Pelage Color Research Articles

Examination of Cranial and Pelage Color Variation between Two Subspecies of Gray Squirrel (Sciurus carolinensis)

Whether cranial measurements or pelage color is most appropriate for identifying two subspecies of gray squirrel (Sciurus c. carolinensis and S. c. fuliginosus) has been a matter of debate. The objective of this research was to examine populations of gray squirrels in Louisiana, Arkansas, and Mississippi to determine which aspects of variation are more useful for identifying subspecies. Cranial variation was assessed using 14 cranial measurements of museum specimens. Pelage color was assessed from digital pictures of the dorsal pelage. We used multivariate analysis of variance (MANOVA) to test for differences in cranial and pelage color variation. Cranial size was significantly different among populations of gray squirrels, with a north to south cline of larger to smaller individuals. However, we were not able to definitively assign populations in the zone of intergradation to a subspecies based on cranial morphology. Pelage color showed no discernable pattern of geographic variation among populations. Based on these results, we suggest that the differences observed among populations could be due to clinal variation and the legitimacy of S. carolinensis subspecies is tentative at best.

The Serine Protease Activity of Corin Is Required for Normal Pigment Type Switching

The Serine Protease Activity of Corin Is Required for Normal Pigment Type Switching

Phylogeny and taxonomic reassessment of jerboa,Dipus(Rodentia, Dipodinae), in inland Asia

AbstractDeserts and arid regions are perceived to have low biological and genetic diversity, which has partially influenced the identification of psammophilic species, especially taxonomic inferences based on morphology alone. Recent studies ofDipus sagittahave revealed clear, deep genetic divergence beyond the species level within this monotypic genus. To clarify the taxonomy ofDipus, we examined a morphometric dataset consisting of 191 voucher specimens covering nearly the entire distribution of the genus to explore skull variation using traditional morphological measurements and geometric morphometric analysis. Phylogenetic relationships withinDipususing two mitochondrial genes (n = 383) and six nuclear genes (n = 106) were assessed by Bayesian inference and maximum‐likelihood procedures. We used a “candidate species approach” with the divergent mtDNAphylogenetic groups and subspecies identified in previous studies as the starting point and analysed the candidates using five species delimitation methods and two validation methods. Our findings indicate thatDipuscan be divided into four phylogenetic groups that include two species: the Deasyi group (D. deasyi), Sagitta group, Sowerbyi group and Turanicus group (D. sagitta). According to the morphological analyses and the examined specimens, pelage colour varies significantly with season and age, making it unsuitable as a diagnostic characteristic of the subspecies. Furthermore, measurements of body size and skull size require a large number of specimens to reach statistical significance and obtain reliable results. Geographical distributions should be considered first when identifying species or subspecies due to the disjunct habitats ofDipus. Our molecular analyses revealed the long‐neglected potential diversity in arid regions and improved the efficiency of species/subspecies identification. We also found that individuals from more humid areas or higher altitudes were larger, whereas individuals from drier areas possessed longer appendages and larger tympanic bulla.

The first record of mitochondrial haplotypes of Gazella marica (Artiodactyla, Bovidae) in wild populations in Iran

Iran with its highly structured landscape, such as the Zagros Mountain Range that stretches across the country from East to West, is home to at least three different gazelle species. For some of them, intraspecific genetic patterning is to be expected, as different populations show different pelage coloration or body sizes, e.g., in the Persian gazelle (G. subgutturosa). This species is especially interesting due to its taxonomic history, as it was considered to be conspecific with sand gazelle (G. marica) from Arabia until recently. G. marica and G. subgutturosa were even thought to intergrade/hybridize in a broad region from the Euphrates/Tigris basin to the Zagros Mountains. This area is inhabited by small gazelles that seem to be intermediate in size and other characters between the two species. However, so far all molecular studies showed that the mitochondrial haplotypes of gazelles in this supposed hybrid zone only belong to G. subgutturosa. We collected samples from four populations of Persian gazelles in Iran, in the eastern part of the Zagros Mountains. In two of these locations, we found mitochondrial haplotypes of G. marica, including one potentially pure natural population in Bushehr Province, and one reintroduced mixed population with G. marica and G. subgutturosa haplotypes in Khuzestan Province. It might therefore be possible that G. marica, which is phenomically most similar to G. subgutturosa, exits in Iran as a fourth gazelle species besides G. subgutturosa, G. bennettii, and G. arabica. We strongly recommend that future conservation management decisions, especially animal translocations, should be based on genetic analyses of the populations under consideration.

