Plumage Types Research Articles

The first case of bilateral gynandromorphic plumage type in the bearded reedling Panurus biarmicus

Bilateral gynandromorphism is a condition in which an individual has both male and female phenotypes distributed symmetrically on the body. We describe the first case of a likely gynandromorphic bearded tit, which was trapped in Poland. The bird had a black moustache and grey-blue plumage on the right side of the head, which is typical for males, and lacked this plumage coloration on the left side, which is typical of females. The entire bill was brown, consistent with a typical female, while the undertail coverts were buff with randomly distributed black spots, which represents a mixture feature of both sexes. The observation is discussed in light of earlier cases of gynandromorphic birds.

Feather characteristics of loral zone in an insectivorous passerine: The Iberian gray shrike Lanius meridionalis, in southern France.

In the French Mediterranean plain, the northern extreme of its native range, the Iberian gray shrike, Lanius meridionalis, predominantly feeds on arthropods. Its type of loral plumage plays a key role in protecting its eyes while transporting large prey. The aims are to understand the role played by feathers in protecting the animal from various types of defensive prey. I combine an inspection of large insect prey types found on larders with a review of bird specimens found in museum collections to examine the morphometric characteristics of rictal feathers and culmen. In addition, precision photographs are used to observe the posture of the plumage in natura. Icould identify four categories of protective feathers: clustered bristles, semi-bristles, semi-plumes distributed in the loral area, and semi-plumes above the eyes. My results suggest that the Iberian gray shrike has a complex structure of loral feathers, specific to its foraging activity and prey types. The presence of these rictal bristles is probably a protection against the movements of larger prey items, which might damage loral zone of Lanius meridionalis.

Intersexual social dominance mimicry drives female hummingbird polymorphism.

Female-limited polymorphisms, where females have multiple forms but males have only one, have been described in a variety of animals, yet are difficult to explain because selection typically is expected to decrease rather than maintain diversity. In the white-necked jacobin (Florisuga mellivora), all males and approximately 20% of females express an ornamented plumage type (androchromic), while other females are non-ornamented (heterochromic). Androchrome females benefit from reduced social harassment, but it remains unclear why both morphs persist. Female morphs may represent balanced alternative behavioural strategies, but an alternative hypothesis is that androchrome females are mimicking males. Here, we test a critical prediction of these hypotheses by measuring morphological, physiological and behavioural traits that relate to resource-holding potential (RHP), or competitive ability. In all these traits, we find little difference between female types, but higher RHP in males. These results, together with previous findings in this species, indicate that androchrome females increase access to food resources through mimicry of more aggressive males. Importantly, the mimicry hypothesis provides a clear theoretical pathway for polymorphism maintenance through frequency-dependent selection. Social dominance mimicry, long suspected to operate between species, can therefore also operate within species, leading to polymorphism and perhaps similarities between sexes more generally.

Morphological variation in the Black Falcon Falco subniger

We describe and discuss a field observation of a strongly speckle-breasted and barred Black Falcon Falco subniger that also, unusually, had yellow feet and cere and pale-yellow orbital rings. We also found several museum specimens with ‘variegated’ plumage and yellow bare parts. We speculate that yellow bare parts in this species might occur only in some individuals, perhaps mostly males, of the most variegated (pale-marked) plumage types, and that these correlated features may be age-related characters that deserve further investigation. We also discuss the implications for field identification.

Book Review

Book Review

Learning in advance? Interspecific recognition ability in male Eurasian blackcaps

Interspecific aggression is common in bird communities. It is thought to be a consequence of learned behavior or misdirected intraspecific aggression. In the former case birds acquire the ability to identify individuals of other species by social learning of species-specific traits during interactions with heterospecifics in a shared habitat. I conducted a two-choice song playback experiment to investigate the role of associating signals from two sensory modalities, auditory and visual, in shaping the agonistic response of male Eurasian Blackcaps (Sylvia atricapilla) to simulated male Garden Warbler (S. borin) intruders. I measured focal males’ response to playbacks to the song of a Blackcap or a Garden Warbler while giving them a choice between stuffed male models of both species presented in their territories. The experiments were carried out in early spring, before the arrival of Garden Warblers from Africa. I found that male Blackcaps were able to associate species-specific songs with species-specific plumage types. The ability to associate signals characterized not only experienced after-second-year old males, but also second-year old males that had not had the opportunity to defend breeding territories against heterospecifics. This suggests that second-year old male Blackcaps acquire the ability to associate Garden Warbler song with plumage before they use this skill when defending territory during their first breeding episode. Male Blackcaps do not mistake male Garden Warblers for males of their species, but rather learn these associations during the first months of life. However, the possibility that these associations are innate cannot be excluded.

