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The taxonomy of the Hanuman langur (Sem-nopithecus spp.), a widely distributed Asian colobine monkey, has been in a flux for a long time due to much disagreement between various classification schemes. However, results from a recent field-based morphological study were consistent with Hill's (Ceylon J Sci 21:277–305, 1939) species level classificat...
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... show the occurrence of two species, i.e. black-footed gray langur Semnopithecus hypoleucos and gray-tufted Langur Semnopithecus priam in the Western Ghats [12][13][14] . We added rhesus macaque and two species of langurs instead of one species of Hanuman langur to the list of primates. ...
... M. silenus are confined to a narrow strip of rainforests south of Aghanashini River in the central Western Ghats to the southern tip of the hill system 27,28 . The northern limit of the distribution range of Nilgiri langurs S. johnii marks Brahmagiri Hills in the central Western Ghats, whereas S. hypoleucos replaces the same niche at the north of these hills, and S. priam occupies the rainshadow areas, especially the eastern slopes of the Western Ghats 12,14,28 . ...
An updated list confirms the presence of 134 species of wild mammals in the Western Ghats, India. The superimposed distribution range of all, and threatened species of mammals depicts the potential mammalian key diversity areas for the Western Ghats, which can be prioritized for long-term conservation. These mammalian key diversity areas are confined to the central and the southern Western Ghats. The most crucial key diversity areas for both threatened and all mammalian species occur in Pushpagiri-Talakaveri, the Nilgiri Biosphere, the Anamalai Hills, the Periyar landscape and the Agas-tyamalai Hills.
... These studies have enabled researchers to identify a range of directly observable and cryptic hybridization phenomena that played a role in the evolutionary diversification of this subfamily. For example, morphological (coloration), bioacoustic, and molecular evidence suggest both observable hybridization and cryptic introgression of genes between ecologically distinct langurs that co-inhabit the mosaic of evergreen and deciduous forest in the south of Indian subcontinent (Semnopithecus johnii, S. priam, and possibly S. hypoleucos) (Hohman, 1988;Ashalakshmi et al., 2015;Nag, 2020). Hybridization between Semnopithecus priam thersites and S. vetulus in Sri Lanka is supported by behavioral evidence and observation of coat color pattern (Lu et al., 2020). ...
Interspecific hybridization in primates is common but hybridization between distantly related sympatric primate species is rarely observed in the wild. We present evidence for a possible hybridization event between Nasalis larvatus and Trachypithecus cristatus in the Lower Kinabatangan Wildlife Sanctuary, Sabah, through assessment of photographs. We used a set of categorical characters and metric measurements to compare the putative hybrid with the likely parent species. Nonmetric comparison showed that this "mystery monkey" is intermediate in several characters. Measurements of limb proportions on photographs showed that the brachial, humerofemoral, and intermembral indexes are above 100 for N. larvatus and below 100 for T. cristatus on all photographs, whereas the crural index is higher than 100 in both species and the distributions of this index in the two species overlap. Brachial and intermembral indices of the putative hybrid were similar to those of N. larvatus. Crural and humerofemoral indices were closer to the values for T. cristatus than those of N. larvatus. Multiple observers confirmed the occurrence of mixed-species groups in the area, and interspecific mating has been photographed. The putative hybrid is now an adult female and was last photographed in September 2020 with an infant and swollen breast, suggesting lactation. We propose further noninvasive fecal sampling for genetic analyses to confirm the origins of this "mystery monkey." This case of hybridization may be related to anthropogenic changes to the landscape, whereby expansion of oil palm plantations confines N. larvatus and T. obscurus to narrow riverine forest patches along the Kinabatangan. This observation therefore also may have conservation implications, indicating limited mate access and dispersal opportunities for these threatened primates.
Supplementary information:
The online version contains supplementary material available at 10.1007/s10764-022-00293-z.
... These two genera together have the highest species diversity among all the colobine genera (Roos et al. 2014). There has been much controversy in the taxonomy of these two genera (Oates et al. 1994;Groves 2001;Brandon-Jones et al. 2004); however, with the advent of molecular tools many of these issues have been resolved Ashalakshmi et al. 2014;Arekar et al. 2021). Yet, the taxonomic placement of two species, currently in the genus Trachypithecus, continues to be in debate; these include the endangered golden langur (Trachypithecus geei) and capped langur (Trachypithecus pileatus). ...
The phylogenetic position of the capped and golden langur (CG) lineage has been ambiguous owing to the discordance between phylogenies from multiple molecular markers. Previous molecular studies have hypothesised that this discordance likely arises from either a hybridization event that took place between the Indian genus Semnopithecus and the Southeast Asian genus Trachypithecus or from incomplete lineage sorting (ILS). Distinguishing between hybridization and ILS is challenging and these processes can lead to serious difficulties in inferring phylogenies. In this study, we used genetic markers (nine nuclear and eight mitochondrial) in conjunction with coalescent based species tree approach and a test for hybridization using posterior predictive checking to better understand the evolutionary origin of the CG lineage. Both the concatenated nuclear as well as the mitochondrial dataset recovered congruent relationships where CG lineage was sister to Trachypithecus. However, nuclear species tree estimated using different multispecies coalescent methods suggested an opposite result, i.e. CG lineage was sister to Semnopithecus. Hybridization analysis strongly indicates gene flow between Semnopithecus and Trachypithecus that likely gave rise to the hybrid CG lineage. Further, the CG lineage is morphologically intermediate between Semnopithecus and Trachypithecus with respect to skull and body measurements. In light of the above evidences, we argue that the CG lineage needs to be elevated to a new genus of its own. Taxonomic and conservation implications of these results are also discussed.