Climate change is affecting mortality of weasels due to camouflage mismatch

Direct phenological mismatch caused by climate change can occur in mammals that moult seasonally. Two colour morphs of the weasel Mustela nivalis (M. n.) occur sympatrically in Białowieża Forest (NE Poland) and differ in their winter pelage colour: white in M. n. nivalis and brown in M. n. vulgaris. Due to their small body size, weasels are vulnerable to attacks by a range of different predators; thus cryptic coat colour may increase their winter survival. By analysing trapping data, we found that the share of white subspecies in the weasel population inhabiting Białowieża Forest decreases with decreasing numbers of days with snow cover. This led us to hypothesise that selective predation pressure should favour one of the two phenotypes, according to the prevailing weather conditions in winter. A simple field experiment with weasel models (white and brown), exposed against different background colours, revealed that contrasting models faced significantly higher detection by predators. Our observations also confirmed earlier findings that the plasticity of moult in M. n. nivalis is very limited. This means that climate change will strongly influence the mortality of the nivalis-type due to prolonged camouflage mismatch, which will directly affect the abundance and geographical distribution of this subspecies.

Mitochondrial DNA Analyses of Cercopithecus Monkeys Reveal a Localized Hybrid Origin for C. mitis doggetti in Gombe National Park, Tanzania

In recent years, hybridization has gained recognition as an important creative force in primate evolution. The exchange of genetic material between species provides genetic novelty on which evolutionary forces, such as natural selection, may act. The guenon radiation (Tribe Cercopithecini) is known for numerous cases of contemporary hybridization—in the wild and captivity—between broadly sympatric species. Interspecific hybrids are viable, and field studies report fertile hybrid females. Despite being a well-documented phenomenon, hybridization among wild guenons is relatively rare and sporadic. An exception is the long-standing hybridization between Cercopithecus mitis doggetti and C. ascanius schmidti in Gombe National Park, Tanzania, where hybrids comprise a significant proportion of the breeding population. Here, I used mitochondrial loci to conduct a genetic survey of the Gombe population and examine the extent and direction of gene flow between the parental species. I extracted DNA from noninvasive fecal samples of unhabituated individuals (N = 144 individuals) with known phenotype and provenance. All parental phenotypes and hybrid individuals were identified in the field based on species specific pelage colors and patterns. Phylogenetic analyses of DNA sequences from inside and outside the hybrid zone show Gombe’s population of C. mitis doggetti is distinct from neighboring conspecific populations in having mitochondrial DNA of C. ascanius schmidti. All animals surveyed from the hybrid zone have one of two haplotypes of C. ascanius schmidti unique to Gombe. These results provide evidence of asymmetric introgressive hybridization between sympatric guenon species, a likely consequence of colonization patterns of the parental species during range expansions. The spatial distribution patterns of the two haplotypes imply that Gombe is a site of both historic and contemporary hybridization between sympatric guenons. The discovery of gene flow and ongoing hybridization between clearly defined species, ecologically distinct enough to coexist in broad sympatry, provides an ideal system to investigate speciation mechanisms in primate adaptive radiations.

A short review and worldwide list of wild albino rodents with the first report of albinism in Coendou rufescens (Rodentia: Erethizontidae)

Abstract Aberrant pelage color patterns such as albinism have been reported in some mammal groups including rodents, but in spite of the group’s richness, the phenomenon is relatively poorly documented in the literature. Albino specimens are reported in <2% of the species of rodents, four records of neotropical species were found (Delomys dorsalis, Heteromys anomalus, Octodon degus, Phyllotis andium). Of New World porcupines (Erethizontidae), albinism was documented only in the North American species Erethizon dorsatum. Here we report the first albino record from the Neotropics for this group, a stump-tailed porcupine (Coendou rufescens) in northern Ecuador.

