Research Articles

First report on the diversity of domestic pigeons (Columba livia) using plumage coloration and patterning in Saravena, Arauca, Colombia

The domestic pigeon (Columba livia Gmelin, 1789), native to Africa and Eurasia, is extensively found across Europe, Western Asia, Africa, and the Americas. The pigeon (Columba livia) was domesticated several centuries ago and holds a privileged place as a symbol of peace, love, fidelity, and ornamentation in parks. In recent decades, an increase in the populations of these pigeons has been detected. The Spanish brought Columba livia to Colombia in the 15th century. The objective of this study was to evaluate the genetic diversity of the domestic pigeon using loci related to plumage coloration and patterning in Saravena. Random sampling was conducted in six colonies between March and April 2024. Through urban visits, direct observation, and photographic records, a phenotypic classification of each of the 580 pigeons from the different flocks studied was carried out. Autosomal markers associated with coloration and plumage were analysed: Grizzle, Spread, Checker, and the sex-linked locus Ash-Red. Genetic profiles were calculated using indices: allele frequency, genetic diversity, and population structure, estimated with the PopGene 1.31 program. Diversity was assessed using the FSTAT program. The dendrogram was constructed with the MEGA X program. The marker with the highest allele frequency was Grizzle (P=0.1834), while the Spread marker had the lowest values (P=0.0300). The highest HT value was 0.3002 for the Grizzle marker, GST showed figures of 0.0360, and gene flow was 20.6; the FIS and FIT statistics reported values of 0.2779 and 0.2848, and FIT was 0.0091. Moderate genetic diversity, a deficit of heterozygotes, and an excess of homozygotes were observed, along with low interpopulation genetic differentiation and high gene flow between subpopulations. Low genetic distance values were also found between the studied subpopulations. The populations are closely related genetically, which may be due to their geographical proximity, which has favoured genetic exchange.

A molecular mechanism for bright color variation in parrots.

Parrots produce stunning plumage colors through unique pigments called psittacofulvins. However, the mechanism underlying their ability to generate a spectrum of vibrant yellows, reds, and greens remains enigmatic. We uncover a unifying chemical basis for a wide range of parrot plumage colors, which result from the selective deposition of red aldehyde- and yellow carboxyl-containing psittacofulvin molecules in developing feathers. Through genetic mapping, biochemical assays, and single-cell genomics, we identified a critical player in this process, the aldehyde dehydrogenase ALDH3A2, which oxidizes aldehyde psittacofulvins into carboxyl forms in late-differentiating keratinocytes during feather development. The simplicity of the underlying molecular mechanism, in which a single enzyme influences the balance of red and yellow pigments, offers an explanation for the exceptional evolutionary lability of parrot coloration.

Joint Genomic and Transcriptomic Analysis Reveals Candidate Genes Associated with Plumage Color Traits in Matahu Ducks

Plumage color is a key trait for identifying waterfowl breeds with significant economic importance. A white-feathered group has recently emerged within the native Matahu duck population, presenting an opportunity for breeding new lines. However, the genetic basis for this plumage variation is still unknown, necessitating further research. This study aims to identify the genetic mechanisms underlying the emergence of white-feathered individuals in the Matahu duck population through combined genome and transcriptome analysis, providing insights for selective breeding and the development of new white-feathered lines. In this study, a total of 1344 selected genes and 1406 significantly differentially expressed genes were identified through selection signal analysis and transcriptomic analysis, respectively. The functional enrichment of these genes revealed several key signaling pathways, including those related to cGMP-PKG, cAMP, PI3K-Akt, and MAPK. Furthermore, important candidate genes involved in melanin biosynthesis, such as MITF, MC1R, TYR, TYRP1, and ABCB6, were identified. Notably, 107 genes were detected by both methods, and, among these, DGKI, GPRC5B, HMX1, STS, ADGRA1, PRKAR2B, and HOXB9 are suggested to play a role in melanin formation and potentially influence plumage traits. Through the integrative approach combining genomic selection signals and transcriptomic analyses, we identified several candidate genes directly associated with plumage color, including MITF, TYR, TYRP1, and MC1R, along with multiple signaling pathways linked to melanin formation. We hypothesize that the expression of DGKI, GPRC5B, HMX1, STS, ADGRA1, PRKAR2B, and HOXB9, detected by both methods, may be closely related to the regulation of plumage color traits. These findings provide a foundational basis for further research aimed at elucidating the genetic mechanisms governing plumage color variation in ducks.