... Gray langurs (Semnopithecus entellus), commonly called Hanuman langurs have colonized various parts of the Indian subcontinent, ranging from the desert to forest fringes, and have lived with a diversified resource structure and human interference (Oppenheimer, 1977;Ashalakshmi et al., 2014;Chetan et al., 2014). In comparison to the other species of langur, social organization of the gray langur is highly flexible (Newton, 1988;Caton, 1999;Sterck, 1999;Rajpurohit et al., 2006) and is often modified by the male-male competition followed by infanticides (Hrdy, 1974;Broom et al., 2004;Sharma et al., 2010). ...
Urbanization affects concurrent human-animal movements as a result of altered resource availability and land use pattern, which leads to considerable ecological consequences. While some animals find themselves adrift, homeless with the uncertainty of resources resulting from the urban encroachment, few of them manage to survive by altering their natural behavioural patterns, and co-exist with humans. Folivorous colobines, such as grey langur, whose feeding repertoire largely consists of plant parts, tend to be more attuned to the urban high-calorie food sources to attain maximum fitness benefits within the concrete jungle having an insignificant green cover. However, such a mismatch between their generalized feeding behaviour and specialized gut physiology reminds us of the Liem’s paradox and demands considerable scientific attention which could tell us the story behind colobines’ successful co-existence within human settlements. Besides understanding their population dynamics, the effective management of these urbanized, free-ranging, non-human primate populations also depends on their altered feeding preferences, altogether which could lead us to the development of an ecologically sound urban ecosystem. Here, we have used a field-based experimental set up which allows langurs to choose between natural and urban food options, being independent of any inter-specific conflicts over resources due to food scarcity. The multinomial logit model reveals the choice-based decision making of these free-ranging grey langurs in an urban settlement of West Bengal, India, where they have not only learned to approach the human-provisioned urban food items but also shown a keen interest in it. While urbanization imposes tremendous survival challenges to these animals, it also opens up for various alternative options for human-animal co-existence which is reflected in this study, and could guide us for the establishment of a sustainable urban ecosystem in the future.
HIGHLIGHTS
The feeding repertoire of free-ranging grey langurs at Dakshineswar largely consists of urban food items in contrast to the langurs of Nangi, and Nalpur who mostly depend on natural food sources.
High human-langur interactions together with the scarcity of natural plant-based food sources could be considered as an intriguing driving force behind langurs’ altered feeding habits in Dakhineswar.
The field-based experimental set up allows free-ranging langurs to choose between natural and urban food options in an urban settlement like Dakhineswar.
Urban food items outperformed natural food items as the most chosen one, indicating langurs’ altered feeding preferences which facilitate their successful co-existence within an urban ecosystem.
... Gray langurs (Semnopithecus entellus), commonly called Hanuman langurs have colonized various parts of the Indian subcontinent, ranging from the desert to forest fringes, and have lived with a diversified resource structure and human interference (Oppenheimer, 1977;Ashalakshmi et al., 2014;Chetan et al., 2014). In comparison to the other species of langur, social organization of the gray langur is highly flexible (Newton, 1988;Caton, 1999;Sterck, 1999;Rajpurohit et al., 2006) and is often modified by the male-male competition followed by infanticides (Hrdy, 1974;Broom et al., 2004;Sharma et al., 2010). ...
... Gray langurs (Semnopithecus entellus), commonly called Hanuman langurs have colonized various parts of the Indian subcontinent, ranging from the desert to forest fringes, and have lived with a diversified resource structure and human interference (Oppenheimer, 1977;Ashalakshmi et al., 2014;Chetan et al., 2014). In comparison to the other species of langur, social organization of the gray langur is highly flexible (Newton, 1988;Caton, 1999;Sterck, 1999;Rajpurohit et al., 2006) and is often modified by the male-male competition followed by infanticides (Hrdy, 1974;Broom et al., 2004;Sharma et al., 2010). ...
