Singalila National Park is a national park in the Darjeeling district of West Bengal, India, situated on the Singalila Ridge at elevations over 2,134 meters (7,000 feet) above sea level, bordering Nepal to the west and Sikkim to the north.[1] Covering an area of 78.60 square kilometers, it was initially declared a wildlife sanctuary in 1986 and upgraded to a national park in 1992 to conserve its unique Himalayan ecosystems.[2] Renowned as a trekker's paradise, the park offers panoramic views of major Himalayan peaks including Kangchenjunga, Mount Everest, Lhotse, and Makalu, with popular routes leading to the highest point in West Bengal at Sandakphu (3,636 meters).[3]The park's diverse terrain spans temperate broad-leaved and mixed forests transitioning to alpine vegetation, featuring dense stands of bamboo, oak, magnolia, and rhododendron species that bloom vibrantly from March to May.[1] Wildflowers carpet the landscape in spring and post-monsoon seasons, while rare plants like the Himalayan Cobra Lily thrive at higher altitudes around Sandakphu.[1] As an Important Bird and Biodiversity Area (IBA), it hosts approximately 550 bird species, including the scarlet minivet and Kalij pheasant.[2]Singalila's fauna includes endangered mammals such as the red panda and Himalayan black bear, as well as leopards, barking deer, and the rare Himalayan newt in its streams.[1] The park's rhododendron forests and high-altitude meadows support a rich array of wildlife adapted to the Eastern Himalayas, making it a critical conservation zone within India's biodiversity hotspots.[3] Beyond ecology, it serves as a gateway for eco-tourism, with trekking trails like the Sandakphu-Phalut route drawing adventurers to experience its misty ridges and cultural heritage of nearby Lepcha and Nepali communities.[1]
History
Early Exploration
The Singalila region first drew significant scientific attention through the botanical expeditions of British naturalist Joseph Dalton Hooker in 1849. Accompanied by a party of 56 porters and assistants, Hooker traversed the Singalila Ridge starting from Tonglu, descending into the Tambur Valley in eastern Nepal as part of his broader exploration of passes west of Kangchenjunga. His work focused on cataloging the area's rich flora, particularly at high altitudes, where he documented numerous rhododendron species, including Rhododendron falconeri and Rhododendron roxburghii, noting their vibrant blooms and ecological adaptations in the subalpine zones. Hooker also recorded diverse orchids, such as those in the Lachen Valley, contributing to early understandings of the Himalayan plant diversity and publishing his findings in The Himalayan Journals (1854), which highlighted the region's botanical uniqueness.[4]In 1882, the British colonial administration acquired the Singalila forests, spanning approximately 66 square miles, from the Sikkim Durbar, integrating them into the expanding Darjeeling estate under direct control. This purchase was driven by economic imperatives, as the dense timber resources—rich in oak, pine, and fir—were essential for fueling colonial infrastructure projects like railways and shipbuilding for the Royal Navy. Strategically, the acquisition secured British influence along the sensitive Sikkim-Nepal border, facilitating administrative oversight and military positioning in the eastern Himalayas amid ongoing territorial negotiations. The area was subsequently notified as a reserve forest under the Indian Forest Act of 1878, marking the onset of systematic resource extraction.[5]By the early 20th century, the Singalila Ridge gained prominence as a key access route for mountaineering expeditions targeting Kangchenjunga. The 1905 Anglo-Swiss attempt, led by Jules Jacot-Guillarmod with Aleister Crowley as a key member, approached the mountain's southwest face via the Singalila Ridge from Darjeeling, passing through high passes like Sandakphu and Phalut before descending to the Yalung Glacier base camp. This traverse, covering rugged terrain at elevations over 3,600 meters, underscored the ridge's logistical importance for early Himalayan climbs, despite the expedition's failure to summit due to avalanches and harsh weather. Such ventures highlighted Singalila's role in pioneering high-altitude exploration prior to formalized protections.[6]
Establishment as Protected Area
Following India's independence, the West Bengal Forest Department undertook post-independence surveys and boundary delineations in the Singalila region to assess its ecological significance and facilitate formal protection.[7] These efforts built upon the area's earlier designation as a reserve forest, acquired by the British Government from the Sikkim Durbar in 1882.[3]In 1986, the Government of West Bengal declared Singalila a wildlife sanctuary under Section 18 of the Wildlife (Protection) Act, 1972, to conserve its unique high-altitude ecosystems and biodiversity.[8] This initial protected status covered the core forested ridges along the Singalila range, emphasizing habitat preservation amid growing environmental concerns in the eastern Himalayas.[1]The sanctuary was upgraded to national park status in 1992 under Section 35 of the same Act, expanding its protected coverage to 78.6 km² and granting it higher administrative priority for long-term conservation.[8] This elevation reflected the West Bengal Forest Department's ongoing delineation work, which precisely mapped the park's boundaries to include key alpine meadows and ridgelines while excluding adjacent human settlements.[1]
Geography
Location and Boundaries