How many pygmy marmoset (Cebuella Gray, 1870) species are there? A taxonomic re-appraisal based on new molecular evidence

The pygmy marmoset, Cebuella pygmaea, the smallest of the New World monkeys, has one of the largest geographical distributions of the Amazonian primates. Two forms have been recognized: Cebuella pygmaea pygmaea (Spix, 1823), and C. p. niveiventris Lönnberg, 1940. In this study, we investigated if the separation of pygmy marmosets into these two clades can be corroborated by molecular data. We also examine and compare coloration of the pelage in light of the new molecular results. We analyzed the mtDNA cytochrome b gene and, for the first time for any Neotropical primate, we used a reduced representation genome sequencing approach (ddRADseq) to obtain data for recently collected, geographically representative samples from the Rio Japurá, a northern tributary of the Rio Solimões and from the Javarí, Jutaí, Juruá, Madeira and Purus river basins, all tributaries south of the Solimões. We estimated phylogenies and diversification times under both maximum likelihood and Bayesian inference criteria. Our analysis showed two highly supported clades, with intraclade divergences much smaller than interclade divergences, indicating two species of Cebuella: one from the Rio Japurá and one to the south of Solimões. The interpretation of our results in light of the current taxonomy is not trivial however. Lönnberg stated that the type of Spix’s pygmy marmoset (type locality ‘near Tabatinga’) was obtained from the south of the Solimões, and his description of the distinct niveiventris from Lago Ipixuna, south of the Solimões and several hundred kilometres east of Tabatinga, was based on a comparison with specimens that he determined as typical pygmaea that were from the upper Rio Juruá (south of the Solimões). As such it remains uncertain whether the name pygmaea should be applicable to the pygmy marmosets north of the Rio Solimões (Tabatinga type locality) or south (near Tabatinga but across the Solimões). Finally, our analysis of pelage coloration revealed three phenotypic forms: (1) south of the Rio Solimoes, (2) Eirunepé-Acre, upper Juruá basin; and (3) Japurá. More samples from both sides of Solimões in the region of Tabatinga will be necessary to ascertain the exact type locality for Spix’s pygmaea and to resolve the current uncertainties surrounding pygmy marmoset taxonomy.

The evolution of anterior coloration in carnivorans

Some carnivorans have striking patches of fur on their faces (spots, bands, eye masks) and blazes on their chests that are primarily visible from a frontal view. We tested five hypotheses to explain the evolution of the complexity and contrast of these color patches. These were: signals of species identity to avoid hybridization, communication between conspecifics, signals used to warn of defensive anal secretions, signals of belligerence or pugnacity, and camouflage-related coloration used to break up the outline and facial features of the predator when approaching prey. Using phylogenetically controlled multifactorial analyses in six different families of carnivorans, examined separately, our analyses uncovered significant positive associations between measures of color pattern complexity and sociality across herpestid faces and canid chests, suggesting use in social communication. Mustelid facial color complexity was associated with ability to direct anal secretions accurately at predators, and facial markings were significantly or marginally associated with pugnacity in mustelids, viverrids, and herpestids. Facial complexity of viverrid and herpestid species was significantly or marginally related to a mammal-based diet. In ursids, facial contrast appeared less variable in species living in greater sympatry with other bears. Facial and chest coloration in Carnivora appears to have evolved under different selection pressures in different families. The reasons that many carnivorans have colorful and memorable faces and chests are not yet understood. Here, we pit five different hypotheses against each other: species recognition, advertising either toxic anal defenses or pugnacity, recognizing group members, and trying to remain concealed when approaching mammalian prey. We find that measures of facial and chest complexity and contrast have evolved for different reasons depending on the carnivoran family. Anterior coloration appears to be involved with social communication in herpestids and canids; facial coloration is associated noxious secretions in mustelids, with pugnacity in mustelids, viverrids and herpestids; with reliance on a mammal-based diet in viverrids and herpestids; and with avoiding hybridization in bear species. There is no overriding evolutionary explanation for varied facial and chest pelage coloration across carnivorans.

Replenishing Regulatory T Cells to HaltDepigmentation in Vitiligo.

