Twinning in wild, endangered lion-tailed macaques Macaca silenus in the Anamalai Hills of the Western Ghats, India.

Many primate species show various behavioural and ecological adaptations to provisioning, one of which is the unusual occurrence of twins. Here, we report observations on two pairs of surviving twins in lion-tailed macaques Macaca silenus in the Anamalai Hills of the Western Ghats, India. The Puthuthottam population of lion-tailed macaques has historically been restricted to a rainforest fragment measuring 92 ha, situated adjacent to human settlements. Over the last 10 years, however, several groups from this population have begun to directly interact with the local human communities, visiting settlements at a rate of 0.52 events/day and exploiting various anthropogenic food resources. We followed and opportunistically collected behavioural ad libitum data on two sets of twins for a year, between March 2019 and March 2020. Both of the mothers were primarily terrestrial, although the mother with the younger set of twins also used the tree canopy and other precarious substrates, such as cables. Although two previous cases of twinning have been reported in this population, one in the late 1990s and one between 2000 and 2002, neither of those sets of twins survived beyond a few weeks, with at least one infant in each pair dying of unknown causes. We discuss, but discount, the possibility that one of the infants in either set of twins was an adoptee. Our observations indicate that some lion-tailed macaque twins can survive under free-ranging conditions if they receive adequate care from their biological mother or another female. Our findings also provide further evidence of increased rates of twinning as a consequence of dietary changes in synanthropic non-human primate populations.

Winter foraging ecology of stump-tailed macaques Macaca arctoides in the Hollongapar Gibbon Sanctuary, Assam, India.

Frugivorous primates in temperate and subtropical regions often experience a shortage or complete absence of fruits for several months of the year. We studied the foraging ecology of a group of stump-tailed macaques Macaca arctoides in a subtropical forest during winter, when fruit abundance was low. We conducted this study in the Hollongapar Gibbon Sanctuary, Assam, India, from December 2015 to April 2016. We estimated the time-activity budgets, diet, and habitat use of the study troop and also conducted vegetation sampling and phenological monitoring of the study area. The stump-tailed macaque troop spent about 73.2% of its time foraging and feeding, with seasonal differences in food species intake and in habitat use. Open degraded forests were primarily used in December, January, and February, when the macaques largely fed on shoots of the bamboo Schizostachyum polymorphum and roots of the herb Forrestia (= Amischotolype) mollissima, while they mostly utilised F. mollissima in canopy-covered, degraded forests in March and April. There was a major shift from a primary diet of fruits in the wet season, reported from earlier studies, to possibly relatively poorquality, but abundant, shoots and roots in winter. This suggests that the consumption of these poor-quality fallback food species is a key dietary adaptation of the macaques to periods of fruit scarcity. Although our preliminary study suggests that the feeding behaviour of the stump-tailed macaque in its subtropical semievergreen forest habitat appears to be similar to that of its congeneric species in temperate forests, further investigations are needed to firmly establish the observed foraging patterns of this vulnerable cercopithecine species in its last lowland rainforest refuge in northeastern India.

Yes, we have the power to end TB!

Robust efforts are essential to sustain and increase the advancements made in battling TB, as well as to tackle persistent issues that have caused the fight against the disease to be uneven. The End TB Strategy proposes that new technologies are to be developed by 2025 to encourage a quick growth in TB occurrence diminishment. This calls for a cross-sectoral focus on creating and distributing suitable medical and programmatic modernizations in a fair manner. However, many difficulties and differences still exist in the realms of research and development regarding vaccines, drugs, technical advances, and services related to TB. Therefore, priority needs to be given to overcoming these difficulties and discrepancies for a better future. On World TB Day 2023, SEAR Union, TB Alliance, the National Institute of Advanced Studies (NIAS) and Open Source Pharma Foundation (OSPF) gathered to discuss an important topic under the heading: "YES, WE HAVE THE POWER TO END TB!" With a commitment to putting the patient first and increasing their collective efforts, the organizations recognized that it is possible to make this goal a reality. The organizations involved in the discussion have declared their commitment to engaging in collaborative efforts to end TB globally. They advocate for strengthening access to TB services, controlling and preventing TB, improving surveillance and drug resistance management, and investing in research and development. Furthermore, they recognize the importance of reducing stigma and integrating patient voices in this endeavour. This Round Table serves as a framework to build on and ensure that the goal of ending TB is achievable.