Singalila National Park is situated on the Singalila Ridge in the Darjeeling district of West Bengal, India, with central coordinates approximately at 27°07′N 88°04′E.[9] This positioning places the park within the rugged terrain of the Eastern Himalayas, serving as a critical link in the region's transboundary landscapes.[10]The park's boundaries extend along international and state lines, bordering Sikkim to the north and Nepal to the west, which underscores its role in cross-border conservation efforts.[10] It forms part of the Eastern Himalayan biodiversity hotspot, one of the world's most ecologically significant regions characterized by exceptional species richness and endemism.[11] Key peaks such as Sandakphu, the highest point in West Bengal, lie within or adjacent to its limits, influencing the park's overall spatial configuration.[1]Covering a total area of 78.6 km², the park encompasses elevations ranging from 2,400 m to 3,636 m, creating a compact yet vertically diverse protected zone.[12][13] This altitudinal span highlights the park's compact footprint while emphasizing its integration into the broader Himalayan ecological corridor.[1]
Topography and Hydrology
Singalila National Park is situated in the Eastern Himalayas, characterized by the prominent Singalila Ridge that runs roughly north to south, forming a natural divide between the Himalayan regions of West Bengal and neighboring ranges.[1] This ridge features steep slopes and undulating terrain, with elevations ranging dramatically from lower valleys to high-altitude plateaus, creating a rugged landscape ideal for trekking routes. The topography is dominated by narrow paths along the crest, flanked by dense forests and alpine meadows that transition into subalpine scrub at higher elevations.[1]The park's highest points are Sandakphu, at 3,636 meters, the tallest peak in West Bengal, and nearby Phalut, rising to 3,600 meters, both located along the Singalila Ridge.[1] These summits provide panoramic vistas of the Kangchenjunga massif and the Everest range, including Mount Everest itself, offering unobstructed sights of snow-capped peaks on clear days.[1] The steep inclines and ridge systems around these peaks contribute to the park's isolation and ecological diversity, with trails like the Sandakphu-Phalut route traversing these elevated features.[1]Hydrologically, the park is nourished by two major rivers, the Rammam and the Srikhola (also spelled Sirikhola), both originating within the Singalila Range and flowing southward through the park's valleys before joining larger river systems.[1] The Rammam River emerges from high-altitude sources in the range, carving through forested gorges and supporting riparian habitats along its course. Similarly, the Srikhola River drains the eastern flanks, meandering through the park and fostering wetlands and streams that sustain the local biodiversity.[1] These waterways are vital for the park's ecosystem, though their steep gradients lead to seasonal variations in flow.[1]
Climate and Ecology
Climate Patterns
Singalila National Park experiences a subtropical highlandclimate characterized by cool temperatures, high humidity, and significant monsoon influences due to its location in the Eastern Himalayas at elevations ranging from 2,300 to 3,636 meters. This climate classification aligns with the Köppen system as Cwb, featuring mild summers, cold winters, and no extreme heat, moderated by the surrounding mountain ridges that trap moisture from the Bay of Bengal.[1]The park receives an average annual rainfall of approximately 2,500–3,000 mm, with the majority—about 80%—occurring during the southwest monsoon season from June to September, leading to lush vegetation growth but also increased risks of landslides and flooding. Winter temperatures (December to February) typically range from 5°C to 15°C, with occasional frost at higher elevations, while summer (March to May) sees highs of 20–25°C during the day, dropping to 10–15°C at night. These patterns are influenced by the park's altitude, which contributes to cooler conditions compared to lower Himalayan foothills. Recent climate trends as of 2025 indicate shifting monsoon patterns and more frequent extreme rainfall events, exacerbating landslide risks in the region.[14][15]Due to the intense monsoon downpours, the park is officially closed to visitors from June 16 to September 15 each year to ensure safety amid heavy rains and potential landslides, as mandated by the West Bengal Forest Department.[16]
Biomes and Habitats
Singalila National Park exhibits a pronounced elevational gradient that drives distinct biome transitions, reflecting the broader patterns of the Eastern Himalayan ecoregion. The lower elevations, starting from approximately 2,300 meters above sea level, feature temperate broadleaf forests characterized by dense, humid woodlands adapted to cooler, wetter conditions influenced by monsoon inflows. As altitude increases to 2,300–3,000 meters, these are dominated by mixed deciduous and evergreen canopies that thrive in mist-laden environments.[1][17]Above 3,000 meters, the landscape shifts to subalpine coniferous zones, where conifer-dominated stands interspersed with broadleaf elements form resilient ecosystems against harsher winds and lower temperatures. These upper zones include cloud forests, where persistent fog and high humidity create unique microhabitats supporting epiphytic growth and specialized moisture-retaining structures. At the highest elevations, exceeding 3,400 meters, alpine meadows emerge, consisting of open herbaceous grasslands and shrublands that mark the treeline and provide seasonal foraging grounds amid rocky outcrops. Climatic drivers, such as decreasing temperatures and increasing precipitation variability with elevation, facilitate these biome shifts.[1][17][18]This role underscores the area's contribution to regional climate regulation through its diverse ecosystems.