Relationship between plumage color and eggshell patterns with egg production and egg quality traits of Japanese quails.

Aim:This study was conducted to identify the diversity of feather color and to determine the relationship between plumage color and egg yield as well as eggshell patterns and internal egg quality traits of Japanese quails.Materials and Methods:For investigating phenotypic diversity, a total of 600 quails from five breeding farms were evaluated to record head feather, shank, and plumage color. An on-station experiment was also conducted on 360 laying quails to examine the relationship between plumage color and egg production and egg weight during 24 weeks of laying. Eggs collected during this period were also used for identifying eggshell patterns and examining their relationship with internal egg quality characteristics.Results:Plumage color was primarily wild-type, with the highest proportion being 56.3% (p<0.001). Brown color was also found at a relatively high proportion in the population (16.7%), followed by black color (11.3%). The egg production and laying rate of quails with wild-type and brown plumage colors also significantly (p=0.001) differed from those of quails with other plumage types. Egg weight was also higher in these quail groups, especially than that of quails with yellow plumage color. Four patterns of eggshell were identified, among which spotted and dark eggshells were predominant (45.2% and 43.1%, respectively); however, patterns did not affect internal egg quality characteristics.Conclusion:Plumage color was primarily wild-type in both male and female quails. Egg yield over a 24-week laying period was superior in quails with wild-type and brown plumage colors, whereas a relationship between eggshell patterns and egg quality traits could not be established.

Effect of feathering genes on growth performance of F2 backcrosses and comparison of F1 and F2 crosses of Abor Acre broiler breeder x native chickens in humid tropical environment

This study was conducted to evaluate growth performance, brooding and rearing mortalities of F2 main and reciprocal backcross progenies of Abor Acre broiler breeder x native chicken crosses and to compare their F1 and F2 backcross progenies. The base population used in the study consisted of mature (~ 48 weeks) male and female native chickens and exotic (Abor Acre) broiler breeder parent stock. The native chicken varieties were made up of normal feather, naked neck and frizzle genotypes. These birds were mated to the Abor Acre broiler parent stocks in main and reciprocal fashion generating F1 main and reciprocal crossbreds. Females of these F1 hybrids were then mated back to the broiler breeder cock to generate F2 main and reciprocal backcross progenies that were evaluated in the present study. Data analyzed include body weight (BWT) and linear body parameters (LBPs), average feed intake (AFI), feed conversion ratio (FCR), brooding and rearing mortalities. Comparisons between genetic groups for these parameters were done by means of analysis of variance (ANOVA) technique. Results indicated improved growth performance and feed conversion ratios in the F2 reciprocal backcross groups compared to their F2 main backcross counterparts. The F2 individuals in both crosses were superior to F1 crossbred populations. Chick mortality rates were higher in main and reciprocal backcross groups involving the naked neck genotype compared to other plumage types. It was concluded that backcrossing the F1 individuals to the exotic broiler breeder cocks increased the genetic profile of the backcross lines resulting in enhanced growth performance of progenies. Crossbreeding of exotic and local chicken varieties generated progenies that had higher genetic potentials for growth relative to the local strains and better adaptability relative to the exotic breed. However, incubation and brooding strategies capable of minimizing mortalities at embryonic, brooding and rearing phases should be explored and integrated in local chicken improvement programmes involving the use of these plumage reducing genes for optimal results.

Inheritance of plumage colour in the F1 and test cross progeny of Japanese quail

Recessive genes produced its phenotypic effect only when its allele is identical while the dominant ones produced its effect either with identical or dissimilar alleles. This study was conducted to determine the mode of inheritance of plumage colour in Japanese quail flock in Nigeria, using the Manchurian Gold (MG), Pharaoh (PH) and Panda White (PW) plumage types. All possible crosses were made among the three colour variants making a total of nine mating groups. A total number of 2,348 F1 chicks and 1,563 test cross progeny obtained from the incubated eggs were classified and counted by their down colour into observable plumage colour groups. The expected phenotypic ratios of the F1 and test cross progeny were computed based on the assumption that parents that were homozygous for a particular plumage colour breed true. The results revealed that the Pharaoh plumage quails carry the wild-type allele (Wb) in homozygous form or in heterozygous with the Panda White (wb) allele. The Manchurian gold plumage quails carry the Manchurian Gold-type allele (Wb+) in heterozygous with either Wb or wb. All the Panda White chicks were homozygous for the wb allele, which was recessive to both Wb and Wb+ alleles. The Chi-square results confirm the heterozygousity of the dominant phenotype in the test crosses. It can be concluded that inheritance of plumage colour is controlled by autosomal genes with dominant hierarchy of MG&gt; PH&gt; PW (Wb+ &gt;Wb&gt;wb).

