Tail Hairs Research Articles

Physical, thermal and mechanical properties of horse tail and mane hairs

Purpose This study aims to comparatively reveal the physical, thermal and mechanical properties of horse tail and mane hairs, which have the potential to be used in many areas. Design/methodology/approach Physical properties of horsehairs such as diameter, density, moisture and water absorption were measured. Fourier transform infrared, field emission scanning electron microscopy and amino acid analyzes were applied to the hairs. Thermal stability of horsehair was investigated by thermogravimetric analysis and differential scanning calorimetry analysis. In addition, breaking strength and elongation values of mane and tail hairs were measured. Findings As a result of morphological analysis of horsehair, it was observed that there are usually gaps in the internal structure of horsehair, but the size and continuity of these gaps vary. It has been determined that there is a significant difference between the tenacity values of tail and mane hairs as well as geometric characteristics. In addition, amino acid analysis has shown that the amino acid contents of horse tail and mane hairs are similar and not much different from sheep’s wool. Originality/value Horsehair has been used for various purposes such as clothing, accessories, brushes, upholstery and reinforcement material. To use horsehair in accordance with its application area and performance characteristics, it is necessary to know its physical, thermal and mechanical properties. It is considerable to reveal the similar and different aspects of tail and mane hairs to determine whether they are alternatives to each other. Therefore, revealing the characteristics of tail and mane hairs comparatively constitutes the originality of this study.

Scanning Electron Microscopy of the Inner and Outer Aspects of Tiger Tail Hairs.

Tiger tail hairs, Morse hairs or pili annulati is a nonsyndromic hair shaft disorder, characterized by alternating light and dark bands along the hair shaft. The outer surface and the inner structure of longitudinally cut tiger tail hairs were examined with scanning electron microscopy. Hair specimens of five affected individuals showed small surface undulations with "curtain-like" folding of the hair cuticula (microcanaliculi). In the inner surface cord-like linear structures with serpiginous, tortuous traject were seen, associated with some cavities. These findings suggest that this condition is due to some deficient protein synthesis/arrangement, not only due to cavities in the hair cortex. The term Tiger tail hair is a descriptive clinical term of little scientific rigor. This disorder has been reported mainly as pili annulati; however, rings are not observed. In analogy to pili canaliculi, in which well-formed grooving is observed in the hair surface, we suggest the term pili microcanaliculi to describe this condition, based in the ultrastructural findings.

Method development to characterise elephant tail hairs by LA-ICP-MS to reflect changes in elemental chemistry

This paper evaluated analytical methods used to generate time-series data from elephant tail hairs, which can be used to reflect changing exposure to environmental geochemistry. Elephant tail hairs were analysed by three methods sequentially, each providing data to inform subsequent analysis. Scanning Electron Microscopy (SEM) and X-ray Microanalysis visually showed the structure of the hair, specific structures such as tubules, and the mineral crusting around the edge of the hair, informing targeting of subsequent analysis by Laser Ablation-Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS). LA-ICP-MS generated time-series data which informed sectioning of the tail hairs for subsequent quantitative analysis for potentially toxic elements and micronutrients using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) of dissolved tail hairs. This novel approach to characterise the tail hair enabled time-series analysis to reflect changes in environmental exposure which may result from seasonal or geochemical spatial variation and could inform elephant movement patterns. The seasonal change between wet and dry seasons was reflected down the length of the hair. Correlations were seen between LA-ICP-MS data and ICP-MS data in several elements including Mg, P, Ca, Fe, Na, Mn and U. This study provided time-series data for the analysis of elephant tail hairs by evaluating analytical challenges to obtaining quantitative data, such as improving protocols to ensure removal of extraneous material, determining where to section the tail hairs to best reflect environmental changes/exposure and ensuring representative analyses. A protocol was established to determine mineral status across a 12–18 month time period utilizing single elephant tail hairs.