Vitiligo is a cutaneous autoimmune disease, especially devastating to patients with darker skin tones because of the contrast between unaffected and lesional skin. We studied immune cells infiltrating vitiligo skin and found very few regulatory T cells (Tregs). Vitiligo was not associated with a reduced frequency or function of circulating Tregs. To manipulate Treg function, we used mouse models expressing melanocyte-reactive TCRs, following changes in pelage color. We also isolated splenocytes to measure Treg function and evaluated cutaneous Treg abundance. Even small numbers of Tregs transferred into depigmenting mice could effectively interfere with depigmentation. The same holds true for treatment with rapamycin, readily translatable for use in human patients; such treatment may be well tolerated. Because vitiligo skin is relatively devoid of cells that produce the chemokine CCL22, whereas circulating Tregs express normal levels of its receptor CCR4, we overexpressed Ccl22 inthe skin of vitiligo-prone mice to assess the resulting levels of depigmentation. Markedly reduced depigmentation was accompanied by Treg infiltration to the skin. With several options available to support ahealthy balance between Tregs and effector Tcells,the next challenge will be to render such treatment antigen specific and avoid general immunosuppression.

Do traditional sheep breeders perform conscious selection? An example from a participatory breeding program of Morada Nova sheep.

The implementation of sustainable breeding programs requires genetic breeding strategies that are appropriate for the reality production systems. It is also essential that the choice of animal selection criteria be based on breeders' knowledge and objectives. This work is an ethno-zootechnical study of the Morada Nova sheep breed and its crossbreeds. The goals of this study were to register and analyze indigenous breeders' knowledge and practices regarding animal selection criteria and to generate technical information to support a participatory breeding program of the breed. This study was conducted in the Morada Nova municipality in the state of Ceará, Brazil. Semi-structured interviews were evaluated using two groups of individuals, purebred Morada Nova sheep breeders (RMN, n=13) and breeders of Morada Nova crossbreeds (MMN, n=48). Interview questions were used to identify local selection criteria adopted by each group in the choice of animals for breeding. Data from the interviews were submitted to frequency distribution analysis and the Shapiro-Wilk test to verify their distribution. Later, the Kruskal-Wallis test was used to compare the two groups of farmers based on that information, in addition to multivariate statistical analysis and evaluation of Smith salience index. Breeders in the RMN group used selection criteria related to breed standards, such as pelage color. In contrast, breeders of the MMN group used criteria related to productivity, such as body conformation and milk production. Breeders should be engaged in the development of breeding programs, and it is important to consider their preferences and objectives when evaluating breeding animals.

Colour vision in Finlayson’s squirrel (Callosciurus finlaysonii): is conspicuous pelage colour useful for species recognition?

Finlayson’s squirrel, Callosciurus finlaysonii, is distributed in lowland forests throughout South-East Asia. Its pelage colour is conspicuous and polymorphic (red, black, white and a mixture of these colours), which is characteristic of the species, with 16 subspecies described based on pelage colour patterns. Two closely related species, the brown C. erythraeus and the orange C. caniceps, are also distributed throughout the region. To examine whether the conspicuous pelage colour is a visual clue for species/subspecies discrimination, we experimentally assessed the colour vision of C. finlaysonii. Optically measured pelage colours of the dorsal body differed greatly among seven subspecies of C. finlaysonii and also differed among the three species of the region. Colour vision tests revealed that C. finlaysonii can discriminate the colour of conspecific white, black, and red pelages from the orange pelages of C. caniceps. They can also discriminate the brown pelages of C. erythraeus and conspecific white...

The transcriptional landscape of seasonal coat colour moult in the snowshoe hare.