Biodiversity
Flora
Singalila National Park hosts a rich diversity of plant life, characteristic of the Eastern Himalayan temperate and sub-alpine forests. The park's vegetation is stratified by elevation, with lower slopes featuring mixed broadleaf forests transitioning to coniferous and shrub-dominated zones at higher altitudes.[19]The cloud forests of the park are renowned for their orchid diversity, with rare and endemic varieties from the Singalila Ridge preserved at the nearby Lloyd's Botanical Garden in Darjeeling, where collections linked to park surveys highlight species such as Paphiopedilum and other epiphytic orchids adapted to the misty, high-humidity environment.[20][21]Dominant tree species include oaks (Quercus spp., such as Quercus leucotrichophora), magnolias (Magnolia campbellii), and extensive rhododendron forests comprising over 30 species, including 18 of the 25 discovered by Sir Joseph Dalton Hooker in the Himalayas. These rhododendrons, such as Rhododendron arboreum and Rhododendron grande, form thickets that color the landscape during spring blooms. Bamboo thickets, particularly Yushania maling, are prevalent in understory layers, providing structural support to the forest ecosystem.[22][19]Among the park's flora, several medicinal plants hold traditional significance, including the Himalayan yew (Taxus wallichiana), valued for its bark and leaves in treating ailments like coughs and fevers, and high-altitude herbs such as Gaultheria spp. used by local communities for their anti-inflammatory properties. These species underscore the park's role in ethnobotanical heritage.[21][23]
Fauna
Singalila National Park supports a diverse array of fauna adapted to its high-altitude Himalayan ecosystems, with mammals, birds, and limited reptiles and amphibians inhabiting the temperate forests and alpine meadows.[1] The park's fauna is characteristic of the Eastern Himalayan biodiversity hotspot, where species exhibit preferences for rhododendron-dominated understories and bamboo thickets at elevations ranging from 2,300 to 3,636 meters.[1]Among mammals, the park is particularly noted for its populations of elusive carnivores and herbivores. The red panda (Ailurus fulgens), classified as Endangered by the IUCN, maintains a resident population estimated at least 38 individuals based on genetic analysis of scat samples conducted around 2012, with ongoing surveys confirming its presence in bamboo-rich habitats.[24] Other notable mammals include the Himalayan black bear (Ursus thibetanus), which forages across forested slopes, the clouded leopard (Neofelis nebulosa), a rare apex predator sighted occasionally in dense cover, and the barking deer (Muntiacus vaginalis), a common ungulate that inhabits lower elevation woodlands.[1]The avifauna of Singalila is rich, with over 400 species recorded, including more than 120 endemics to the Himalayan and Indo-Burma regions that utilize the park as a migratory corridor.[3][25] Prominent pheasants include the satyr tragopan (Tragopan satyra), known for its vibrant plumage and ground-dwelling habits in rhododendron forests, the blood pheasant (Ithaginis cruentus), which thrives in alpine scrub, and the Himalayan monal (Lophophorus impejanus), the national bird of Nepal, often observed displaying in open meadows at higher altitudes.[25]Reptiles and amphibians are sparse in the park due to its predominantly high-elevation terrain above 2,300 meters, where cold temperatures limit diversity. However, the Near Threatened Himalayan newt (Tylototriton verrucosus), an amphibian adapted to montane wetlands, congregates around nearby lakes such as Jore Pokhri and Sukhia Pokhri, with occasional records extending into park boundaries; high-altitude frog species, such as those in the genus Nanorana, also occur in moist alpine zones.[1]
Conservation
Efforts and Initiatives
The red panda reintroduction project in Singalila National Park, initiated in 2003 by the Padmaja Naidu Himalayan Zoological Park in collaboration with the West Bengal Forest Department, marked a significant conservation effort for this endangered species. Two female red pandas, named Sweetie and Minnie, were released into the wild, with Sweetie successfully adapting and giving birth to a cub in July 2004 in an oak tree hollow at Gairibas, representing the first such breeding success for a reintroduced individual. Ongoing monitoring, including radio-collaring of subsequent releases—such as four pandas in 2022 and three females in 2023—has confirmed survival rates, habitat use, and further breeding, with five cubs born in 2023, demonstrating the project's long-term viability. The program continued with the release of two additional females in February 2024, and as of 2024, it has gained international recognition for its breeding, rewilding, and genetic preservation efforts. A red panda census is planned for February-March 2025 in Singalila and Neora Valley National Parks.