Far from home: The synurbisation of a rainforest-evolved primate, the lion-tailed macaque Macaca silenus, and its recent adaptations to anthropogenic habitats in southern India.

The lion-tailed macaque is an endangered species, endemic to the Western Ghats of southern India. The Anamalai hills harbour 63 groups of the species, several of which occur in rainforest fragments, amidst tea and coffee plantations, on the Valparai plateau. Being highly arboreal, these populations have always been assumed to be largely restricted to their fragmented forest patches and possibly unable to navigate successfully through the surrounding plantation-human habitation matrix. While adult males have occasionally been sighted along roadsides between forest fragments, we now provide evidence for the emigration of an entire troop out of a forest fragment into nearby human settlements, leading to the inclusion of areas completely devoid of natural vegetation into the core home range of the troop. We argue that a combination of hostile inter-troop encounters, a natural urge to expand their range and the discovery of novel and relatively easily accessible food resources may have led to such unusual ranging patterns, accompanied by significant changes in troop behavioural profiles, which we consider as inexorable processes of synurbisation.

Blowing the lid off! Bottle-directed, extractive foraging strategies in synurbic bonnet macaques Macaca radiata in southern India.

Nonhuman individuals and groups, living in anthropogenic landscapes, often adopt adaptive foraging strategies, mediated by their day-to-day interactions with humans and their artefacts. Exploring such novel behavioral manifestations, especially in the Anthropocene, offers us insights into behavioral innovations and their transmission in such rapidly changing ecologies. In this study, employing field experiments, we investigated an example of human-induced, extractive foraging behavior - the extraction of liquid contents from plastic bottles - in a synurbic bonnet macaque Macaca radiata population. The main aims of the study were to examine the distribution, diversity, inter-individual variability and intra-individual flexibility of bottle-directed manipulative behaviors, and to explore the social and environmental factors driving this behavioral practice. We video-recorded the manipulation of partially filled plastic bottles and the extraction of liquid across four groups of bonnet macaques in southern India. Two socio-demographic factors - age class and group membership - and one environmental factor - food provisioning - were identified as major determinants of inter-individual variation in the performance of sophisticated manipulative techniques and in bottle-opening success. Our results also suggest that age-related physical maturation, experiential trial-and-error learning, and possibly social learning contributed to the acquisition of foraging competence in this task. These findings illuminate the mechanisms underlying inter-individual behavioral variability and intra-individual behavioral flexibility amongst free-ranging individuals of a cercopithecine primate species, traditionally known for its ecological adaptability and behavioral plasticity. Finally, this study documents how the presence of humans, their artefacts and their activities facilitate the development of certain behavioral traditions in free-ranging nonhuman populations, thus providing valuable insights into how human-alloprimate relations can be restructured within the increasingly resource-competitive environments of the Anthropocene.

Size matters! The largest wild stump-tailed macaque Macaca arctoides troop ever reported, located in the Hollongapar Gibbon Sanctuary, northeastern India.

Very large and stable, socially coherent primate groups, not including fission-fusion societies, are usually rare in nature, owing to constraints imposed by various ecological and social factors. Moreover, unlike species in open habitats, those in forests tend to have smaller groups, and this becomes further accentuated in small and fragmented forest patches. We report here an unusually large troop of stump-tailed macaques Macaca arctoides from the Hollongapar Gibbon Sanctuary, a small and isolated lowland tropical rainforest patch in the Upper Brahmaputra Valley of northeastern India - this is possibly the largest wild group of the species recorded anywhere across its distribution range. We hypothesise the potential factors driving the formation of such a large social group of this vulnerable cercopithecine primate and discuss the conservation implications of this phenomenon.

Mental health ecologies and urban wellbeing.

