Three-dimensional modelling and morphometric analysis of skull of badger (Meles meles) with computed tomography images.

BACKGROUND: Morphometric measurements help to understand the skull morphology in different animal species, detect skull deformations and figure out their causes. OBJECTIVES: The aim of this study is to make a three-dimensional (3D) modelling of the badger skull using computed tomography, to show its anatomical structures and to reveal the morphometric measurement values. METHODS: Skull measurements were carried out using a digital calliper at 27 measurement points based on metric measurement points. After the scanned images were stored in Digital Imaging and Communications in Medicine format, they were transferred to MIMICS 20.1 (The Materialize Group) programme and 3D models the skulls were created. The surface area and volume values of the skulls were calculated on these models. RESULTS: The volume and surface area parameters were expressed as mean ± SE. Four different indices were calculated using osteometric measurements. Statistical analyses were made by determining the mean value and standard deviation of the examined properties and the correlation coefficients among these properties. In the metric measurement points taken as a basis, the longest measurement in the skulls was the total length and its mean value was 124.60 ± 0.64 mm. The shortest measurement was the breadth dorsal to the external auditory meatus, and its mean value was 6.75 ± 0.24 mm. CONCLUSIONS: Consequently, statistical differences in the craniometric values of badgers' skulls were determined by using CT and 3D modelling software. In addition, it was concluded that the badger skull can be easily distinguished from other carnivore species by carrying out morphometric measurements.

Effects of weather and social factors on hormone levels in the European badger (Meles meles).

Animals in the wild continually experience changes in environmental and social conditions, which they respond to with behavioural, physiological and morphological adaptations related to individual phenotypic quality. During unfavourable environmental conditions, reproduction can be traded-off against self-maintenance, mediated through changes in reproductive hormone levels. Using the European badger (Meles meles) as a model species, we examine how testosterone in males and oestrogens in females respond to marked deviations in weather from the long-term mean (rainfall and temperature, where badger earthworm food supply is weather dependent), and to social factors (number of adult males and females per social group and total adults in the population), in relation to age, weight and head-body length. Across seasons, testosterone levels correlated postively with body weight and rainfall variability, whereas oestrone correlated positively with population density, but negatively with temperature variability. Restricting analyses to the mating season (spring), heavier males had higher testosterone levels and longer females had higher oestradiol levels. Spring oestrone levels were lower when temperatures were above normal. That we see these effects for this generally adaptive species with a broad bioclimatic niche serves to highlight that climatic effects (especially with the threat of anthropogenic climate change) on reproductive physiology warrant careful attention in a conservation context.

How does bone microanatomy and musculature covary? An investigation in the forelimb of two species of martens (Martes foina, Martes martes).

The long bones and associated musculature play a prominent role in the support and movement of the body and are expected to reflect the associated mechanical demands. But in addition to the functional response to adaptive changes, the conjoined effects of phylogenetic, structural and developmental constraints also shape the animal's body. In order to minimise the effect of the aforementioned constraints and to reveal the biomechanical adaptations in the musculoskeletal system to locomotor mode, we here study the forelimb of two closely related martens: the arboreal pine marten (Martes martes) and the more terrestrial stone marten (Martes foina), focusing on their forelimb muscle anatomy and long bone microanatomy; and, especially, on their covariation. To do so, we quantified muscle data and bone microanatomical parameters and created 3D and 2D maps of the cortical thickness distribution for the three long bones of the forelimb. We then analysed the covariation of muscle and bone data, both qualitatively and quantitatively. Our results reveal that species-specific muscular adaptations are not clearly reflected in the microanatomy of the bones. Yet, we observe a global thickening of the bone cortex in the radius and ulna of the more arboreal pine marten, as well a stronger flexor muscle inserting on its elbow. We attribute these differences to variation in their locomotor modes. Analyses of our 2D maps revealed a shift of cortical thickness distribution pattern linked to ontogeny, rather than species-specific patterns. We found that although intraspecific variation is not negligible, species distinction was possible when taking muscular and bone microanatomical data into consideration. Results of our covariation analyses suggest that the muscle-bone correlation is linked to ontogeny rather than to muscular strength at zones of insertion. Indeed, if we find a correlation between cortical thickness distribution and the strength of some muscles in the humerus, that is not the case for the others and in the radius and ulna. Cortical thickness distribution appears rather linked to bone contact zones and ligament insertions in the radius and ulna, and to some extent in the humerus. We conclude that inference on muscle from bone microanatomy is possible only for certain muscles in the humerus.