Seasonal coat colour change is an important adaptation to seasonally changing environments but the evolution of this and other circannual traits remains poorly understood. In this study, we use gene expression to understand seasonal coat colour moulting in wild snowshoe hares (Lepus americanus). We used hair colour to follow the progression of the moult, simultaneously sampling skin from three moulting stages in hares collected during the peak of the spring moult from white winter to brown summer pelage. Using RNA sequencing, we tested whether patterns of expression were consistent with predictions based on the established phases of the hair growth cycle. We found functionally consistent clustering across skin types, with 766 genes differentially expressed between moult stages. "White" pelage showed more differentially expressed genes that were upregulated relative to other skin types, involved in the transition between late telogen (quiescent stage) and the onset of anagen (proliferative stage). Skin samples from transitional "intermediate" and "brown" pelage were transcriptionally similar and resembled the regressive transition to catagen (regressive stage). We also detected differential expression of several key circadian clock and pigmentation genes, providing important means to dissect the bases of alternate seasonal colour morphs. Our results reveal that pelage colour is a useful biomarker for seasonal change but that there is a consistent lag between the main gene expression waves and change in visible coat colour. These experiments establish that developmental sampling from natural populations of nonmodel organisms can provide a crucial resource to dissect the genetic basis and evolution of complex seasonally changing traits.

A new subspecies of large-eared pika, Ochotona macrotis (Lagomorpha: Ochotonidae), from the Eastern Himalaya

We examined 212 complete sequences of the cytochrome b gene for all pika species (Lagomorpha: Ochotona) as well as 250 skulls of pikas from the eastern Himalayan region. The results of our analyses suggest that a new and distinct subspecies of large-eared pika — Ochotona macrotis gomchee ssp.n. occurs in Bhutan. Our phylogenetic analyses indicate that this subspecies holds a sister-taxon relationship to other O. macrotis. The cranial shape of O. m. gomchee ssp.n. is similar to that of remaining O. macrotis; pelage colouration and ear length differentiate O. m. gomchee ssp.n. from all other representatives of O. macrotis. We hypothesize that pikas from the Great Bend of the Tsangpo River, which were previously assigned to O. forresti, in fact belong to O. macrotis; the correct name for that particular subspecies is therefore amended to O. m. duoxionglaensis. The distributional ranges of O. m. gomchee ssp.n. and O. m. duoxionglaensis are hypothesized to be separated by a broad matrix of unsuitable habitats.

Reconstructing the molecular phylogeny of giant sengis (Macroscelidea; Macroscelididae; Rhynchocyon)

Giant sengis (Macroscelidea; Macroscelididae; Rhynchocyon), also known as giant elephant-shrews, are small-bodied mammals that range from central through eastern Africa. Previous research on giant sengi systematics has relied primarily on pelage color and geographic distribution. Because some species have complex phenotypic variation and large geographic ranges, we used molecular markers to evaluate the phylogeny and taxonomy of the genus, which currently includes four species: R. chrysopygus, R. cirnei (six subspecies), R. petersi (two subspecies), and R. udzungwensis. We extracted DNA from fresh and historical museum samples from all taxa except one R. cirnei subspecies, and we generated and analyzed approximately 4700 aligned nucleotides (2685 bases of mitochondrial DNA and 2019 bases of nuclear DNA) to reconstruct a molecular phylogeny. We genetically evaluate Rhynchocyon spp. sequences previously published on GenBank, propose that the captive R. petersi population in North American zoos is likely R. p. adersi, and suggest that hybridization among taxa is not widespread in Rhynchocyon. The DNA sample we have from the distinctive but undescribed giant sengi from the Boni forest of northern coastal Kenya is unexpectedly nearly identical to R. chrysopygus, which will require further study. Our analyses support the current morphology-based taxonomy, with each recognized species forming a monophyletic clade, but we propose elevating R. c. stuhlmanni to a full species.

Intra-specific pelage color variation in a South American small rodent species.

Intra-specific color variation is often underestimated by researchers, and among mammals, intra-specific differences in coloration are poorly documented for most species. The main goal of this study was to apply an objective color measurement methodology to the study of a specific problem: the detection, if any, of patterns of changes in the fur color of specimens of Akodon budini in relation to biological (i.e., sex) and environmental (i.e., season) variables. We hypothesize that coat color will be more homogeneous in males than in females and that coat color will be darker in winter than in summer, the latter being orange. We measured the pelage color on five points over the dorsal surface of 26 A. budini museum specimens using a spectroradiometer and a diffuse illumination cabin. We used Principal Component Analysis to describe the association between the color variables, sex and season, and each of the observations. We then used general linear models of Analysis of Variance to examine relationships between color data, season, and sex. The results clearly confirm the hypothesis related to seasonal coat color change but do not directly confirm the hypothesis related to changes in coat color in relation to sex, and we show the complexity of the studied pattern. In conclusion, undoubtedly, the studied variables should accordingly be considered when studying the coloration of specimens for characterization, identification and discrimination of different taxonomic units based on color.