How might urban mental health be understood when animals reconfigure human wellbeing in the lived city? Drawing upon ethnographic fieldwork on people and macaques in New Delhi and forging novel conversations between urban studies, ecology and psychiatry, our ontology of urban mental health moves from lived experience of the built environment to those configured by dwelling with various interlocutors: animals, astral bodies and supernatural currents. These relations create microspaces of wellbeing, keeping forces of urban precarity at bay. This paper discusses mental health ecologies in different registers: subjectivity being environmental, its scale being relational rather than binary, enmeshed in the dynamics of other-than-human life, and involving conversations between medical and vernacular practices rather than hierarchies of knowledge.

Changing ecologies, shifting behaviours: Behavioural responses of a rainforest primate, the lion-tailed macaque Macaca silenus, to a matrix of anthropogenic habitats in southern India.

With the uncontrolled expansion of anthropogenic modifications of the environment, wildlife species are forced to interact with humans, often leading to conflict situations that have detrimental effects for both wildlife and humans. Such interactions are escalating globally, making it crucial for us to devise strategies for both, the management of conflict and the conservation of these often-threatened species. We studied a case of potentially detrimental human-wildlife interactions between an endemic, habitat-specialist primate, the lion-tailed macaque Macaca silenus and resident human communities that has developed in recent years in the Western Ghats mountains of southern India. Primates provide useful model systems to understand the extent and nature of behavioural changes exhibited by wildlife in response to anthropogenic habitats with varying degrees of human influence. We documented behaviours, including foraging and intra-species social interactions, to examine the decisions made by the macaques as they exploited four human-modified habitats, which, for the purpose of this study, have been qualitatively characterised to include structural features of the habitat, type of food resources available and the presence of humans. Access to human-origin food, either cooked or packaged, acquired directly from homes or garbage pits, in the human-dominated habitat appeared to significantly reduce active foraging and searching for food, allowing them to engage in other behavioural activities, such as resting. Furthermore, patterns of reciprocated affiliation dissipated in certain human-dominated habitats, with individuals seeming to have adopted novel behavioural strategies, leading to altered social dynamics in the troop, possibly in response to provisioning. This study thus highlights the importance of understanding behavioural changes displayed by animals in response to human interactions; such knowledge could be crucial for the planning and implementation of management and conservation strategies for endangered species such as the lion-tailed macaque and possibly other wildlife in the increasingly anthropogenic landscapes of the tropical world.

Gestural communication of wild bonnet macaques in the Bandipur National Park, Southern India.

Nonhuman primate gestures are believed to be crucial evolutionary precursors of human language. Comparative studies on primate gestures in an evolutionary framework have, however, remained largely restricted to the great apes and the potential flexibility and richness of gestural communication in monkeys, especially in the wild, continue to be virtually unknown. In this paper, we followed several criteria, adapted from ape gesture studies, to identify gestures and evaluate their contexts of usage in the repertoire of wild bonnet macaques Macaca radiata in the Bandipur National Park of southern India. This report is the first of its kind to systematically identify gestures in any wild, non-ape species, thus providing a platform for comparative studies across primate taxa, particularly in our efforts to trace out the phylogenetic origins of language-like markers in the primate lineage, earlier than in the great apes.

All-Male Groups in Asian Elephants: A Novel, Adaptive Social Strategy in Increasingly Anthropogenic Landscapes of Southern India.

Male Asian elephants are known to adopt a high-risk high-gain foraging strategy by venturing into agricultural areas and feeding on nutritious crops in order to improve their reproductive fitness. We hypothesised that the high risks to survival posed by increasingly urbanising and often unpredictable production landscapes may necessitate the emergence of behavioural strategies that allow male elephants to persist in such landscapes. Using 1445 photographic records of 248 uniquely identified male Asian elephants over a 23-month period, we show that male Asian elephants display striking emergent behaviour, particularly the formation of stable, long-term all-male groups, typically in non-forested or human-modified and highly fragmented areas. They remained solitary or associated in mixed-sex groups, however, within forested habitats. These novel, large all-male associations, may constitute a unique life history strategy for male elephants in the high-risk but resource-rich production landscapes of southern India. This may be especially true for the adolescent males, which seemed to effectively improve their body condition by increasingly exploiting anthropogenic resources when in all-male groups. This observation further supports our hypothesis that such emergent behaviours are likely to constitute an adaptive strategy for male Asian elephants that may be forced to increasingly confront anthropogenically intrusive environments.