Appendicular skeletal morphology of North American Martes reflect independent modes of evolution in conjunction with Pleistocene glacial cycles.

Pleistocene glacial cycles are thought to have driven ecological niche shifts, including novel niche formation. North American pine martens, Martes americana and M. caurina, are exemplar taxa thought to have diverged molecularly and morphologically during Pleistocene glaciation. Previous research found correlations between Martes limb morphology with biome and climate, suggesting that appendicular evolution may have occurred via adaptation to selective pressures imposed by novel and shifting habitats. Such variation can also be achieved through non-adaptive means such as genetic drift. Here, we evaluate whether regional genetic differences reflect limb morphology differences among populations of M. americana and M. caurina by analyzing evolutionary tempo and mode of six limb elements. Our comparative phylogenetic models indicate that genetic structure predicts limb shape better than size. Marten limb size has low phylogenetic signal, and the best supported model of evolution is punctuational (kappa), with morphological and genetic divergence occurring simultaneously. Disparity through time analysis suggests that the tempo of limb evolution in Martes tracks Pleistocene glacial cycles, such that limb size may be responding to shifting climates rather than population genetic structure. Contrarily, we find that limb shape is strongly tied to genetic relationships, with high phylogenetic signal and a lambda mode of evolution. Overall, this pattern of limb size and shape variation may be the result of geographic isolation during Pleistocene glacial advance, while declines in disparity suggest hybridization during interglacial periods. Future inclusion of extinct populations of Martes, which were more morphologically and ecologically diverse, may further clarify Martes phenotypic evolution.

Sex-specific ontogenetic patterns of cranial morphology, theoretical bite force, and underlying jaw musculature in fishers and American martens.

The carnivoran cranium undergoes tremendous growth in size and development of shape to process prey as adults and, importantly, these ontogenetic processes can also differ between the sexes. How these ontogenetic changes in morphology actually relate to the underlying jaw musculature and overall bite performance has rarely been investigated. In this study, I examined sex-specific ontogenetic changes in cranial morphology, jaw adductor muscles, and theoretical bite force between subadults and adults in the fisher (Pekania pennanti) and American marten (Martes americana). I found evidence that cranial size alone does not completely explain ontogenetic increases in bite forces as found in other mammalian species. Instead, cranial shape development also drives ontogenetic increases in relative bite force by broadening the zygomatic arches and enlargement of the sagittal crest, both of which enable relatively larger jaw adductor muscles to attach. In contrast, examination of sexual dimorphism within each age-class revealed that cranial shape dimorphism did not translate to dimorphism in either size-corrected bite forces or size-corrected physiological cross-sectional area of the jaw adductor muscles. These results reveal that morphological size and shape variation can have different influences on bite performance depending on the level of intraspecific variation that is examined (i.e. ontogenetic versus sexual dimorphism).

Papillary architecture in the tayra tongue.

The tayra (Eira barbara) is a mammal belonging to the Mustelidae family that occurs in all Brazilian biomes. The present work aimed to describe the morphology of the tongue of these specimens highlighting their structures and particularities that will serve as a subsidy to elucidate the anatomy of the same and for comparative studies among other species of domestic and wild animals. Five adult male specimens of E. barbara were studied, which were fixed using 10% aqueous formaldehyde solution. The tongue was removed by opening the oral cavity and separating the maxillary/mandible bone complex. Being in possession of the material, photodocumentations and collection of the fragments were made for the proper preparation of histological slides and Scanning Electron Microscopy (SEM). The lingual papillae found in tayra were mechanical: filiform and conical; and gustative: fungiform and circumvallated. Histologically, the papillae are constituted by keratinized stratified epithelium and in the innermost region, it was composed of tissue connective dense unshaped followed by a layer of muscle bundles of skeletal striated. In the region of the root of the tongue of E. barbara, there were a set of small mixed salivary glands (serous and mucous) and the punctual presence of gustatory corpuscles at the level of epithelium. The morphological description of the E. barbara tongue revealed similarity to that described in literature for other domestic and wild mammals. However, the particularity of the absence of foliate papilla and the quantitative of four papillae circumvallate in the region of the root of the tongue of this species.