MtDNA D-loop sequence analysis of Kalang, Krayan, and Thale Noi buffaloes (Bubalus bubalis) in Indonesia and Thailand reveal genetic diversity

Kalang (KBuf), Krayan (KrBuf), and Thale Noi buffaloes (TBuf) are swamp buffalo genetic resources in Indonesia and Thailand. The maternally inherited mitochondrial DNA (mtDNA), particularly D-loop region is an important material for phylogenetic inference and analyzing genetic diversity. Therefore, the objectives of the present study were to evaluate genetic diversity and to reconstruct the phylogenetic tree within buffalo breeds in Kalimantan, Indonesia, and Phatthalung, Thailand using mtDNA D-loop sequences. A total of one hundred forty buffaloes (70 males and 70 females) were observed including 40 buffaloes from North (NK), 40 from East (EK), and 40 from South Kalimantan (SK) provinces Indonesia and 20 from Phatthalung (PT) province, Thailand. DNA samples were isolated from buffalo tail hairs. DNA sequences were manually assembled using BioEdit program with consideration of gaps and ambiguous sequences. The phylogenetic tree of buffalo was generated by PHYLIP software. The observed variables included haplotype diversity, genetic distance, and genetic tree. The 956 bp of amplified mtDNA D-loop fragment presented a total of 24 haplotypes with several mutations that included transitions (293), transversions (60), deletions (15), and insertions (20). The neighbor-joining tree using the Kimura 2 parameter model demonstrated two local buffalo clusters among buffalo from Kalimantan and Thailand with four buffalo relationship patterns observed from buffaloes in Kalimantan Island (KBuf and KrBuf), Indonesia. The Results of the present study demonstrated that the buffaloes sequence analysis revealed relatively high diversity and is a good basis to perform selection and modern buffalo breeding development.

Tracking animal movements using biomarkers in tail hairs: a novel approach for animal geolocating from sulfur isoscapes

BackgroundCurrent animal tracking studies are most often based on the application of external geolocators such as GPS and radio transmitters. While these technologies provide detailed movement data, they are costly to acquire and maintain, which often restricts sample sizes. Furthermore, deploying external geolocators requires physically capturing and recapturing of animals, which poses an additional welfare concern. Natural biomarkers provide an alternative, non-invasive approach for addressing a range of geolocation questions and can, because of relatively low cost, be collected from many individuals thereby broadening the scope for population-wide inference.MethodsWe developed a low-cost, minimally invasive method for distinguishing between local versus non-local movements of cattle using sulfur isotope ratios (δ34S) in cattle tail hair collected in the Greater Serengeti Ecosystem, Tanzania.ResultsWe used a Generalized Additive Model to generate a predicted δ34S isoscape across the study area. This isoscape was constructed using spatial smoothers and underpinned by the positive relationship between δ34S values and lithology. We then established a strong relationship between δ34S from recent sections of cattle tail hair and the δ34S from grasses sampled in the immediate vicinity of an individual’s location, suggesting δ34S in the hair reflects the δ34S in the environment. By combining uncertainty in estimation of the isoscape, with predictions of tail hair δ34S given an animal’s position in the isoscape we estimated the anisotropic distribution of travel distances across the Serengeti ecosystem sufficient to detect movement using sulfur stable isotopes.ConclusionsWhile the focus of our study was on cattle, this approach can be modified to understand movements in other mobile organisms where the sulfur isoscape is sufficiently heterogeneous relative to the spatial scale of animal movements and where tracking with traditional methods is difficult.

Stable isotopic signatures in modern wood bison (Bison bison athabascae) hairs as telltale biomarkers of nutritional stress

Assessing the challenges faced by wildlife populations is key to providing effective management but is problematic when dealing with populations in remote locations. Analyses of the stable carbon and nitrogen isotope composition (expressed as δ13C and δ15N values) of sequentially grown tissues, such as hairs, can be used to track changes in the eco-physiology of organisms. We generated δ13C and δ15N values from sequentially sampled (n = 465) hairs taken from wood bison (Bison bison athabascae Rhoads, 1898) (n = 27). Samples were taken from individuals prior to and after their release from captivity into the lower Innoko–Yukon river area of Alaska in 2015. Twenty months after release, individuals had a distinct seasonal pattern in δ13C values. Hairs from individuals that experienced food scarcity or long-distance movement were sampled as case studies. Nutritional stress in these cases lead to a rise in δ15N values and a decrease in δ13C values. Applications of δ13C and δ15N analyses of bison tail hairs could provide wildlife managers a valuable and minimally invasive tool to better understand bison seasonal metabolic status and determine the historical health and behavior of living and dead individuals.

