Facial Stripes Research Articles

The role of high-contrast male facial stripes in mitigating female aggression in the jumping spider Plexippus paykulli

The role of high-contrast male facial stripes in mitigating female aggression in the jumping spider Plexippus paykulli

Estimating the density of small mammals using the selfie trap is an effective camera trapping method

Camera trapping to study wildlife allows for data collection, without the need to capture animals. Traditionally, camera traps have been used to target larger terrestrial mammal species, though recently novel methods and adjustments in procedures have meant camera traps can be used to study small mammals. The selfie trap (a camera trapping method) may present robust sampling and ecological study of small mammals. This study aimed to evaluate the selfie trap method in terms of its ability to detect species and estimate population density. To address this aim, standard small mammal live trapping was undertaken, immediately followed by camera trapping using the selfie trap. Both methods were set to target the arboreal sugar glider (Petaurus breviceps) and semi-arboreal brown antechinus (Antechinus stuartii). The more ground-dwelling bush rat (Rattus fuscipes) was also live trapped and recorded on camera. Across four survey areas, the probability of detection for each of the three species was higher for selfie traps than for live trapping. Spatially explicit capture-recapture models showed that selfie traps were superior at estimating density for brown antechinus and sugar gliders, when compared to simulated live trapping data. Hit rates (number of videos per various time intervals) were correlated with abundance. When correlating various hit rate intervals with abundance, the use of 10-min hit rate was best for predicting sugar glider abundance (R2 = 0.94). The abundance of brown antechinus was estimated from selfie traps using a 24-h hit rate as a predictor (R2 = 0.85). For sugar gliders, the selfie trap can replace live trapping as individuals can be identified through their unique facial stripes and natural ear scars, and thus used in capture-recapture analysis. This method may be useful for monitoring the abundance of other small mammal species that can also be individually recognized from photographs.

Cirrhilabruswakanda, a new species of fairy wrasse from mesophotic ecosystems of Zanzibar, Tanzania, Africa (Teleostei, Labridae).

Cirrhilabruswakandasp. nov. is described on the basis of the holotype and four paratypes collected between 50 and 80m depth over low-complexity reef and rubble bottoms at the east coast of Zanzibar, Tanzania, Africa. The new species belongs to a group of fairy wrasses from the western Indian Ocean, sharing a combination of characters that include: short pelvic fins (not or barely reaching anal-fin origin); relatively unmarked dorsal and anal fins; males with a strongly lanceolate caudal fin (except in C.rubrisquamis); both sexes with a pair of prominent facial stripes above and below the orbit; and both sexes with prominent purple scales and osseus elements that persist, and stain purple, respectively, even in preservation. This group of fairy wrasse is part of a larger complex that includes related species from the western Pacific Ocean. In addition to meristic and morphometric comparisons, we also compare mitochondrial DNA sequence data to the aforementioned, putatively related species.

The phylogeny of francolins (Francolinus, Dendroperdix, Peliperdix and Scleroptila) and spurfowls (Pternistis) based on chick plumage (Galliformes: Phasianidae)

BackgroundThis paper describes the chick plumage of spurfowl (Pternistis) and francolin (Francolinus, Dendroperdix, Peliperdix and Scleroptila) chicks, tests its significance for phylogenetic relationships and also explores the patterns of character evolution in the francolin and spurfowl lineages. Previously regarded as monophyletic, the two evolutionarily distant clades are now divided into five genera. Questions considered were whether chick plumage supports the dichotomy between spurfowls and francolins and what role habitat matching plays.MethodsThe study was based mainly on photographs of chick skins from the American Museum of Natural History and the Natural History Museum at Tring. Eight plumage characters were selected for comparative scoring, summarised in a matrix. These characters were subsequently analysed phylogenetically and their evolution was traced on the existing molecular phylogeny using a parsimony approach.ResultsBased on chick plumage the phylogeny of species groups among francolins and spurfowls, was largely unresolved possibly ascribed to a high degree of symplesiomorphy inherent among the Phasianids. This possibly could have resulted in a high degree of polytomy particularly among the spurfowls and francolins. Furthermore, the ancestral state reconstructions revealed high prevalence of symplesiomorphic states and reversals which do not help in the classification of groups. Although the differences are described that separate some African francolins from spurfowls, other francolins (in Asia and Africa) share remarkably similar characteristics with spurfowls. Plain dark dorsal plumage is probably advantageous for avoiding detection by predators in forests, while facial stripes optimise the breaking of body shapes in dense grass cover (as in Scleroptila spp.) and semi-striped faces are advantageous for stationary camouflage under tree and bush cover (as in Pternistis spp.).ConclusionsAlthough symplesiomorphy is a hereditary explanation for downy colours and patterns, the traits relevant for habitat matching are combined in a manner which is determined (adaptation) by natural selection.