Greater Hog Badger Arctonyx collaris (Mustelidae, Carnivora) from the Pleistocene of Vietnam (Lang Trang Cave).

The dental remains of a large badger collected in 2020 from the Pleistocene deposits of the Lang Trang karstic cave in northern Vietnam are described. The molars М1 and М1 exhibit the features that are characteristic of Arctonyx collaris Cuvier, 1825. At the same time, the length of M1 of the Lang Trang form exceeds that of modern greater hog badgers. Based on the size and structure of the teeth, it can be assigned to the subspecies A. c. rostratus Matthew et Granger, 1923 known from the Pleistocene of China and Southeast Asia.

First record of the ferret-badger Melogale cucphuongensis Nadler et al., 2011 (Carnivora: Mustelidae), with description of a new subspecies, in southeastern China.

The ferret-badger Melogale cucphuongensis was first described from Cuc Phuong National Park in Vietnam, with no subsequent reports in later years. During our surveys of the Wuyishan Mountains of Fujian Province in southeastern China during May 2018, a Melogale specimen was identified. Analysis based on pelage and skull characteristics as well as molecular data indicated it to be a new subspecies, which we nominated as Melogale cucphuongensis guadunensis subsp. nov. This is the first record of the species in China. Therefore, this research not only expands the distribution range of the species beyond Vietnam, but also indicates that geographic variation of the species should have been proceeding in southeastern China.

Extrinsic factors affecting cub development contribute to sexual size dimorphism in the European badger (Meles meles).

Sexual size dimorphism (SSD) is common among mammals, with males typically being larger than females, as a product of sex-specific differences in growth rate and growth duration. The Musteloidea, however, exhibit a hypo-allometric reduction in SSD with increasing body size (contrary to Rensch's rule). A variety of extrinsic factors can affect juvenile growth rates and end body size, where one sex may demonstrate greater vulnerability than the other towards a specific factor, moderating patterns and degrees of SSD. Here, we analyse how male and female European badgers (Meles meles) differ in their somatic growth patterns. We compare the sex-specific growth curves across a range of somatic parameters and investigate what extrinsic (social and environmental) factors affect cub growth rates during the first 2 years of life leading to their sexual-dimorphic adult sizes. We found that average male final size of all measurements was significantly larger than those of females. Although male and female weanling cubs had similar body sizes, growth curves diverged significantly from ca. 11 months onwards due to continuous rapid growth of males versus slowing female growth. Consequently, females always concluded growth earlier than did males. In both sexes, extremities ceased to grow at an earlier age than did body length and zygomatic arch width. All badger cubs were impacted by their social environment as well as by weather conditions; however, male cubs were more sensitive to social factors, remaining smaller in social groups with more adult males present, whereas female final size was predominantly affected by weather and associated food availability. We discuss how extrinsic parameters can moderate patterns of SSD in the context of the differential equilibrium model.

The Late Pleistocene European badger Meles meles from Grotta Laceduzza (Brindisi, Apulia, Southern Italy): the analysis of the morphological and biometric variability.

In the last decades, many studies have focused on the description of fossil badger materials from Eurasia and several evolutionary hypotheses have been proposed. Nevertheless, the debate on taxonomy of the Late Villafranchian-Aurelian European badgers is still far from being solved and several species/subspecies were established over time. Herein, we described for the first time the craniodental and postcranial remains of Meles meles from Grotta Laceduzza (Apulia, Southern Italy), representing the largest sample of this taxon in the European Pleistocene record. Morphological and morphometric comparisons with fossils coming from the European Pleistocene sites were carried out; morphometric data were also compared with those of several extant populations of the European badger. The results of this work suggest that the badger fossil remains from the Mediterranean region can be considered as an ecomorphotype of this highly polymorphic species, showing a great morphological and morphometric variability throughout its wide geographical range. This variability is mainly expressed in some craniodental features and body size and could reflect local ecological adaptations, also linked to glacial/interglacial cycles.

Heterochrony of puberty in the European badger (Meles meles) can be explained by growth rate and group-size: Evidence for two endocrinological phenotypes.