Creating artificial Rhino Horns from Horse Hair

Demand for rhino horn is driving poaching with devastating effect for the few individuals left of the few species surviving from this once numerous, widespread and cosmopolitan clade of pachyderms. We bundled together tail hairs of the rhino’s ubiquitous near relative, the horse, to be glued together with a bespoke matrix of regenerated silk mimicking the collagenous component of the real horn. This approach allowed us to fabricate composite structures that were confusingly similar to real rhino horn in look, feel and properties. Spectral and thermal FT-IR, DSC and TGA analysis demonstrated the similar chemical composition and thermo-mechanical properties between the natural and the faux horns.

Grazing high and low: Can we detect horse altitudinal mobility using high-resolution isotope (δ13 C and δ15 N values) time series in tail hair? A case study in the Mongolian Altai.

Carbon and nitrogen stable isotope time series performed in continuously growing tissues (hair, tooth enamel) are commonly used to reconstruct the dietary history of modern and ancient animals. Predicting the effects of altitudinal mobility on animal δ13 C and δ15 N values remains difficult as several variables such as temperature, water availability or soil type can contribute to the isotope composition. Modern references adapted to the region of interest are therefore essential. Between June 2015 and July 2018, six free-ranging domestic horses living in the Mongolian Altaï were fitted with GPS collars. Tail hairs were sampled each year, prepared for sequential C and N isotope analysis using EA-IRMS. Isotopic variations were compared with altitudinal mobility, and Generalized Additive Mixed (GAMMs) models were used to model the effect of geographic and environmental factors on δ13 C and δ15 N values. Less than half of the pasture changes were linked with a significant isotopic shift while numerous isotopic shifts did not correspond to any altitudinal mobility. Similar patterns of δ13 C and δ15 N variations were observed between the different horses, despite differences in mobility patterns. We propose that water availability as well as seasonal availability of N2 fixing type plants primarily controlled horse hair δ13 C and δ15 N values, overprinting the influence of altitude. Our study shows that altitudinal mobility is not the main factor that drives the variations in horse tail hair δ13 C and δ15 N values and that seasonal change in the animal dietary preference also plays an important role. It is therefore risky to interpret variations in δ13 C and δ15 N values of animal tissues in terms of altitudinal mobility alone, at least in C3 -dominated environments.

An Arab Chariot Monument at Umm al-Jimāl

ABSTRACTThis article deals with unpublished fragments of sculpture in basalt found at Umm al-Jimāl, a site of a ruined Nabataean-Roman to Byzantine settlement in northern Jordan, six kilometers south of the border with Syria. The sculptures are typical for the southern Syrian volcanic zone of the Hawrān. The site is located at the extreme southern outcrop of this area, today part of The Hashemite Kingdom of Jordan.The fragments are contemporary with a better-preserved corpus of similar sculptures investigated by the authors in the basalt desert of al-Ledjā, ancient Trachon(itis). At Umm al-Jimāl, an analogous chariot group driven by deities can be identified by a wheel block with traces of the tail hairs of animals in harness. The assembled figures in human shape with drapery are parallel to the Sahr al-Ledjā statuary. Taking all extant evidence into account, the authors propose recognizing the sculptural remnants from Umm al-Jimāl as testimony of a strongly Hellenistic-Romanized embellishment of a hitherto little-known Arab-Nabataean sanctuary dating to the first or second century AD. This shrine together with its sculptures had most probably been destroyed by the Palmyrenean Campaign in the later third century AD.