PSVII-5 Heat shock protein 70 gene expression and association with morphometric and heat tolerance traits in three plumage colors of Noiler chicken exposed to acute heat stress

Abstract Heat stress is one of the most difficult climatic conditions chickens faces and is a direct result of climate change. It is important to research poultry thermotolerance because it may help find genetic lines resistant to heat stress. This study investigated the influence of plumage colors on heat shock protein 70 gene expression in Noiler chickens exposed to acute heat stress. Noiler is a dual-purpose breed developed for smallholder poultry production in Nigeria. A total of 150 birds of three plumage colors (black, brown and white) of mixed sexes were used for the experiment. The birds were raised in deep litter house separated into six groups of 25 birds each and fed with commercial broiler diets from 0-8 wk and broiler finisher diets from 8 to 12 wk old. The birds were shared into treatments in 3 x 2 x 2 factorial arrangements with 3 plumage colors (black, brown, white), two temperature regimens (Control/thermoneutral, Heat stress) and sex of birds (male, female). The heat stressed birds were exposed to 41oC for 8 h from 0600 h to 1400 h for 7 d while control group maintained a thermoneutral temperature range of 30 oC to 32 oC for the same period. At 13 wk old, two birds were selected per treatment, slaughtered and the spleen removed and stored in RNA later for heat shock protein (HSP) 70 gene expression. Data collected were analyzed with Microsoft excel code for fold expression of HSP70 gene while GLM procedure in SAS was used to determine difference in expression of gene. The relative expression of HSP70 brown plumage was greater, upregulated compared with black and white. White plumage birds in control/thermoneutral group were significantly greater in HSP70 expression than other plumage colors and heat stressed birds. Association of HSP70 delta threshold cycle (DCT) values with morphometric and heat tolerance traits were investigated (Figure 1). High negative correlations emerged between HSP70DCT expression and body weight (-0.65), body temperature (-0.73) with moderate positive correlation for rectal temperature (0.55) in black birds (Table 1). HSP70 DCT positively correlated with body weight (0.70), breast/leg circumferences but negatively with wing length, suggesting reduced surface area during heat stress and a supportive role in maintaining protein integrity (Figure 2). For white Noiler birds, HSP70DCT associated negatively with body weight (-0.94) and positively with rectal temperature during heat stress (Table 2). Thermoneutral birds were positively correlated with heat tolerance traits except temperature while heat stressed birds showed low positive correlation with respiratory and pulse rates and very low positive relationship with body and rectal temperatures (Table 4). Sex-based differences emerged, with potential compromise between HSP70-mediated growth/composition in males versus muscle maintenance in females, although leg length/circumference showed shared developmental regulation (Figure 3, Table 3). These findings highlight HSP70’s versatile roles in systemic heat tolerance mechanisms influenced by plumage color, temperature regime and sex.

A novel codominant plumage color pattern of white breast patches in WugangTong geese was controlled by EDNRB2

Two basic plumage color patterns are observed in adult geese: solid grey (G) or colorless white (W). However, a Chinese indigenous breed, the Wugangtong goose (WGT), continues to be subject to selective breeding efforts as it displays segregation of plumage colors, including G, W, and a novel color pattern designated Wb (G with white breast circles). The underlying genetic mechanisms responsible for the Wb phenotype are yet to be determined. The current study employed the population differentiation index (FST) to analyze 90 geese exhibiting diverse plumage colors, identifying the fifth intron of EDNRB2 as a particularly noteworthy region with the highest FST values. Sanger sequencing of the region surrounding the EDNRB2 gene identified a 14-bp insertion within exon 3 as the causal mutation. The heterozygosity of this 14-bp insertion and wild-type alleles was completely associated with the Wb phenotype, thereby substantiating the codominant nature of the G and W phenotypes. An inter-species corroborated this finding cross between the graylag (no 14-bp insertion) and the swan goose (homozygous for the 14-bp insertion) breeds, as hybrids from this cross exhibited the Wb phenotype. Transcriptomes from white breast patches and gray dorsal skins of 4 Wb geese were compared. A significant downregulation of genes involved in melanin synthesis and melanocyte development was observed, including EDRNB2 and MLANA. The downregulation of MLANA indicated that the mutated EDNRB2 resulted in melanocyte loss in specific body regions, as MLANA is a marker gene for melanocytes. The findings were corroborated by melanin staining using the Mansson-Fontana method, which revealed no melanin particles deposited in the white breast patches. In summary, the gray plumage color was codominant to the white color in WGT geese, and plumage color variations were controlled by EDNRB2. The findings of our study offer valuable and practical guidance for the purification of plumage colors among WGT, whether through traditional phenotype selection or molecular breeding methods.