Climate change induced molting mismatch? Mountain hare abundance reduced by duration of snow cover and predator abundance

AbstractIn northern latitudes, species that have adapted to snow cover by molting and changing pelage color will be particularly vulnerable to climate change, as predation levels may increase due to a mismatch with background coloration. Here, we investigated the synergistic effect of mammalian generalist predators (red fox Vulpes vulpes and pine marten Martes martes) and the duration of snow cover on the abundance of a winter‐adapted species, the mountain hare (Lepus timidus). We analyzed 12 yr of data from 622 snow tracking lines in southeast Norway along a gradient in annual duration of snow‐covered ground. The mountain hare abundance index was positively related to the generalist predator abundance index, probably due to a combined numerical and functional response of the predators. The mountain hare abundance index was negatively associated with a short duration of snow cover, and this effect was stronger in areas with a high predator abundance index. Hence, we demonstrated a causal link between the mountain hare abundance index, predators, and the duration of snow cover. We expect declining mountain hare densities in the future caused by interactive effects of reduced duration of snow‐covered ground, potentially increasing generalist predator densities and the limited ability of mountain hares to adapt to the climate change‐induced molting mismatch.

Why is the giant panda black and white?

Lay Summary We use comparative information on carnivores and bear subspecies to investigate coloration of the giant panda. We find that white fur on the body is for matching white snowy backgrounds, black fur on legs is for camouflage in shade, but that markings on the face are for communication to other pandas or to would-be predators. The giant panda’s extrordinary pelage coloration has several different functions.

A giant among dwarfs: a new species of galago (Primates: Galagidae) from Angola.

Based on vocalization recordings of an unknown galago species, our main objectives were to compare morphology and call structure with known closely-related taxa and describe a new species of galago. We conducted field surveys in three forest habitats along the escarpment region in western Angola (Kumbira Forest, Bimbe Area, and Northern Scarp Forest), and examined galago specimens from museums worldwide. We digitized and analyzed calls using Avisoft SASLab Pro software. We also compared museum specimens from Angola with other Galago and Galagoides specimens, and conducted comparative analyses (ANOVA and between group principle component analysis) based on a set of twelve linear measurements of skulls and teeth. We describe the new species to which we give the name Angolan dwarf galago, Galagoides kumbirensis sp. nov. The new species has a loud and characteristic crescendo call, used by other Galagoides spp. (sensu stricto) in West Africa to attract companions and repel rivals. However, this call shows species-typical differences from its closest relatives. Galagoides kumbirensis sp. nov. is also distinguished by differences in the skull morphology, pelage color and facial markings, as well as a larger body size, similar to that of Galago moholi, which is not known to be sympatric. This discovery points to the importance of Angolan forests as refuges for endemic biodiversity. These forests are under severe threat from overexploitation, and there is an urgent need to establish conservation measures and designate protected areas.

A New Species ofMonodelphis(Didelphimorphia: Didelphidae) from the Brazilian Amazon

ABSTRACT We describe a new species of the didelphid marsupial genus Monodelphis from Brazil, where it appears to be widely distributed in the states of Para, Mato Grosso, Rondonia, and Acre. Monodelphis saci, new species, belongs to the subgenus Mygalodelphys, and analyses of DNA sequence data suggest that it is most closely related to M. handleyi, M. osgoodi, and M. peruviana. Diagnostic morphological traits include pelage coloration, qualitative aspects of craniodental morphology, and a distinctive range of morphometric variation. The new species has sometimes been misidentified in the literature as M. kunsi, a distinct but apparently allopatric taxon. Monodelphis saci occurs sympatrically with M. emiliae, M. glirina, and M. touan in the rainforested lowlands south of the Amazon River.