A missense variant in the coil1A domain of the keratin 25 gene is associated with the dominant curly hair coat trait (Crd) in horse

BackgroundCurly horses present a variety of curl phenotypes that are associated with various degrees of curliness of coat, mane, tail and ear hairs. Their origin is still a matter of debate and several genetic hypotheses have been formulated to explain the diversity in phenotype, including the combination of autosomal dominant and recessive alleles. Our purpose was to map the autosomal dominant curly hair locus and identify the causal variant using genome-wide association study (GWAS) and whole-genome sequencing approaches.ResultsA GWAS was performed using a Bayesian sparse linear mixed model, based on 51 curly and 19 straight-haired French and North American horses from 13 paternal families genotyped on the Illumina EquineSNP50 BeadChip. A single strong signal was observed on equine chromosome 11, in a region that encompasses the type I keratin gene cluster. This region was refined by haplotype analysis to a segment including 36 genes, among which are 10 keratin genes (KRT-10, -12, -20, -23, -24, -25, -26, -27, -28, -222). To comprehensively identify candidate causal variants within all these genes, whole-genome sequences were obtained for one heterozygous curly stallion and its straight-haired son. Among the four non-synonymous candidate variants identified and validated in the curly region, only variant g.21891160G>A in the KRT25 gene (KRT25:p.R89H) was in perfect agreement with haplotype status in the whole pedigree. Genetic association was then confirmed by genotyping a larger population consisting of 353 horses. However, five discordant curly horses were observed, which carried neither the variant nor the main haplotype associated with curliness. Sequencing of KRT25 for two discordant horses did not identify any other deleterious variant, which suggests locus rather than allelic heterogeneity for the curly phenotype.ConclusionsWe identified the KRT25:p.R89H variant as responsible for the dominant curly trait, but a second dominant locus may also be involved in the shape of hairs within North American Curly horses.

Manganese, iron and cobalt contents in brown, black and white mane, coat and tail hairs in horses of two locations

Manganese, iron and cobalt contents in brown, black and white mane, coat and tail hairs in horses of two locations

Selenium, copper and zinc contents in brown, black and white mane, coat and tail hairs in horses of two locations

Selenium, copper and zinc contents in brown, black and white mane, coat and tail hairs in horses of two locations

Sequential stable isotope analysis reveals differences in multi-year dietary history of three sympatric equid species in SW Mongolia.

Summary Competition among sympatric wild herbivores is reduced by different physiological, morphological and behavioural traits resulting in different dietary niches. Wild equids are a rather uniform group of large herbivores which have dramatically declined in numbers and range. Correlative evidence suggests that pasture competition with livestock is one of the key factors for this decline, and the situation may be aggravated in areas where different equid species overlap.The Dzungarian Gobi is currently the only place where two wild equid species coexist and share the range with the domesticated form of a third equid species. In the winter‐cold Gobi desert pasture productivity is low, highly seasonal, and wild equids additionally face increasing livestock densities.We used stable isotope chronologies of tail hairs to draw inferences about multi‐year diet seasonality, isotopic dietary niches and physiological adaptations in the Asiatic wild ass (khulan), re‐introduced Przewalski's horse, and domestic horse in the Mongolian part of the Dzungarian Gobi.Our results showed that even in the arid Gobi, both horse species are predominantly grazers, whereas khulan are highly seasonal, switching from being grazers in summer to mixed feeders in winter. The isotopic dietary niches of the two horse species were almost identical, did not vary with season as in khulan and were narrower than in the latter. Higher δ15N values point towards higher water use efficiency in khulan, which may be one reason why they can exploit pastures further away from water. Synthesis and applications. The high degree of isotopic dietary niche overlap in the two horse species in the Mongolian Gobi points towards a high potential for pasture competition during the critical nutritional bottleneck in winter and highlights the need to severely restrict grazing of domestic horses on the range of the Przewalski's horses. The evolutionary more distant khulan are less constrained by water and seem more flexible in their choice of diet or less successful in exploiting grass‐dominated habitats in winter due to human presence. Providing additional water sources could increase the competition between khulan and livestock and should, therefore, only be done following careful consideration.

Re-constructing nutritional history of Serengeti wildebeest from stable isotopes in tail hair: seasonal starvation patterns in an obligate grazer.