Artibeus glaucus(Chiroptera: Phyllostomidae)

Abstract The silvery fruit-eating bat (Artibeus glaucus Thomas, 1893) is a small sized phyllostomid bat with indistinct facial stripes and obscure pale edging on the ears, dark brown pelage with less contrast on the shoulders and venter, and dorsal fur that extends beyond the posterior margin of the uropatagium. It has a narrow distribution associated with intermediate elevations (200–2,000 m) in the Andean Mountains, mainly in Ecuador, Peru, and Bolivia. It has also been found to inhabit lowland areas but not in high numbers. A. glaucus is classified as “Least Concern” by the International Union for Conservation of Nature and Natural Resources.

Facial Patterns are a Conventional Signal of Agonistic Ability in Polistes exclamans Paper Wasps

Some animals minimize the high costs of aggressive conflict by using conventional signals of agonistic ability to assess rivals prior to interacting. Conventional signals are more controversial than other signals of agonistic ability because they lack an inherent physical or physiological link with their bearer’s agonistic ability. Here, we test whether the variable brown facial stripes in Polistes exclamans paper wasps function as a conventional signal. Polistes exclamans were given the option of challenging or avoiding a rival with an experimentally altered facial pattern. Our results show that rival assessment is based on the facial patterns of rivals, as well as an individual’s own size, facial patterns, and nesting strategy. Individuals with larger body size and larger brown facial stripes were more likely to challenge rivals than individuals with smaller body size and smaller brown facial stripes. In addition, large individuals were more likely to challenge rivals with large brown facial stripes than small individuals, while an individual’s own body size did not influence whether or not they challenged rivals with small brown stripes. Individuals who previously nested in multiple queen groups approached rivals more rapidly than individuals who previously nested alone, suggesting that social experience also plays a role in rival assessment. Finally, rivals with small facial stripes were challenged more rapidly than those with large facial stripes. These results demonstrate that P. exclamans facial patterns function as a signal used to minimize the cost of conflict. However, individuals do not make simple decisions based on their rival’s signal alone, as an individual’s own social experience and agonistic abilities also influence rival assessment decisions.

Evolutionary losses of facial stripes in New World pitvipers

Associations between the evolutionary loss or gain of colours and habitat can be informative about how environment drives colour evolution, and provide insight into their functions. Despite a wealth of studies on colours, the function of many colour patches are not well understood. This is especially the case for dark facial markings. Dark facial stripes are common in snakes, including many pitvipers, which possess facial stripes that extend from the eye towards the corner of the mouth. We investigated whether the evolutionary loss or gain of facial stripes in New World pitvipers is associated with activity period and habitat, hoping to shed light on their function. First, we examined whether evolutionary loss or gain of facial stripes is associated with nocturnal or diurnal activity. It has been suggested that facial stripes may protect the venom from ultraviolet radiation, which would be higher in diurnal species. Similarly, snakes in open habitats may experience higher ultraviolet radiation than those in closed habitats. Alternatively, we examined whether evolutionary loss or gain of facial stripes is associated with terrestrial or non-terrestrial habitat use. Studies on similar facial markings in other vertebrates indicated that they have a signalling function. If facial stripes in pitvipers have a signalling function, arboreal or saxicolous habitat use may limit signal effectiveness. Hence, we hypothesized that there may be an association between facial stripe evolution and habitat use. Using combined phylogenies that included almost every New World pitviper species, we tested correlations between facial stripes and ultraviolet exposure (activity period and habitat openness) and habitat use (terrestrial or non-terrestrial) using concentrated-changes tests and Pagel’s correlation tests. Our data did not support the hypothesis that ultraviolet exposure influenced facial stripe evolution. Instead, the evolutionary loss of facial stripes was associated with non-terrestrial habitat use, such as arboreal and saxicolous habitats. In these habitats, we suggest the effectiveness of facial stripes as a signal would be limited, leading to their evolutionary loss. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 104, 923–933. ADDITIONAL KEYWORDS: aposematic warning – rattlesnakes – signals – ultraviolet radiation.