Birds of the Oceans and Waterways

Birds of the Oceans and Waterways

New record of erythrism in Psittacara leucophthalmus (Statius Muller, 1776) (Psittaciformes: Psittacidae) in Southern Minas Gerais state, Southeastern Brazil

The scientific literature mentions that neotropical birds of the family Psittacidae have some tendencies to natural and artificial changes in its plumage colours. In studies of plumage aberrant of the parrots were categorized six terms: albinism, eritrism, leucism, xantocroism, cyanism and melanism. We present a rare case of erythrism in species of Brazilian native parrot [Psittacara. leucophthalmus (Statius Muller, 1776)]; therefore, there is only a report of this type of aberrant plumage for Amazona aestiva (Linnaeus, 1758) and for an African species of the genus Agapornis, thus highlighting the importance of this record.

Local poultry populations in Chlef (Algeria): phenotypes, rearing systems and performances.

The local chickens represent a very important source of income and high quality protein for rural households all over the world and especially in the poorest African countries. In Algeria, the local poultry populations is a valuable source of income and play a significant cultural role; they are thus offered as gifts and used during ritual sacrifices or ceremonies. Despite their economic and cultural importance, Algerian local breeds being exploited only in family farms, remain poorly known. In order to document and identify the phenotypic characteristics of the local poultry populations in the region of Chlef, several surveys were conducted on 72 families. Socioeconomic results showed that all women (100%) were housewives; and they were the key player (80%) in the chicken-farming activity. The chickenrearing conditions were very rudimentary, characterized by an inadequate housing (73.5%), insufficient quantity of food (75%), uncontrolled reproduction scheme and a complete lack of veterinary assistance, leading to significant losses mainly due to diseases (52%) and predation (31%). The observation and analysis of 677 animals led to the identification of several phenotypes; the white, straw, red and golden were the most dominant plumage colors, the smooth feathers was the most frequent (92.8%) type of plumage and the normal distribution of plumage prevailed with 83.8%. The average weight comparison showed a very significant sexual dimorphism (p &lt; 0.0001) in favor of males. The improvement of rearing conditions remains the best solution to improve productivity.

Timing and body condition of dichromatic Black Redstarts during autumn migration.

Individual variation in postjuvenile molt in male Black Redstart is pronounced with about 90% of young males retaining female‐like coloration (cairei plumage type) and about 10% acquiring adult male‐like feathers (paradoxus plumage type). We examined whether autumn migration timing and body condition differed between individuals of the two plumage types. We used the data of 10,977 Black Redstarts captured during autumn at a ringing site in northern Switzerland where a protocol to record plumage types of captures has been applied since 1980. As cairei individuals cannot be distinguished from young females while sexing is comparatively easy for paradoxus individuals, the proportion of missing data on sex was likely to be higher for cairei individuals than for paradoxus individuals. We formally accounted for captures with unidentified sex using a Bayesian approach and conducted a simulation study to show that our approach was able to provide unbiased results even if the proportion of unsexed captures was high. Applying the method to the Black Redstart data, we found that the proportion of individuals with paradoxus plumage type increased from 7.6% in 1980 to 18.1% in 2013. Individuals with the paradoxus plumage type were on average 0.25 g heavier and had 0.62 mm longer third primaries than individuals with the cairei plumage type. However, we found no support for our expectation of later migration of paradoxus males compared to cairei individuals based on the assumption that paradoxus individuals should occupy autumn territories like adult males. Our results shed new light on the understudied timing of autumn migration in birds and are in line with available studies on Black Redstarts, suggesting a molt‐constraint that allows only young males in good body condition to molt into adult‐like plumages.

Mummified precocial bird wings in mid-Cretaceous Burmese amber.

Our knowledge of Cretaceous plumage is limited by the fossil record itself: compression fossils surrounding skeletons lack the finest morphological details and seldom preserve visible traces of colour, while discoveries in amber have been disassociated from their source animals. Here we report the osteology, plumage and pterylosis of two exceptionally preserved theropod wings from Burmese amber, with vestiges of soft tissues. The extremely small size and osteological development of the wings, combined with their digit proportions, strongly suggests that the remains represent precocial hatchlings of enantiornithine birds. These specimens demonstrate that the plumage types associated with modern birds were present within single individuals of Enantiornithes by the Cenomanian (99 million years ago), providing insights into plumage arrangement and microstructure alongside immature skeletal remains. This finding brings new detail to our understanding of infrequently preserved juveniles, including the first concrete examples of follicles, feather tracts and apteria in Cretaceous avialans.