Puberty is a key stage in mammalian ontogeny, involving endocrinological, physiological and behavioural changes, moderated by intrinsic and extrinsic factors. Thus, not all individuals within one population achieve sexual maturity simultaneously. Here, using the European badger (Meles meles) as a model, we describe male testosterone and female oestrone profiles (using Enzyme-immunoassays) from first capture (3 months, post-weaning) until 28 months (attaining sexual maturity and final body size), along with metrics of somatic growth, scent gland development and maturation of external reproductive organs as well as intra-specific competition. In both sexes, endocrinological puberty commenced at ca. 11 months. Thereafter, cub hormone levels followed adult seasonal hormone patterns but at lower levels, with the majority of cubs reaching sexual maturity during their second mating season (22-28 months). Interestingly, there was evidence for two endocrinological phenotypes among male cubs (less evident in females), with early developers reaching sexual maturity at 11 months (first mating season) and late developers reaching sexual maturity at 22-26 months (second mating season). Early developers also attained a greater proportion of their ultimate adult size by 11 months, exhibiting faster growth rates than late developers (despite having similar adult size). Male cubs born into larger social groups tended to follow the late developer phenotype. Our results support the hypothesis that a minimum body size is required to reach sexual maturity, which may be achieved at different ages, even within a single population, where early maturity can confer individual fitness advantages and enhance population growth rate.

Shared extremes by ectotherms and endotherms: Body elongation in mustelids is associated with small size and reduced limbs.

An elongate body with reduced or absent limbs has evolved independently in many ectothermic vertebrate lineages. While much effort has been spent examining the morphological pathways to elongation in these clades, quantitative investigations into the evolution of elongation in endothermic clades are lacking. We quantified body shape in 61 musteloid mammals (red panda, skunks, raccoons, and weasels) using the head-body elongation ratio. We also examined the morphological changes that may underlie the evolution toward more extreme body plans. We found that a mustelid clade comprised of the subfamilies Helictidinae, Guloninae, Ictonychinae, Mustelinae, and Lutrinae exhibited an evolutionary transition toward more elongate bodies. Furthermore, we discovered that elongation of the body is associated with the evolution of other key traits such as a reduction in body size and a reduction in forelimb length but not hindlimb length. This relationship between body elongation and forelimb length has not previously been quantitatively established for mammals but is consistent with trends exhibited by ectothermic vertebrates and suggests a common pattern of trait covariance associated with body shape evolution. This study provides the framework for documenting body shapes across a wider range of mammalian clades to better understand the morphological changes influencing shape disparity across all vertebrates.

Morphological diversification of biomechanical traits: mustelid locomotor specializations and the macroevolution of long bone cross-sectional morphology.

BACKGROUND: Morphological diversity of limb bone lengths, diameters, and proportions in mammals is known to vary strongly with locomotor habit. It remains less well known how different locomotor habits are correlated with cross-sectional traits of the limb skeleton, such as cross-sectional area (CSA), second moments of area (SMA), and section modulus (MOD) and whether these traits have evolved adaptively. CSA and SMA represent the bone's resistance to axial compression and bending, respectively, whereas MOD represents bone structural strength related to shape. Sampling 28 species of mustelids, a carnivoran lineage with diverse locomotor habits, we tested for differences in humeral, radial, and ulnar cross-sectional traits among specialists for climbing, digging, and swimming, in addition to generalists. Given that the limbs of digging specialists function in the dense substance of soil, and that swimming specialists need to counteract buoyancy, we predicted that these mustelids with these specializations should have the greatest values of cross-sectional traits. RESULTS: We analyzed cross-sectional traits (calculated via µCT scanning and rendered dimensionless) in 5% increments along a bone's length and found significant differences among locomotor habits, though differences in ulnar cross-sectional traits were fewer than those for the humerus and radius. Swimming specialists had the greatest values of cross-sectional traits, followed by digging specialists. Climbing specialists had the lowest values of cross-sectional traits. However, phylogenetic affinity underlies these results. Fitting models of trait evolution to CSA and SMA revealed that a multi-rate Brownian motion model and a multi-optima Ornstein-Uhlenbeck model are the best-fitting models of evolution for these traits. However, inspection of α-values uncovered that many of the OU models did not differ from a Brownian motion model. CONCLUSIONS: Within Mustelidae, differences in limb function and locomotor habit influence cross-sectional traits in ways that produce patterns that may diverge from adaptive patterns exhibited by external traits (e.g., bone lengths) of the mammalian limb skeleton. These results suggest that not all the traits of a single organ evolve under a single evolutionary process and that models of trait evolution should be fit to a range of traits for a better understanding of the evolution of the mammalian locomotor system.