BOLD COLORATION AND THE EVOLUTION OF APOSEMATISM IN TERRESTRIAL CARNIVORES

Several species of terrestrial carnivores (Mammalia: Carnivora) have bold contrasting color patterns that, in some species, apparently signal possession of noxious anal gland secretions, or even physical strength and great ferocity; yet the evolutionary drivers of both placement and patterning of these contrasting pelage colors on the body, and the ecological selection pressures underlying them, have yet to be systematically examined. Here we explore these issues and find not only that both boldly colored and dichromatic species do indeed often use anal gland secretions for defense, but also that such species are stockier, and live in more exposed habitats where other forms of antipredator defense are limited. We also show that white dorsa are found in sprayers that are primarily nocturnal; that horizontal stripes are found in species that have an ability to spray anal secretions accurately; and that facial stripes are found in burrowing species that typically leave only their heads exposed to attack. Our phylogenetic reconstructions suggest that aposematic coloration has evolved more than once in terrestrial carnivores. We finish by outlining five evolutionary routes for patterns of pelage coloration in this taxon.

The Structure and Function of Yoruba Facial Scarification

Among the Yoruba of southwestern Nigeria, one commonly encounters people with different patterns of facial stripes produced by scarification. It has long been observed that such stripes are labels of clan identification among the Yoruba. This article considers facial stripes from a structural viewpoint, and shows that the attested patterns are rooted in Yoruba number symbolism.

3D Face Recognition Using Isogeodesic Stripes

In this paper, we present a novel approach to 3D face matching that shows high effectiveness in distinguishing facial differences between distinct individuals from differences induced by nonneutral expressions within the same individual. The approach takes into account geometrical information of the 3D face and encodes the relevant information into a compact representation in the form of a graph. Nodes of the graph represent equal width isogeodesic facial stripes. Arcs between pairs of nodes are labeled with descriptors, referred to as 3D Weighted Walkthroughs (3DWWs), that capture the mutual relative spatial displacement between all the pairs of points of the corresponding stripes. Face partitioning into isogeodesic stripes and 3DWWs together provide an approximate representation of local morphology of faces that exhibits smooth variations for changes induced by facial expressions. The graph-based representation permits very efficient matching for face recognition and is also suited to being employed for face identification in very large data sets with the support of appropriate index structures. The method obtained the best ranking at the SHREC 2008 contest for 3D face recognition. We present an extensive comparative evaluation of the performance with the FRGC v2.0 data set and the SHREC08 data set.

Insights into Egyptian Horus Falcon Imagery by Way of Real Falcons and Horus Falcon Influence in the Aegean in the Middle Bronze Age: Part I

The falcon is the most frequently represented bird in Egyptian art. The discovery that falcons were depicted more often than realized in Aegean art, during the author’s studies of Aegean faunal iconography, prompted this article which delves into their natural history as a way to understand the falcon gods of Egypt as well as Egyptian and Aegean falcon depictions. This study found that in both cultures the traits of the depicted falcons center around the Peregrine (Falco peregrinus) and Common Kestrel (Falco tinnunculus ) with some Lanner (Falco biarmicus) head traits. The black malar facial stripe, hooked beak, and tomial ‘tooth’ of falcons characterize all Egyptian falcon depictions. In ancient Egypt the falcon was revered and it appears to hold a special place in Egyptian iconography with everyday images of falcon species not being present.

Chiroderma Doriae (Chiroptera: Phyllostomidae)

Chiroderma doriae O. Thomas, 1891 is a phyllostomid commonly called the Brazilian big-eyed bat. A brown bat with striking facial and dorsal stripes, it is the 2nd largest of the 5 species in the genus Chiroderma. It is endemic to southeastern Brazil with a single record from bordering Paraguay. C. doriae occurs in Atlantic Rain Forest, as well as in a variety of primary and secondary forests and even occasionally in urban parklands. It apparently specializes on wild figs. C. doriae is classified as vulnerable. DOI: 10.1644/816.1.

Parallel evolution of facial stripe patterns in the Neolamprologus brichardi/pulcher species complex endemic to Lake Tanganyika

Colour pattern diversity can be due to random processes or to natural or sexual selection. Consequently, similarities in colour patterns are not always correlated with common ancestry, but may result from convergent evolution under shared selection pressures or drift. Neolamprologus brichardi and Neolamprologus pulcher have been described as two distinct species based on differences in the arrangement of two dark bars on the operculum. Our study uses DNA sequences of the mitochondrial control region to show that relatedness of haplotypes disagrees with species assignment based on head colour pattern. This suggests repeated parallel evolution of particular stripe patterns. The complete lack of shared haplotypes between populations of the same or different phenotypes reflects strong philopatric behaviour, possibly induced by the cooperative breeding mode in which offspring remain in their natal territory and serve as helpers until they disperse to nearby territories or take over a breeding position. Concordant phylogeographic patterns between N. brichardi/N. pulcher populations and other rock-dwelling cichlids suggest that the same colonization routes have been taken by sympatric species and that these routes were affected by lake level fluctuations in the past.