Revisiting the condition‐dependence of melanin‐based plumage

Support against the condition‐dependence of melanin plumage signals has relied on data from species exhibiting both melanin‐ and carotenoid‐based plumage ornaments. As the mechanisms leading to variation in carotenoid‐ and melanin‐based plumage differ fundamentally, these systems may not be ideal to assess the condition‐dependence of melanin signals. Instead, we hypothesized that melanin‐plumage is more likely to signal condition in purely achromatic species. We performed a meta‐analysis reviewing evidence for condition‐dependent melanic plumage: we compared the net effect size for the relationship between melanin traits and condition in species that are achromatic versus species that also display a carotenoid‐based trait. Our results indicate that melanin plumage is condition‐dependent in species of both plumage types. Contrarily to our prediction, this finding suggests that melanin ornament condition‐dependence is not conditional on the context of other ornaments within a species. Instead, melanin ornaments should be viewed as potential condition‐dependent signals in all species.

Color differences among feral pigeons (Columba livia) are not attributable to sequence variation in the coding region of the melanocortin-1 receptor gene (MC1R)

BackgroundGenetic variation at the melanocortin-1 receptor (MC1R) gene is correlated with melanin color variation in many birds. Feral pigeons (Columba livia) show two major melanin-based colorations: a red coloration due to pheomelanic pigment and a black coloration due to eumelanic pigment. Furthermore, within each color type, feral pigeons display continuous variation in the amount of melanin pigment present in the feathers, with individuals varying from pure white to a full dark melanic color. Coloration is highly heritable and it has been suggested that it is under natural or sexual selection, or both. Our objective was to investigate whether MC1R allelic variants are associated with plumage color in feral pigeons.FindingsWe sequenced 888 bp of the coding sequence of MC1R among pigeons varying both in the type, eumelanin or pheomelanin, and the amount of melanin in their feathers. We detected 10 non-synonymous substitutions and 2 synonymous substitution but none of them were associated with a plumage type. It remains possible that non-synonymous substitutions that influence coloration are present in the short MC1R fragment that we did not sequence but this seems unlikely because we analyzed the entire functionally important region of the gene.ConclusionsOur results show that color differences among feral pigeons are probably not attributable to amino acid variation at the MC1R locus. Therefore, variation in regulatory regions of MC1R or variation in other genes may be responsible for the color polymorphism of feral pigeons.

Detecting change in the status and habitat of Hinde's BabblerTurdoides hindei: 2000 to 2011

Department of Zoology, National Museums of Kenya,PO Box 40658-00100, Nairobi, KenyaBACKGROUNDThe globally Vulnerable Kenyan endemic Hinde’s Bab-bler Turdoides hindei has its stronghold in the foothills ofMt Kenya and the Aberdares, where it is associatedmainly with patches of scrub and riverine thicket (Statt-ersfield et al. 1998, Njoroge & Bennun 2000, BirdLifeInternational 2012). A decline in its known range, firstdescribed in the 1970s, was attributed to scrub clearancefor cultivation, perhaps compounded in some areas byhuman disturbance and hunting (Plumb 1979, Njorogeet al. 1998). Surveys in 1994 and 2000–2001 showedthat the species was much less abundant within pro-tected areas than in fertile, densely populated farmland,offering limited scope for conservation through furthersite designation (Shaw & Musina 2003).The global range of Hinde’s Babbler lies predomi-nantly within the catchments of the upper Tana River,with outlying populations in Meru District, Machakos,Kitui and Nziu (Shaw et al. 2003). By 2001 the specieswas known from just seven main areas, and was thoughtto have a global population of c. 1500–5600 birds.Although scrub clearance has impacted on the species’range and population, its effect may have been partlymitigated by the spread of the exotic invasive Lantanacamara, which provides scrub cover in areas previouslycleared of native shrubs, enabling the Babbler to persistin, and possibly to re-colonize, intensively farmed land(Njoroge & Bennun 2000).Like most members of its genus, Hinde’s Babblerbreeds cooperatively, groups typically comprising threeto four adults (range 1–8), often accompanied by one ortwo juveniles (Njoroge & Mutinda 1996, Shaw & Musi-na 2003). Some groups include individuals with exten-sive light feathering on the chest, head and back,sometimes distributed asymmetrically, a trait interpretedby Plumb (1979) as possible evidence of inbreeding.In 2011 we reassessed the global range of Hinde’sBabbler and resurveyed three sites previously surveyedin 2000–2001, to determine whether changes hadoccurred in its known range, abundance, demography orhabitat over the intervening decade. To determine therelationship between plumage type, population densityand breeding success we assigned a plumage score to allindividuals seen sufficiently clearly, noting their age classand group composition.GLOBAL RANGEChanges in Hinde’s Babbler’s global range were estimatedfrom the number of occupied 10 9 10-km squares (itsArea of Occupancy) and from the number of squaresbounded by these known sites (its Extent of Occurrence).Three time periods were compared: 1900–1970,1971–1990 and 1991–2011. Since its discovery in 1900,Hinde’s Babbler has been recorded in 53 squares, indicat-ing an Area of Occupancy of c. 5300 km