The Results of Sable (Martes zibellina) Reintroduction Demonstrate the Founder Effect.

The relative abundance of intrapopulation groups with different parameters of skull size, coat color, and expression of an epigenetic cranial trait was compared in autochthonous, reintroduced, and donor populations of sable. Recovery of the species resources and broad variability of the phenotypic trait complex in the newly fomned populations were observed. A large proportion of the animals had the phenotype that included large size, dark coat color, and pronounced expression of a specific phene trait (foramen in the condylar fossa) and was not characteristic of the neighboring autochthonous populations. It is reasonable to attribute the presence of individuals with an unusual morphology in the newly formed populations of animals to a manifestation of the founder principle, because the effect of this principle was promoted by spatial isolation of the primary foci of translocated animals.

Effects of diet on cranial morphology and biting ability in musteloid mammals.

Size and shape are often considered important variables that lead to variation in performance. In studies of feeding, size-corrected metrics of the skull are often used as proxies of biting performance; however, few studies have examined the relationship between cranial shape in its entirety and estimated bite force across species and how dietary ecologies may affect these variables differently. Here, we used geometric morphometric and phylogenetic comparative approaches to examine relationships between cranial morphology and estimated bite force in the carnivoran clade Musteloidea. We found a strong relationship between cranial size and estimated bite force but did not find a significant relationship between cranial shape and size-corrected estimated bite force. Many-to-one mapping of form to function may explain this pattern because a variety of evolutionary shape changes rather than a single shape change may have contributed to an increase in relative biting ability. We also found that dietary ecologies influenced cranial shape evolution but did not influence cranial size nor size-corrected bite force evolution. Although musteloids with different diets exhibit variation in cranial shapes, they have similar estimated bite forces suggesting that other feeding performance metrics and potentially nonfeeding traits are also important contributors to cranial evolution. We postulate that axial and appendicular adaptations and the interesting feeding behaviours reported for species within this group also facilitate different dietary ecologies between species. Future work integrating cranial, axial and appendicular form and function with behavioural observations will reveal further insights into the evolution of dietary ecologies and other ecological variables.

First Finding of a Representative of Giant Mustelids of the Genus Eomellivora (Carnivora, Mustelidae) in Russia (Tuva, Upper Miocene).

In the late Miocene deposits in the Taralik-Cher locality (Tuva Republic), fossil remains of a giant mustelid of the genus Eomellivora Zdansky, 1924 have been found. This finding is the first reliable evidence of the Eomellivora inhabiting the modern Russia. Teeth of the Eomelliovra from Taralik-Cher are similar in size to those of E. wimani and E. piveteaui from the late Miocene in Eurasia. The morphology of teeth of the material from Tuva is most similar to that of E. ursogulo; therefore, it is considered a small form of Eomellivora ursogulo. The described finding expands the understanding of diversity, variability, and distribution of representatives of the genus Eomellivora in Asia during the late Miocene.

Carnivory maintains cranial dimorphism between males and females: Evidence for niche divergence in extant Musteloidea.

The evolution and maintenance of sexual dimorphism has long been attributed to sexual selection. Niche divergence, however, serves as an alternative but rarely tested selective pressure also hypothesized to drive phenotypic disparity between males and females. We reconstructed ancestral social systems and diet and used Ornstein-Uhlenbeck (OU) modeling approaches to test whether niche divergence is stronger than sexual selection in driving the evolution of sexual dimorphism in cranial size and bite force across extant Musteloidea. We found that multipeak OU models favored different dietary regimes over social behavior and that the greatest degree of cranial size and bite force dimorphism were found in terrestrial carnivores. Because competition for terrestrial vertebrate prey is greater than other dietary groups, increased cranial size and bite force dimorphism reduces dietary competition between the sexes. In contrast, neither dietary regime nor social system influenced the evolution of sexual dimorphism in cranial shape. Furthermore, we found that the evolution of sexual dimorphism in bite force is influenced by the evolution of sexual dimorphism in cranial size rather than cranial shape. Overall, our results highlight niche divergence as an important mechanism that maintains the evolution of sexual dimorphism in musteloids.