Urbanization affects concurrent human-animal interactions as a result of altered resource availability and land use pattern, which leads to considerable ecological consequences. While some animals have lost their habitat due to urban encroachment, few of them managed to survive within the urban ecosystem by altering their natural behavioral patterns. The feeding repertoire of folivorous colobines, such as gray langur, largely consists of plant parts. However, these free-ranging langurs tend to be attuned to the processed high-calorie food sources to attain maximum benefits within the concrete jungle having insignificant greenery. Therefore, besides understanding their population dynamics, the effective management of these urbanized, free-ranging, non-human primate populations also depends on their altered feeding habits. Here, we have used a field-based experimental setup that allows gray langurs to choose between processed and unprocessed food options, being independent of any inter-specific conflicts over resources due to food scarcity. The multinomial logit model reveals the choice-based decision-making of these free-ranging gray langurs in an urban settlement of West Bengal, India, where they have not only learned to recognize the human-provisioned processed food items as an alternative food source but also shown a keen interest in it. However, such a mismatch between the generalized feeding behavior of folivorous colobines and their specialized gut physiology reminds us of Liem's paradox and demands considerable scientific attention. While urbanization imposes tremendous survival challenges to these animals, it also opens up for various alternative options for surviving in close proximity to humans which is reflected in this study, and could guide us for the establishment of a sustainable urban ecosystem in the future.
... Gray langurs (Semnopithecus entellus), commonly called Hanuman langurs have colonized various parts of the Indian subcontinent, ranging from the desert to forest fringes, and have lived with a diversified resource structure and human interference (Oppenheimer, 1977;Ashalakshmi et al., 2014;Chetan et al., 2014). In comparison to the other species of langur, social organization of the gray langur is highly flexible (Newton, 1988;Caton, 1999;Sterck, 1999;Rajpurohit et al., 2006) and is often modified by the male-male competition followed by infanticides (Hrdy, 1974;Broom et al., 2004;Sharma et al., 2010). ...
... The Tapti-Godavari rivers in central India form the borderline with NT distributed to the north and ST distributed to the south of these rivers (Roonwal, 1979(Roonwal, , 1984. Recent studies support the splitting of ST Hanuman langur into two species, namely Semnopithecus priam Blyth, 1844 and Semnopithecus hypoleucos Blyth, 1841, based on an integrative approach wherein multiple lines of evidence from molecular, morphological, and ecological data were used (Ashalakshmi et al., 2014;Nag et al., 2011Nag et al., , 2014. Similarly, genetic and morphological data suggest that the plains population of NT Hanuman langur is a separate species, Semnopithecus entellus Dufresne, 1797 (Karanth et al., 2010). ...
... With the advent of molecular techniques many recent studies have used genetic data to resolve taxonomic ambiguities in primates of the Indian subcontinent (Arekar et al., 2019;Ashalakshmi et al., 2014;Chakraborty et al., 2007;Karanth et al., 2008Karanth et al., , 2010Osterholz et al., 2008;Wangchuk et al., 2008). However, the use of molecular data does not guarantee a robust description and identification . ...
... iucnr edlist.org). We included our field data as well as published sequences from previous studies (Ashalakshmi et al., 2014;Karanth et al., 2010;Khanal et al., 2018). ...
Taxonomy is replete with groups where the species identity and classification remain unresolved. One such group is the widely distributed Hanuman langur (Colobinae: Semnopithecus). For most part of the last century, the Hanuman langur was considered to be a single species with multiple subspecies. Nevertheless, recent studies using an integrative taxonomy approach suggested that this taxon is a complex, with at least three species. However, these studies did not include the Himalayan population of the Hanuman langur whose taxonomic status remains unresolved. The Himalayan population of Hanuman langurs has been classified as a distinct species with multiple subspecies or been subsumed into other species. These classification schemes are wholly based on morphological characters which are sometimes insufficient to delimit different species. Here, we have integrated data from multiple sources viz. morphology, DNA, and ecology to resolve the taxonomy of the Himalayan langur and to understand its distribution limit. Our results with three lines of evidence corresponding to three different species concepts show that Himalayan langur is a species distinct from Semnopithecus entellus of the plains. Additionally, these results did not show any support for splitting of the Himalayan langur into multiple subspecies. Our study supports the classification proposed by Hill (Ceylon Journal of Science, XXI, 1939) and we recommend Semnopithecus schistaceus Hodgson, 1840 as species name for the Himalayan langur and subsume all the known subspecies into it.
... Semnopithecus hypoleucos achates is distributed widely in the Deccan peninsula from the eastern slopes of the Western Ghats, in comparatively drier areas (Nag et al. 2011Ashalakshmi et al. 2014). Semnopithecus hypoleucos aeneas (only found around Karnataka-Kerala border) has restricted range and is usually found alongside Niligiri Langur habitats and is a darker version of S. h. ...
... Semnopithecus hypoleucos iulus is distributed only in the Western Ghats from river Tapti in the north up to Bisleghat in Dakshina Kannada district of Karnataka. It is a wet zone subspecies compared to achates (Nag et al. 2011Ashalakshmi et al. 2014). ...
... comm.). Recent publication by Name et al. (2011Name et al. ( , 2014 and Ashalakshmi et al. (2014) delineates S. prima into two subspecies in southern India, viz., S. p. anchises, S. p. priam, and the Sri Lankan population as S. p. thersites. ...
... Ashalakshmi, N.C., Chetan Nag, K.S. and Karanth, P. 2014. Molecules support morphology: species status of South Indian populations of the widely distributed Hanuman langur. ...