Distribuição geográfica e análise morfológica de Artibeus lituratus Olfers e de Artibeus fimbriatus Gray (Chiroptera, Phyllostomidae) no Rio Grande do Sul, Brasil

A study has been made on the geographical distribution and comparative external and cranial morphological analysis of Artibeus lituratus Olfers, 1818 and Artibeus fimbriatus Gray, 1838 (Chiroptera, Phyllostomidae) in the state of Rio Grande do Sul, Brazil. A. lituratus and A. fimbriatus were found to be sympatric in the state north to the Planicie Costeira, in the Depressao Central, in the hillsides of Serra Geral, and in the northern region of the state, areas previously covered by forests. The southernmost point for Artibeus Leach, 1821 distribution is 30o South, and A. lituratus and A. fimbriatus are the two species found more to the south. The two species studied do not show sexual dimorphism as to external characteristics. Cranial measurements revealed significant differences between males and females of A. lituratus in mandible length, which was significantly larger in females(p<5%), and between males and females of A. fimbriatus, in the length of the set of lower teeth and in the external width between the cingula of canine teeth, which were significantly larger in males (p<5%). No further morphological cranial differences were found between genders of both species. A. lituratus and A. fimbriatus can be externally distinguished by size, for A. lituratus is larger than A. fimbriatus as concerns all external dimensions analysed except for the tibia length (p<5%). The two species can also be differentiated by pelage colour, hair length, and facial stripes appearance. In the skull, a number of differences were found in rostrum format, in the developmental degree of supraorbital and post-orbital crests and pre-orbital and post-orbital processes, and in several cranial dimensions analysed.

Cladistic Reappraisal of Neotropical Stenodermatine Bat Phylogeny

Abstract—Several phylogenies have been proposed for neotropical stenodermatine fruit-eating bats (Phyllostomidae), based on detention, external morphology, osteology and chromosomes. However, these previous analyses did not incorporate fully the idea that relationships should be identified based solely on shared derived characteristics. A critique of past methodology and results, and an alternative phylogeny using a morphological data set supplemented with karyotypic information, is presented. In my analysis, there appear two main lineages. The eight genera of white-shouldered bats form a monophyletic clade based on three synapomorphies (white patch of fur on shoulders, lack of a palatial extension with varying degrees of emargination and modified upper incisors); previous work suggested a paraphyletic relationship for this group. Furthermore, the monophyly of the four genera endemic to the Antilles is supported by two synapomorphies, suggesting a common origin as opposed to a multiple invasion for these genera. The appearance of the derived 2n = 30 and FN = 56 standard karyotype suggests that the morphologically distinct Sturnira forms the sister taxon to the remaining genera which are united by the synapomorphy of white facial stripes. This supports the inclusion of Sturnira within the stendodermatines and not in its own monotypic higher-level taxon. My results do not refute the traditional systematic view of Artibeus (including Dermanura, Koopmania and Enchisthenes) being monophyletic, and supports Mesophylla and Vampyressa being distinct non-sister genera.

CLADISTIC REAPPRAISAL OF NEOTROPICAL STENODERMATINE BAT PHYLOGENY.

Abstract- Several phylogenies have been proposed for neotropical stenodermatine fruit-eating bats (Phyllostomidae), based on detention, external morphology, osteology and chromosomes. However, these previous analyses did not incorporate fully the idea that relationships should be identified based solely on shared derived characteristics. A critique of past methodology and results, and an alternative phylogeny using a morphological data set supplemented with karyotypic information, is presented. In my analysis, there appear two main lineages. The eight genera of white-shouldered bats form a monophyletic clade based on three synapomorphies (white patch of fur on shoulders, lack of a palatial extension with varying degrees of emargination and modified upper incisors); previous work suggested a paraphyletic relationship for this group. Furthermore, the monophyly of the four genera endemic to the Antilles is supported by two synapomorphies, suggesting a common origin as opposed to a multiple invasion for these genera. The appearance of the derived 2n = 30 and FN = 56 standard karyotype suggests that the morphologically distinct Sturnira forms the sister taxon to the remaining genera which are united by the synapomorphy of white facial stripes. This supports the inclusion of Sturnira within the stendodermatines and not in its own monotypic higher-level taxon. My results do not refute the traditional systematic view of Artibeus (including Dermanura, Koopmania and Enchisthenes) being monophyletic, and supports Mesophylla and Vampyressa being distinct non-sister genera.