RationaleNutritional bottlenecks often limit the abundance of animal populations and alter individual behaviours; however, establishing animal condition over extended periods of time using non‐invasive techniques has been a major limitation in population ecology. We test if the sequential measurement of δ15N values in a continually growing tissue, such as hair, can be used as a natural bio‐logger akin to tree rings or ice cores to provide insights into nutritional stress.MethodsNitrogen stable isotope ratios were measured by continuous‐flow isotope‐ratio mass spectrometry (IRMS) from 20 sequential segments along the tail hairs of 15 migratory wildebeest. Generalized Linear Models were used to test for variation between concurrent segments of hair from the same individual, and to compare the δ15N values of starved and non‐starved animals. Correlations between δ15N values in the hair and periods of above‐average energy demand during the annual cycle were tested using Generalized Additive Mixed Models.ResultsThe time series of nitrogen isotope ratios in the tail hair are comparable between strands from the same individual. The most likely explanation for the pattern of 15N enrichment between individuals is determined by life phase, and especially the energetic demands associated with reproduction. The mean δ15N value of starved animals was greater than that of non‐starved animals, suggesting that higher δ15N values correlate with periods of nutritional stress.ConclusionsHigh δ15N values in the tail hair of wildebeest are correlated with periods of negative energy balance, suggesting they may be used as a reliable indicator of the animal's nutritional history. This technique might be applicable to other obligate grazers. Most importantly, the sequential isotopic analysis of hair offers a continuous record of the chronic condition of wildebeest (effectively converting point data into time series) and allows researchers to establish the animal's nutritional diary.

A protocol to correct for intra- and interspecific variation in tail hair growth to align isotope signatures of segmentally cut tail hair to a common time line.

RationaleIn recent years, segmental stable isotope analysis of hair has been a focus of research in animal dietary ecology and migration. To correctly assign tail hair segments to seasons or even Julian dates, information on tail hair growth rates is a key parameter, but is lacking for most species.MethodsWe (a) reviewed the literature on tail hair growth rates in mammals; b) made own measurements of three captive equid species; (c) measured δ2H, δ13C and δ15N values in sequentially cut tail hairs of three sympatric, free-ranging equids from the Mongolian Gobi, using isotope ratio mass spectrometry (IRMS); and (d) collected environmental background data on seasonal variation by measuring δ2H values in precipitation by IRMS and by compiling pasture productivity measured by remote sensing via the normalized difference vegetation index (NDVI).ResultsTail hair growth rates showed significant inter- and intra-specific variation making temporal alignment problematic. In the Mongolian Gobi, high seasonal variation of δ2H values in precipitation results in winter lows and summer highs of δ2H values of available water sources. In water-dependent equids, this seasonality is reflected in the isotope signatures of sequentially cut tails hairs.ConclusionsIn regions which are subject to strong seasonal patterns we suggest identifying key isotopes which show strong seasonal variation in the environment and can be expected to be reflected in the animal tissue. The known interval between the maxima and minima of these isotope values can then be used to correctly temporally align the segmental stable isotope signature for each individual animal. © 2015 The Authors. Rapid Communications in Mass Spectrometry published by John Wiley & Sons Ltd.

An experimental study investigating the ability of volunteers to identify squirrel species from tail–hair samples

Hair–tubes, collecting nape hairs, are widely used for establishing the presence of red (Sciurus vulgaris) and grey (Sciurus carolinensis) squirrels. However it is time–consuming and prone to identification errors. An alternative is to collect tail hairs from sticky pads on baited poles. However, there is no evidence concerning identification accuracy of tail hairs. This study reports an experiment in which subjects underwent a short training session before identifying hair samples from four species. There was a 96.5% correct identification rate for grey squirrel hairs, and 77.5% for red squirrels, which suggests that tail hairs collection may provide a quick, easy and accurate method of identification for both species.

Stable isotope turnover and variability in tail hairs of captive and free-ranging African elephants (Loxodonta africana) reveal dietary niche differences within populations

Many herbivore species expand their dietary niche breadths by switching from browse-rich diets in dry seasons to grass-rich diets in rainy seasons, in response to phenological changes in plant availability and quality. We analyzed stable isotope series along tail hairs of captive and free-ranging African elephant (Loxodonta africana (Blumenbach, 1797)) to compare patterns of seasonal dietary variability across individuals. Results from elephants translocated from the wild into captivity, where their diets are semicontrolled, revealed tail hair growth rates of ∼0.34 mm/day, on average, and relatively rapid isotope turnover through the transition from wild into captivity. Sampling hairs at 10 mm increments thus archives dietary chronologies at a resolution suitable for tracking diet switches at seasonal, and even subseasonal, scales. Hairs of free-ranging elephants showed extensive carbon isotopic variability within individuals, consistent with seasonal switches between C3-browsing and C4-grazing. Similarly extensive, but asynchronous, shifts in nitrogen isotope ratios were also observed, suggesting an influence of factors other than seasonality. Across individuals, switching patterns differed across habitats, and across age classes, with older, larger animals including increasing amounts of C3browse into their diets. These results demonstrate how stable isotope approaches characterize complex patterns of resource use in wildlife populations.