Characterization of the Coding Sequence of the MC1R (Melanocortin 1 Receptor) Gene of Ayam Cemani Black Chickens.

Plumage color is one of the most important traits characterizing chicken breeds. Black-boned chickens constitute a specific group of breeds with a unique phenotype. One of the representatives is the Indonesian Ayam Cemani. The extraordinary black phenotype results from a specific chromosomal rearrangement. We used complete CDS of crucial color-related gene MC1R, which plays a key role in melanin distribution but has not been previously studied in Ayam Cemani. It turned out that Ayam Cemani individuals possess a newly found non-synonymous mutation G355A resulting in amino acid substitution D119N. Together with the presence of G274A (E92K), the new missense variant enabled us to distinguish a new extended black allele at the E locus. All of the investigated birds were heterozygous in terms of the new mutation. Previous studies and our own results indicate a high level of genetic variation within the MC1R gene within and between chicken breeds. Besides the key mutations that make it possible to distinguish particular major alleles, there are also numerous substitutions that give haplotypes more characteristics for individual breeds.

A selection breeding pattern for sexually dimorphic breast plumage color in Guangxi Yao chickens

The breast plumage color of Guangxi Yao chickens shows obvious sexual dimorphism, with roosters showing black and black with red, and hens displaying partridge and red. Black plumage in roosters is considered a sign of quality, necessitating the purification of plumage color. Here, we developed an effective method based on genetic variations within MC1R and plumage characteristics. We clarified the distribution of 5 single nucleotide polymorphisms (SNP) and 3 haplotypes (H1, H2, and H3) of MC1R gene, and revealed potential associations between haplotype H1 and black breast plumage in the F2 resource population derived from a backcross between Guangxi Yao and Yellow chickens. Subsequently, using H1/H1 diplotype roosters and hens to construct families (n = 1,244) notably increased the proportion of offspring with black plumage. Further analysis suggested that red plumage in hens may be the putative phenotype of black plumage in roosters, driven by haplotype H1 of the MC1R gene, as verified by genotype and phenotype analysis. As expected, we found that almost all male offspring of hens with red breast plumage showed black plumage. In short, we established a selection pattern based on the combination of black-plumage roosters and red-plumage hens can significantly purify the sexually dimorphic plumage color and improve the efficiency of breeding programs in Guangxi Yao chickens. Our findings provide a novel technical framework to accelerate the breeding process for plumage trait in poultry.

Size differences among canaries, goldfinches and allies may explain correlated evolution of song and colour.

Sexual signals such as colour ornamentation and birdsong evolve independently of each other in some clades, and in others they evolve positively or negatively correlated. We rarely know why correlated evolution does or does not occur. Here, we show positively correlated evolution between plumage colour and song motor performance among canaries, goldfinches and allies, associated with species differences in body size. When controlling for body size, the pattern of correlated evolution between song performance and colour disappeared. Syllable diversity was not as strongly associated with size, and did not evolve in a correlated manner with colour. We argue that correlated evolution between song and colour was mediated by large size limiting song motor performance, likely due to constraints on the speed of moving heavier bills, and by larger species having less saturated plumage colour, possibly due to life-history traits of larger birds (e.g. longevity, stable pairs) contributing to weaker sexual selection. Results are consistent with the hypothesis that correlated evolution between sexual signals is influenced by how, in a clade, selective pressures and constraints affecting each type of signal happen to be co-distributed across species. Such contingency helps explain the diversity in clade-specific patterns of correlated evolution between sexual signals.