The role of ecological variation in driving divergence of sexual and non-sexual traits in the red-backed fairy-wren (Malurus melanocephalus)

BackgroundMany species exhibit geographic variation in sexual signals, and divergence in these traits may lead to speciation. Sexual signals may diverge due to differences in ecology if the environment constrains signal production or transmission. Alternatively, sexual signals may diverge stochastically through sexual selection or genetic drift, with little environmental influence. To distinguish between these alternatives we quantified variation in two putative sexual signals – tail length and plumage color – and a suite of non-sexual morphometric traits across the geographic range of the red-backed fairy-wren (Malurus melanocephalus). We then tested for associations between these traits and a number of environmental variables using generalized dissimilarity models.ResultsVariation in morphometric traits was explained well by environmental variation, irrespective of geographic distance between sites. Among putative signals, variation in plumage color was best explained by geographic distance, whereas tail length was best explained by environmental variation. Divergence in male plumage color was not coincident with the boundary between genetic lineages, but was greatest across a contact zone located 300 km east of the genetic boundary.ConclusionsMorphometric traits describing size and shape have likely been subject to ecological selection and thus appear to track local environmental variation regardless of subspecies identity. Ecological selection appears to have also influenced the evolution of tail length as a signal, but has played a limited role in shaping geographic variation in plumage color, consistent with stochastic divergence in concert with Fisherian selection on this trait. The lack of coincidence between the genetic boundary and the contact zone between plumage types suggests that the sexual plumage signal of one subspecies has introgressed into the genetic background of the other. Thus, this study provides insight into the various ways in which signal evolution may occur within a species, and the geographic patterns of signal variation that can arise, especially following secondary contact.

Spatial decoupling of song and plumage generates novel phenotypes between 2 avian subspecies

Sexual signals can be important mechanisms of reproductive isolation among incipient species, but the relative effectiveness and geographic distribution of different signals may vary, particularly when those signals have different modes of inheritance (e.g., cultural vs. genetic). Indeed, novel phenotypes may develop when traits with different modes of inheritance or different selection pressures become spatially decoupled from one another in zones of secondary contact, and such novel phenotypes may facilitate or hinder reproductive isolation. We assessed divergence of a culturally transmitted signal (song) and conspecific responses to that signal across a zone of reduced gene flow where plumage characters show asymmetrical introgression among subspecies of the red-backed fairy-wren (Malurus melanocephalus). We found that, in contrast to plumage, geographic variation in many song characteristics correlated well with geographic genetic structure. Additionally, playback experiments revealed that birds responded most strongly to songs from within the same genetic region irrespective of plumage type. These results indicate that song has been resistant to introgression, yet song traits and preferences have not hindered introgression of plumage traits. We suggest that this is because different modes of inheritance (here, cultural vs. genetic) facilitate decoupling of song and plumage, resulting in a large region where males exhibit a novel combination of sexual traits.

Plumage reflectance signals dominance in Florida scrub-jay, Aphelocoma coerulescens, juveniles

Although sexual selection is undeniably important in the evolution and maintenance of ornamental traits, it remains an unsuitable explanation for juvenile ornamentation. Male–male competition has been important in the evolution of UV-blue plumage ornamentation in birds, suggesting that this type of plumage may signal status more generally. In the present study, we compared dominance status of juvenile Florida scrub-jays before and after experimental plumage manipulation and found that plumage reflectance signalled status. Male–male competition is important in maintaining UV-blue plumage ornamentation in adults of other species. However, our evidence shows that sexually dimorphic ornamentation can also mediate competition over food resources in juvenile Florida scrub-jays. Understanding status signalling among juveniles may yield insights into differences in fitness, especially in species with cohesive social systems where early interactions are likely to influence future competitions over resources or mates. ► We experimentally manipulated plumage reflectance of juvenile Florida scrub-jays. ► We compared dominance before and after plumage manipulation. ► We found that reducing plumage reflectance caused a reduction in dominance. ► We conclude that plumage reflectance signals status in juvenile Florida scrub-jays.