Anatomical Basis of Differences in Locomotor Behavior in Martens: A Comparison of the Forelimb Musculature Between Two Sympatric Species of Martes.

Arboreal locomotion imposes selective pressures that may affect the evolution of the locomotor apparatus. The limbs have to be mobile to reach across discontinuities, yet at the same time need to be forceful to move against gravity during climbing. However, as intermediaries between the arboreal and terrestrial environment, semi-arboreal mammals appear not extremely specialized and, thus, anatomical adaptations may be less evident than expected for arboreal climbers. Here, we present quantitative data on the muscle anatomy of the forelimbs (N = 14) of two closely related species of Mustelidae and relate the findings to their locomotor habits. The arboreal pine marten (Martes martes) and the more terrestrial stone marten (Martes foina) are the most similar sympatric carnivores in Europe, but distinctly differ in habitat selection and locomotor mode. Via dissections muscle architectural variables including muscle mass, pennation angle, and fiber length were measured and the physiological cross-sectional area and maximum isometric force were estimated for each muscle. The results reveal that the force-generating capacity of the limb flexor and retractor muscles and the excursion capability of the adductor muscles are greater in the pine marten compared to the stone marten. Since the two sympatric martens are very similar in terms of overall appearance, body size, intra-limb proportions, phylogenetic relationships and predation behavior, the differences in forelimb musculature are interpreted to reflect the greater climbing ability of the pine marten. The functional properties appear to facilitate locomotion in a three-dimensionally complex arboreal environment. Anat Rec, 301:449-472, 2018. © 2018 Wiley Periodicals, Inc.

Feeding capability in the extinct giant Siamogale melilutra and comparative mandibular biomechanics of living Lutrinae.

At 50 kg in estimated weight, the extinct Siamogale melilutra is larger than all living otters, and ranks among the largest fossil otters. The biomechanical capability of S. melilutra jaws as related to their large size is unknown but crucial to reconstructing the species' potentially unique ecological niche. Here we compare the mandibular biomechanics of S. melilutra using engineering-based performance measures against ten extant otter biomechanical models. Despite a wide range of feeding preferences from durophagy to piscivory, living otter species exhibit a linear relationship between mandible stiffness and volume, as expected in isometric model scaling. In contrast, S. melilutra models exhibit a six-fold increase in stiffness from expected stiffness-volume relationships calculated from extant species models. Unlike stiffness, mechanical efficiency of biting is conserved among living otters and in S. melilutra. These findings indicate that although similar to living bunodont otters in morphology and biting efficiency, jaw strength in S. melilutra far surpasses molluscivores such as sea otters and Cape clawless otters, even after accounting for size. Therefore, Siamogale represents a feeding ecomorphology with no living analog, and its giant size and high mandibular strength confer shell-crushing capability matched only by other extinct molluscivores such as the marine bear Kolponomos.

A Comparison of Visual and Genetic Techniques for Identifying Japanese Marten Scats - Enabling Diet Examination in Relation to Seasonal Food Availability in a Sub-Alpine Area of Japan.

We compared the reliability of visual diagnostic criteria to DNA diagnostic techniques, including newly designed primers, to discriminate Japanese marten (Martes melampus) feces from those of other sympatric carnivore species. Visual criteria proved > 95% reliable for fresh, odoriferous scats in good condition. Based upon this verification, we then examined if and how Japanese marten diet differs among seasons at high elevation study site (1500-2026 m). We also considered how intra-specific competition with the Japanese red fox (Vulpes vulpes japonica) may shape marten feeding ecology. From 120 Japanese marten fecal samples, high elevation diet comprised (frequency of occurrence) 30.6-66.0% mammals, 41.0-72.2% insects and 10.6-46.2% fruits, subject to seasonal variation, with a Shannon-Weaver index value of 2.77. These findings contrast substantially to seasonal marten diet reported in adjacent lowland regions (700-900 m), particularly in terms of fruit consumption, showing the trophic adaptability of the Japanese marten. We also noted a substantial dietary overlap with the red fox (n = 26 scats) with a Shannon-Weaver index of 2.61, inferring little trophic niche mutual exclusion (trophic niche overlap: 0.95), although some specific seasonal prey selection differences were likely related to relative differences in body size between foxes and martens. This additional information on the feeding ecology of the Japanese marten enables a better assessment of the specific risks populations face in mountainous regions.