Elevated testosterone levels during moult have contrasting effects on structural and carotenoid‐based plumage colours in Eurasian Blue Tits

Elevated testosterone levels during moult have contrasting effects on structural and carotenoid‐based plumage colours in Eurasian Blue Tits

Multiple plumage color signals associated with courtship displays may represent body quality in male golden pheasants (Chrysolophus pictus)

Many animals display numerous colors that can range from red, green, blue, and orange to ultraviolet, whereas others are dull or have a uniform coloration. The reason for this variation in coloration remains unknown. It has been hypothesized that different colors represent multiple signals that either reflect different components, redundant information, or simply no longer provide reliable information regarding body quality. Here, we analyzed the highly diverse coloration of male golden pheasants ( Chrysolophus pictus) using an avian visual model from the avian visual system and related the different components of coloration to several phenotypic traits of body quality. We found that different components of plumage color correlated with the length of the body, tail, spur, and beak, suggesting that the multiple colors in male golden pheasants signal different components of body quality. In particular, tail length was correlated with many aspects of coloration, especially the green and orange colors of neck plumage, which are particularly important because male golden pheasants spread their neck plumage and show it to females during their courtship display. Therefore, these findings reveal that the plumage colors of male golden pheasants encode multiple signals that reflect their body condition during courtship displays.

Genome-wide association study reveals 2 copy number variations associated with the variation of plumage color in the white duck hybrid population

Plumage color is an intuitive external poultry characteristic with rich manifestations and complex genetic mechanisms. In our previous study, we observed that there were more dark variations in plumage color in the F2 population derived from the hybridization of 2 white duck varieties. Therefore, based on the statistics of plumage color of 308 F2 populations, we further used the resequencing data of these individuals to detect copy number variations (CNVs) in the whole genome and conducted genome-wide association studies (GWAS) to determine the genetic basis related to plumage color traits. The CNV detection revealed 9,337 CNVs, with an average length of 15,950 bp and a total length of 142.02 MB, accounting for approximately 12.91% of the reference genome. The CNV distribution on the chromosomes was relatively uniform, and the number of CNVs on each chromosome positively correlated with the length of the chromosome. In the pure black plumage group, 2,101 CNVs were only identified, and 1,714 were specifically identified in the pure white plumage group. Ten CNVs were randomly selected for validation using quantitative real-time PCR, and 9 CNVs had the same CNV types as predicted, with an accuracy of 90%. Based on GWAS, we identified 2 CNVs potentially associated with plumage color variations, with the associated CNV regions covering 9 genes. Enrichment analysis of these 9 candidate genes showed significant enrichment of 3 pathways (ribosome biogenesis in eukaryotes, RNA transport, and protein export) and 17 gene ontology terms. Among these, VWA5A can downregulate MITF by binding to the regulatory factors SOX10. The occurrence of CNV may indirectly contribute to duck plumage color variation by affecting the regulatory factors of the switch gene MITF in the melanogenesis pathway. These findings have improved the understanding of the genetic basis of duck plumage color variation and have been beneficial for developing and using plumage color traits in subsequent poultry breeding.

Disentangling ecological drivers of interspecific achromatic plumage variation in birds

AbstractAimUnderstanding the ecological determinants of interspecific achromatic (light‐to‐dark) plumage variation in birds is crucial yet challenging due to the complex interplay of climatic, habitat‐related, and morphological influences. This study aimed to disentangle the effects of temperature, precipitation, habitat openness, body mass and hand‐wing index (HWI, a widely used single‐parameter proxy for the extent to which a species relies on flight) on shaping achromatic plumage variation among bird species.LocationGlobal.Time PeriodContemporary.Major Taxa StudiedBirds.MethodsBased on data from over 8000 sessile bird species globally, we employed phylogenetic linear regressions to account for achromatic plumage colour in relation to temperature, precipitation, habitat openness, body mass and HWI, while correcting for phylogenetic non‐independence between species. Furthermore, we conducted phylogenetic path analyses to decompose direct from indirect effects.ResultsWe found that temperature, precipitation, habitat openness and body mass exerted separate but interactive effects on the variation in achromatic colour across species. Species inhabiting cold, wet or densely vegetated environments were darker coloured, while smaller species were lighter. Darker plumage was more strongly related to higher precipitation in colder regions for nocturnal species. For diurnal species, darker plumage was more closely associated with higher precipitation in more open habitats, whereas lighter plumage was more linked to lower mass in denser habitats. Noteworthy was the identification of a substantial correlation between achromatic colour and HWI. Diurnal species that are more aerial were lighter. Conversely, nocturnal flyers, especially females, tended to be darker.Main ConclusionsThe findings highlight the multifaceted nature of plumage coloration evolution, with adaptations for thermal efficiency, crypsis, signalling, waterproofing or protection against bacteria. However, the variable relative importance of these factors among groups emphasizes the significance of each factor in different contexts.