Control of a teleost social signal. I. Neural basis for differential expression of a color pattern.

Territorial male Haplochromis burtoni (Teleostei; Cichlidae) have a dark facial stripe, the 'eyebar', which can appear and disappear within seconds, independently of other coloration patterns. It is used to signal territory ownership and aggressive intent. Some males, called 'barless', have functional melanophores in the eyebar region but never display this pattern, because melanin in eyebar pigment cells is never dispersed. The eyebar melanophores are controlled by a specialized branch of the maxillary nerve. Lesioning the 'eyebar nerve' resulted in immediate melanin dispersion and consequent darkening of the eyebar pattern, and it abolished the normal paling response in all behavioral situations. Nerve lesion produced similar results in both barred and barless males, except that the coloration of the denervated eyebar in barless males was more similar to camouflage markings than to the conspicuous black eyebar used as a social signal. Electrical stimulation of the maxillary nerve produced melanin aggregation. Photoelectric recordings of this paling response revealed no differences between barred and barless males, or between the eyebar and other facial chromatophores that do not function as visual displays. Thus, the difference in the physiological state of eyebar melanophores in intact barred and barless males cannot be explained by differences in peripheral nerve anatomy or physiology.

Control of a teleost social signal

A prominent dark facial stripe, the 'eyebar', is an important component of the reproductive coloration and dominance displays of 'barred' territorial male Haplochromis burtoni (Teleostei; Cichlidae). 'Barless' territorial males are identical to barred, behaviorally and morphologically, except they completely lack an eyebar during agonistic encounters with conspecifics. Both anatomical and physiological differences characterize eyebar pigment cells of barred and barless males. Melanophores and iridophores, which form a single structural and functional unit in the eyebar, contain less pigment in barless males. Physiologically, eyebar melanophores are tonically expanded in barred males, contracted in barless males. This physiological difference is correlated with a difference in the alpha adrenoceptor-mediated aggregation response of the cells in vitro: eyebar melanophores of barless males are significantly more responsive to physiological concentrations of the sympathetic neurotransmitter norepinephrine than those of barred males, and this intermorph difference appears to be unique to the eyebar color pattern. Physiological and morphological characteristics of eyebar pigment cells are functionally related. When barless males first begin to use the eyebar as a social display, the physiological state of melanophores changes from aggregation to dispersion. In subsequent weeks, additional pigment develops, which enhances conspicuousness of the display.

A new species of rock wallaby, Petrogale persephone (Marsupialia: Macropodidae), from Proserpine, central Queensland.

A new species of rock wallaby, Petrogale persephone, is described from Proserpine, central Queensland. It is distinguished from all known species of rock wallabies by the following combination of characters: absence of distinctive pelage markings except the dark axillary patch and light facial stripe ; ears uniform brownish orange; dorsal surface of body uniformly brown or light platinum; large premolar; ectotympanic ring incomplete or nearly so, not fused to posterior end of zygomatic arch (squamosal); small median pterygoid process arising from lingual flank of pterygoid while lateral pterygoid process is low flattened remnant arising from ventral end of pterygoid next to palatine. The new species appears to be rare and may be endangered as it is known from only two localities near Proserpine where it may be sympatric with Petrogale inornata Gould, 1842.

Review Of The Genus Uroderma (Chiroptera)

The genus Uroderma (order Chiroptera, family Phyllostomatidae) is reviewed. Two species are recognized, both occupying a range from Bolivia and Brazil northward to the Isthmus of Tehuantepec in Mexico. Uroderma bilo-batum Peters, described in 1866, is divided into five geographic races as follows: U. b. bilobatum Peters in eastern Bolivia, Brazil, the Guianas, and most of Venezuela; U. b. thomasi Andersen in western Bolivia, Peru, and Ecuador; U. b. trinitatum, described as new, from the island of Trinidad; U. b. convexum Lyon in western Venezuela, Colombia, most of Panama, and the Pacific versant of Middle America to Oaxaca; U. b. molaris, described as new, in the Atlantic versant of Middle America from western Panama to Veracruz, Mexico. The second species of Uroderma, which is described as new, occurs sympatrically with U. bilobatum. It differs in having a deep, heavy rostrum, a broad, shield-shaped mesethmoid, facial stripes faint or completely lacking, and in lacking an edging of white on the ears.