Physiological stress responses in wild Asian elephants Elephas maximus in a human-dominated landscape in the Western Ghats, southern India.

Increasing anthropogenic pressures on forests, especially in the tropical regions of the world, have restricted several large mammalian species such as the Asian elephant to fragmented habitats within human-dominated landscapes. In this study, we assessed the effects of an anthropogenic landscape and its associated conflict with humans on the physiological stress responses displayed by Asian elephants in the Anamalai Hills of the Western Ghats mountains in south India. We have quantified faecal glucocorticoid metabolite (FGM) concentrations in focal individual elephants within and across herds, inhabiting both anthropogenic and natural habitats, and evaluated their physiological responses to different socio-ecological situations between November 2013 and April 2014. Physiological stress responses varied significantly among the tested elephant age- and sex categories but not across different types of social organisation. Adults generally showed higher FGM concentrations, even in the absence of stressors, than did any other age category. Males also appeared to have higher stress responses than did females. Although there was no significant variation in mean stress levels between elephants on the plateau in the absence of human interactions and those in adjacent, relatively undisturbed forest habitats, FGM concentrations increased significantly for adult and subadult individuals as well as for calves following drives, during which elephants were driven off aggressively by people. Our study emphasises the general importance of understanding individual variation in physiology and behaviour within a population of a seriously threatened mammalian species, the Asian elephant, and specifically highlights the need for long-term monitoring of the stress physiology and behavioural responses of individual elephants across both human-dominated and natural landscapes. Such studies would not only provide comprehensive insights into the adaptive biology of elephants in changing ecological regimes but also aid in the development of effective management and conservation strategies for endangered populations of the species.

Intentional communication between wild bonnet macaques and humans.

Comparative studies of nonhuman communication systems could provide insights into the origins and evolution of a distinct dimension of human language: intentionality. Recent studies have provided evidence for intentional communication in different species but generally in captive settings. We report here a novel behaviour of food requesting from humans displayed by wild bonnet macaques Macaca radiata, an Old World cercopithecine primate, in the Bandipur National Park of southern India. Using both natural observations and field experiments, we examined four different behavioural components-coo-calls, hand-extension gesture, orientation, and monitoring behaviour-of food requesting for their conformity with the established criteria of intentional communication. Our results suggest that food requesting by bonnet macaques is potentially an intentionally produced behavioural strategy as all the food requesting behaviours except coo-calls qualify the criteria for intentionality. We comment on plausible hypotheses for the origin and spread of this novel behavioural strategy in the study macaque population and speculate that the cognitive precursors for language production may be manifest in the usage of combination of signals of different modalities in communication, which could have emerged in simians earlier than in the anthropoid apes.

Not here, there! Possible referential gesturing during allogrooming by wild bonnet macaques, Macaca radiata.

Intentional referential gestures, a fundamental building block of symbolic human language, have been reported from a range of species, including non-human primates. While apes are known to spontaneously use intentional gestures, only captive macaques, amongst non-ape primates, appear to intentionally display learnt gestures. On the other hand, referential gestures have so far been reported only in chimpanzees, amongst non-human primates. We document here, for the first time, potentially referential gesturing, used intentionally as well, in a monkey species, the bonnet macaque Macaca radiata, in the wild. Bonnet macaques use four distinct actions during allogrooming, possibly to indicate a particular body part intended to be groomed. These acts were successful in drawing the recipients' attention to the indicated part, which they began to groom subsequently. This study enriches our understanding of non-ape primate gestural communication and adds to the growing evidence for early human language-like capacities in non-human species.

Watering holes: The use of arboreal sources of drinking water by Old World monkeys and apes.

Water is one of the most important components of an animal's diet, as it is essential for life. Primates, as do most animals, procure water directly from standing or free-flowing sources such as pools, ponds and rivers, or indirectly by the ingestion of certain plant parts. The latter is frequently described as the main source of water for predominantly arboreal species. However, in addition to these, many species are known to drink water accumulated in tree-holes. This has been commonly observed in several arboreal New World primate species, but rarely reported systematically from Old World primates. Here, we report observations of this behaviour from eight great ape and Old World monkey species, namely chimpanzee, orangutan, siamang, western hoolock gibbon, northern pig-tailed macaque, bonnet macaque, rhesus macaque and the central Himalayan langur. We hypothesise three possible reasons why these primates drink water from tree-holes: (1) coping with seasonal or habitat-specific water shortages, (2) predator/human conflict avoidance, and (3) potential medicinal benefits. We also suggest some alternative hypotheses that should be tested in future studies. This behaviour is likely to be more prevalent than currently thought, and may have significant, previously unknown, influences on primate survival and health, warranting further detailed studies.