Contrary to phylogenetic predictions, crown coloration of the Eared Dove is not regulated by sex hormones

The mechanisms regulating plumage coloration appear to be phylogenetically conserved in avian species: the plesiomorphic character state is estrogen-dependent regulation, while testosterone, luteinizing hormone, and non-hormonal control are derived states. Limited data exist on the underlying regulatory processes of sexual dichromatism in the Eared Dove ( Zenaida auriculata (Des Murs, 1847)). Since the Columbiformes order is close to basal branches, we hypothesized that estrogen and testosterone play a central role in the regulation of crown plumage coloration in the Eared Dove. To test this, we subjected adult males to a forced molt accompanied by an exogenous increase of estradiol and testosterone to determine whether the presence of these hormones during molting modified the spectrophotometric characteristics of the plumage. No significant differences were found between treatments and controls in the colorimetric variables hue, ultraviolet saturation, and brightness. Similarly, the avian visual model showed no perceptible changes in chromatic and achromatic signals in the individual male adults. We also analyzed the effects of estrogen and testosterone on the growth speed of the new feathers. The hormone-treated groups increased in the speed of molting compared to the control group. These results suggest that the Eared Dove is an exception to basal branch models: rather than regulating coloration, sex hormones speed up the growth of the new feathers.

The Impact of Different Plumage Color Selected Quail Lines on Egg Quality and Eggshell Properties

The Impact of Different Plumage Color Selected Quail Lines on Egg Quality and Eggshell Properties

Digest: Asymmetrical introgression of belly coloration across a manakin hybrid zone in Panama.

How does sexual selection impact introgression dynamics across a hybrid zone? Long et al. (2024) used historical (1989-1994) and contemporary (2017-2020) samples to quantify the stability of a Panamanian hybrid zone between golden-collared manakins (Manacus vitellinus) and white-collared manakins (M. candei). Their analyses revealed a spatially stable hybrid zone, except for one trait, belly plumage coloration, which has introgressed into the distribution of the white-collared manakin. This finding suggests possible sexual selection for this trait.

Effect of Plumage Colour on The Productive and Physiological Performance of Two Lines of Turkey During Egg Production Period

Using 32 hens from two turkey lines; broad-breasted bronze (BBB) and bourbon red (BR), this study assessed how plumage colour affects egg production and physiological functions during (26-40) weeks of observation. A total of 32 hens, namely 16 hens from the BBB line and 16 hens from the BR line, were bred from 26 weeks up to 40 weeks of age. According to our results, BBB line significantly (p≤0.05) outperformed BR line in terms of body weight at first egg production, feed intake, and yolk diameter during the study period. A significantly (p≤0.05) higher feed conversion ratio, an increased egg mass, a higher production rate of hen-day eggs, and a higher rate of albumen was achieved by the BR line. It is, however, noteworthy that the age at first egg production, the egg weight, the egg mass, the yolk weight, the yolk percentage, the albumen weight, the shell weight percentage, the egg shell thickness, width, and length, the shape index, yolk height and yolk index were not significantly (p≥0.05) different between the two lines at 24 and 36 weeks of age. The levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were not significantly (p≥0.05) different between the two lines at 24 and 36 weeks of age when eggs were produced. Both turkey lines presented in the current study can potentially be raised in Iraq, as well as used as hens to produce hatching eggs and for genetic improvement.

Investigation into the association of FNDC1 and ADAMTS12 gene expression with plumage coloration in Muscovy ducks.