Do black-furred animals compensate for high solar absorption with smaller hairs? A test with a polymorphic squirrel species

Abstract In polymorphic mammalian species that display multiple color forms, those with dark, or melanic pelage would be prone to overheating, especially if they live in warm climates, because their fur absorbs solar energy at a higher rate. However, experimental studies indicate that certain physical properties of fur of dark individuals appear to prevent, or minimize heat stress, although it is not clear what properties do so. Here, we tested the possibility that black-furred individuals simply have shorter or thinner hair fibers, which would create a lighter (in terms of weight) coat or one that allows greater air flow for evaporative cooling. We examined museum specimens of eastern fox squirrels Sciurus niger, a species native to the United States and one that displays brown, grey or all-black pelage color, and used image analysis procedures to quantify hairs from the dorsal surface and tail. From examination of 43 specimens (19 brown, 9 black and 15 grey), and 1,720 hairs, we found no significant difference in hair lengths across color morphs, but significant differences in hair fiber widths. Black squirrels had thinner body hairs than other forms (7% thinner), but thicker tail hairs (9% thicker) than the others. Given that the dorsal surface would be directly exposed to solar radiation, we interpret this to be an adaptation to prevent heat stress during the day. The thicker tail hairs may be an adaptation for nighttime thermoregulation, since squirrels sleep with their tails wrapped around their bodies. These results add to a growing literature body of the functional significance of mammalian pelage.

Forensic species identification of elephant (Elephantidae) and giraffe (Giraffidae) tail hair using light microscopy

Here we present methods for distinguishing tail hairs of African elephants (Loxodonta africana), Asian elephants (Elephas maximus), and giraffes (Giraffa camelopardalis) from forensic contexts. Such hairs are commonly used to manufacture jewelry artifacts that are often sold illegally in the international wildlife trade. Tail hairs from these three species are easily confused macroscopically, and morphological methods for distinguishing African and Asian tail hairs have not been published. We used cross section analysis and light microscopy to analyze the tail hair morphology of 18 individual African elephants, 18 Asian elephants, and 40 giraffes. We found that cross-sectional shape, pigment placement, and pigment density are useful morphological features for distinguishing the three species. These observations provide wildlife forensic scientists with an important analytical tool for enforcing legislation and international treaties regulating the trade in elephant parts.

Establishing chronologies from isotopic profiles in serially collected animal tissues: An example using tail hairs from African elephants

While the use of stable isotopes in wildlife ecological research is growing rapidly, development of methods to establish time-specific isotope data from continuously growing animal tissues are lacking. Using serially collected tail hairs from wild African elephants ( Loxodonta africana), we develop and compare four techniques to collate temporal isotope chronologies from metabolically inert tissues for which formation/growth overlapped in time. The influence of variation in within hair growth rates and other sources of error in the presented techniques are explored and found to be inconsequential relative to the 5-day tissue sampling interval. Using a floating point regression approach, we find a high degree of correlation between independently derived isotope profiles from the same and different individuals in the study ecosystem. Remotely sensed Normalized Difference Vegetation Index (NDVI) data is compared with the isotope derived diet chronologies from five elephants developed independently. Diet shifts from browse to grass occurring at the onset of the wet season were highly synchronized, while early dry season diets varied across individuals. These methods are applicable across a variety of keratinous tissues and even teeth and, as demonstrated by our results, can be implemented using profiles from different individuals or relating profiles to environmental variation (seasonality). As such, the presented methods allow the establishment of high resolution temporal data on diet, movement, and climatic conditions experienced by an organism in many research settings.