Sensory cues employed for the acquisition of familiarity-dependent recognition of a shoal of conspecifics by climbing perch (Anabas testudineus Bloch).

In this study we showed that a freshwater fish, the climbing perch (Anabas testudineus) is incapable of using chemical communication but employs visual cues to acquire familiarity and distinguish a familiar group of conspecifics from an unfamiliar one. Moreover, the isolation of olfactory signals from visual cues did not affect the recognition and preference for a familiar shoal in this species.

Quaternary climate change and social behavior shaped the genetic differentiation of an endangered montane primate from the southern edge of the Tibetan Plateau.

Multiple factors, including climate change, dispersal barriers, and social behavior influence the genetic structure of natural populations. While the effects of extrinsic factors such as historical climatic change and habitat topography have been well studied, mostly in temperate habitats, the simultaneous effects of intrinsic factors such as social behavior on genetic structure have rarely been explored. Such simultaneous effect, however, may particularly be common in social mammals such as many primates. Consequently, we studied the population structure of a rare and endangered social primate, the Arunachal macaque Macaca munzala, endemic to the northeastern Indian state of Arunachal Pradesh, located on the subtropical southern edge of the Tibetan Plateau and forming part of the Eastern Himalayan biodiversity hotspot. We studied a 534 bp-long mitochondrial DNA sequence and 22 autosomal microsatellite loci in individuals from three populations, Tawang, Upper Subansiri, and West Siang. The mtDNA data revealed three major divergence events: that between the Arunachal and bonnet macaques (ca. 1.61 mya), the founding of the West Siang population and the ancestral population of the present-day bonnet macaques (ca. 1.32 mya), and the divergence between the Tawang and Upper Subansiri populations (ca. 0.80 mya) that coincided with the major glacial events in the region. Comparing mitochondrial DNA with autosomal microsatellites, we also found evidence for female philopatry and male-driven long-distance gene flow. Arunachal macaques thus appear to be characterized by groups of philopatric females separated by geographical barriers and harsh climate but with dispersing males exerting a homogenizing effect on the nuclear gene pool. Given that severe population differentiation is of major concern in species conservation, we suggest that our study populations represent significant conservation units of this rare, endangered primate but, more importantly, emphasize the complex interplay of extrinsic and intrinsic factors in shaping the population structure of a social mammalian species.

Mixed fortunes: ancient expansion and recent decline in population size of a subtropical montane primate, the Arunachal macaque Macaca munzala.

Quaternary glacial oscillations are known to have caused population size fluctuations in many temperate species. Species from subtropical and tropical regions are, however, considerably less studied, despite representing most of the biodiversity hotspots in the world including many highly threatened by anthropogenic activities such as hunting. These regions, consequently, pose a significant knowledge gap in terms of how their fauna have typically responded to past climatic changes. We studied an endangered primate, the Arunachal macaque Macaca munzala, from the subtropical southern edge of the Tibetan plateau, a part of the Eastern Himalaya biodiversity hotspot, also known to be highly threatened due to rampant hunting. We employed a 534 bp-long mitochondrial DNA sequence and 22 autosomal microsatellite loci to investigate the factors that have potentially shaped the demographic history of the species. Analysing the genetic data with traditional statistical methods and advance Bayesian inferential approaches, we demonstrate a limited effect of past glacial fluctuations on the demographic history of the species before the last glacial maximum, approximately 20,000 years ago. This was, however, immediately followed by a significant population expansion possibly due to warmer climatic conditions, approximately 15,000 years ago. These changes may thus represent an apparent balance between that displayed by the relatively climatically stable tropics and those of the more severe, temperate environments of the past. This study also draws attention to the possibility that a cold-tolerant species like the Arunachal macaque, which could withstand historical climate fluctuations and grow once the climate became conducive, may actually be extremely vulnerable to anthropogenic exploitation, as is perhaps indicated by its Holocene ca. 30-fold population decline, approximately 3,500 years ago. Our study thus provides a quantitative appraisal of these demographically important events, emphasising the ability to potentially infer the occurrence of two separate historical events from contemporary genetic data.