To elucidate the molecular genetic mechanisms underpinning feather color in Muscovy ducks. A cohort of 100 Muscovy ducks was meticulously selected for this research. Follicular tissues from ducks exhibiting black and white plumage served as the experimental samples. From these tissues, RNA and proteins were extracted for further analysis. The RNA underwent reverse transcription polymerase chain reaction amplification, followed by validation through western blot assays. The data revealed a significant upregulation in the expression of FN domain-containing protein 1 (FNDC1) and ADAMTS12 genes in Muscovy ducks with white plumage traits as opposed to those with black plumage traits. Specifically, individuals with pure white plumage demonstrated a markedly elevated expression of the FNDC1 gene in comparison to their pure black counterparts. Conversely, expression levels of the ADAMTS12 gene were found to be reduced in ducks with pure black plumage relative to those with pure white plumage. Notably, the expression patterns of FNDC1 and ADAMTS12 genes exhibited inconsistencies between mRNA and protein levels. This study offers significant insights into the molecular genetic mechanisms underlying feather color variation in Muscovy ducks. FNDC1 and ADAMTS12 could be considered potential targets for genetic manipulation or selective breeding strategies aimed at achieving specific feather color phenotypes in Muscovy ducks.

Observation of a Middle Spotted Woodpecker Dendrocoptes medius with aberrant, brown-coloured plumage

Abstract Birds with atypical colours in their plumage are not uncommon however, the potential causes of such aberrations have not been widely examined. Aberrant brownish-rufous phaeomelanin is one type of plumage colour that has been recorded in numerous bird species, including those which essentially contain only eumelanin (black) pigments, including several European woodpeckers. A Middle Spotted Woodpecker Dendrocoptes medius with aberrant phaeomelanised plumage observed in the Bükk Hills, Hungary, is detailed here and an evaluation of the possible nature of this form of plumage discussed.

Prediction of individual differences in non-iridescent structural plumage colour from nanostructural periodicity and regularity.

Non-iridescent structural plumage reflectance is a sexually selected indicator of individual quality in several bird species. However, the structural basis of individual differences remains unclear. In particular, the dominant periodicity of the quasi-ordered feather barb nanostructure is of key importance in colour generation, but no study has successfully traced back reflectance parameters, and particularly hue, to nanostructural periodicity, although this would be key to deciphering the information content of individual variation. We used matrix small-angle X-ray scattering measurements of intact, stacked feather samples from the blue tit crown to estimate the sex-dependence and individual variation of nanostructure and its effects on light reflectance. Measures of nanostructural periodicity successfully predicted brightness, ultraviolet chroma and also hue, with statistically similar effects in the two sexes. However, we also observed a lack of overall effect of the nanostructural inhomogeneity estimate on reflectance chromaticity, sex-dependent accuracy in hue prediction and strong sex-dependence in position estimation error. We suggest that reflectance attributes are modified by other feather structures in a sex-specific manner, and that within-individual variation in nanostructural parameters exists within or among feathers and this confounds the interpretation of structure-reflectance relationships at the plumage area level.

Identification of Differentially Expressed Genes and microRNAs in the Gray and White Feather Follicles of Shitou Geese.

The Shitou goose, a highly recognized indigenous breed with gray plumage originating from Chaozhou Raoping in Guangdong Province, China, is renowned for being the largest goose species in the country. Notably, during the pure breeding process of Shitou geese, approximately 2% of the offspring in each generation unexpectedly exhibited white plumage. To better understand the mechanisms underlying white plumage color formation in Shitou geese, we conducted a comparative transcriptome analysis between white and gray feather follicles, aiming to identify key genes and microRNAs that potentially regulate white plumage coloration in this unique goose breed. Our results revealed a number of pigmentation genes, encompassing TYR, TYRP1, EDNRB2, MLANA, SOX10, SLC45A2, GPR143, TRPM1, OCA2, ASIP, KIT, and SLC24A5, which were significantly down-regulated in the white feather follicles of Shitou geese. Among these genes, EDNRB2 and KIT emerged as the most promising candidate genes for white plumage coloration in Shitou geese. Additionally, our analysis also uncovered 46 differentially expressed miRNAs. Of these, miR-144-y may play crucial roles in the regulation of feather pigmentation. Furthermore, the expression of novel-m0086-5p, miR-489-y, miR-223-x, miR-7565-z, and miR-3535-z exhibits a significant negative correlation with the expression of pigmentation genes including TYRP1, EDNRB2, MLANA, SOX10, TRPM1, and KIT, suggesting these miRNAs may indirectly regulate the expression of these genes, thereby influencing feather color. Our findings provide valuable insights into the genetic mechanisms underlying white plumage coloration in Shitou geese and contribute to the broader understanding of avian genetics and coloration research.