Local and landscape correlates of primate distribution and persistence in the remnant lowland rainforests of the Upper Brahmaputra Valley, northeastern India.

Habitat fragmentation affects species distribution and abundance, and drives extinctions. Escalated tropical deforestation and fragmentation have confined many species populations to habitat remnants. How worthwhile is it to invest scarce resources in conserving habitat remnants within densely settled production landscapes? Are these fragments fated to lose species anyway? If not, do other ecological, anthropogenic, and species-related factors mitigate the effect of fragmentation and offer conservation opportunities? We evaluated, using generalized linear models in an information-theoretic framework, the effect of local- and landscape-scale factors on the richness, abundance, distribution, and local extinction of 6 primate species in 42 lowland tropical rainforest fragments of the Upper Brahmaputra Valley, northeastern India. On average, the forest fragments lost at least one species in the last 30 years but retained half their original species complement. Species richness declined as proportion of habitat lost increased but was not significantly affected by fragment size and isolation. The occurrence of western hoolock gibbon (Hoolock hoolock) and capped langur (Trachypithecus pileatus) in fragments was inversely related to their isolation and loss of habitat, respectively. Fragment area determined stump-tailed (Macaca arctoides) and northern pig-tailed macaque occurrence (Macaca leonina). Assamese macaque (Macaca assamensis) distribution was affected negatively by illegal tree felling, and rhesus macaque (Macaca mulatta) abundance increased as habitat heterogeneity increased. Primate extinction in a fragment was primarily governed by the extent of divergence in its food tree species richness from that in contiguous forests. We suggest the conservation value of these fragments is high because collectively they retained the entire original species pool and individually retained half of it, even a century after fragmentation. Given the extensive habitat and species loss, however, these fragments urgently require protection and active ecological restoration to sustain this rich primate assemblage.

Positive interactions between irrawaddy dolphins and artisanal fishers in the Chilika Lagoon of eastern India are driven by ecology, socioeconomics, and culture.

In human-dominated landscapes, interactions and perceptions towards wildlife are influenced by multidimensional drivers. Understanding these drivers could prove useful for wildlife conservation. We surveyed the attitudes and perceptions of fishers towards threatened Irrawaddy dolphins (Orcaella brevirostris) at Chilika Lagoon India. To validate the drivers of fisher perceptions, we : (1) observed dolphin foraging behavior at stake nets, and (2) compared catch per unit effort (CPUE) and catch income of fishers from stake nets in the presence and absence of foraging dolphins. We found that fishers were mostly positive towards dolphins, believing that dolphins augmented their fish catch and using culture to express their perceptions. Foraging dolphins were observed spending half their time at stake nets and were associated with significantly higher catch income and CPUE of mullet (Liza sp.), a locally preferred food fish species. Wildlife conservation efforts should use the multidimensional drivers of human-wildlife interactions to involve local stakeholders in management.

Comparative demography of two commensal macaques in India: implications for population status and conservation.

Rhesus and bonnet macaques are among the most common primates found in India and have been categorised as being of Least Concern by the IUCN. Despite the wealth of information on their ecology and behaviour, little attention has been paid to their demography or population status. We studied the demographic status of the two species along their common distribution zone in western, central and south-eastern India. Bonnet macaques were largely found in forest areas whereas rhesus macaques were observed more often in human-dominated habitats. The troop sizes of the two species also tended to be largest in different habitats, bonnet macaques in forested areas and rhesus macaques in urban areas. We suggest that the presence of large numbers of rhesus macaques in anthropogenic areas in south-eastern India is not a natural phenomenon but has been caused by human intervention. The bonnet macaque population has decreased in number in the common distribution zone, and as this species, unlike the rhesus macaque, is endemic to India, we strongly recommend the need to reassess its conservation status.