[26][1][27][28]The West Bengal Forest Department has promoted community-based eco-tourism programs to foster local involvement in conservation and curb poaching pressures. These initiatives, managed through the West Bengal Forest Development Corporation, include operating trekkers' huts and guided nature experiences that provide alternative income sources for nearby villages, encouraging community vigilance against illegal activities. Local residents have actively participated in forest protection, assisting forest staff in apprehending poachers and safeguarding habitats, which has strengthened anti-poaching efforts across the park.[29]Post-2010 biodiversity surveys have been instrumental in assessing and guiding habitatrestoration in Singalila National Park. Studies conducted since 2018 have documented forest community compositions influenced by altitude and climate, while 2023 surveys analyzed soil nematode diversity across natural vegetations, informing targeted restoration strategies. Additionally, efforts to enhance fire prevention infrastructure, such as establishing fire protection lines and management protocols, have been integrated into broader habitat recovery plans to mitigate wildfire risks and preserve ecological integrity.[17][30][31]
Threats and Challenges
Singalila National Park faces significant risks from forest fires, particularly during dry seasons when vegetation becomes highly combustible. A major fire on 6 March 2006 affected nearly 75 hectares in the park's higher reaches, destroying critical habitats and exacerbating soil erosion in this fragile alpineecosystem.[32] Ongoing fire risks persist due to seasonal dryness and human-induced ignitions, threatening the park's biodiversity hotspots.[1]Human activities pose additional pressures through illegal grazing, tourism-related waste accumulation, and poaching. Livestock grazing by local communities encroaches on forest areas, leading to overgrazing that degrades understory vegetation and increases soil compaction in sensitive meadows.[33]Tourism, while economically vital, contributes to substantial trash buildup along trekking routes, with litter from trekkers, hotels, and eateries—including polythene and plastics—polluting water sources and harming wildlife.[34]Poaching targets species like red pandas and pangolins, driven by illegal wildlife trade, further endangering the park's mammalian diversity.[35]Climate change amplifies these threats through shifting monsoon patterns and habitat fragmentation, as noted in assessments from the 2020s. Altered rainfall regimes disrupt flowering cycles and water availability, while warming temperatures contribute to the isolation of high-altitude habitats, limiting species migration and genetic exchange in the Eastern Himalayas.[36][37] These changes particularly affect vulnerable species such as red pandas, whose bamboo-dependent habitats are increasingly fragmented.[35]
Visitor Information
Activities and Trekking
Singalila National Park offers a range of recreational activities centered on its pristine trekking trails and opportunities for wildlife observation, all designed to promote sustainable tourism within its high-altitude ecosystems. The park's primary attraction is the renowned Sandakphu-Phalut trek, recognized as the longest route within the protected area, spanning approximately 53 kilometers and typically undertaken over 4 to 5 days. This trek begins at Manebhanjan, a base village at an elevation of about 2,150 meters, and ascends through diverse terrains including rhododendron forests, alpine meadows, and ridgelines, culminating at Sandakphu (3,636 meters), West Bengal's highest point, before extending to Phalut (3,600 meters) for panoramic views of the Himalayan giants like Everest, Kanchenjunga, and Makalu.[38] The initial 32-kilometer segment to Sandakphu involves moderate ascents and can be covered in 2 to 3 days, with the additional 21-kilometer extension to Phalut being relatively easier and adding one more day, allowing trekkers to traverse the Singalila Ridge while encountering varied flora and fauna.[38][39]Beyond trekking, the park is a prime destination for birdwatching and nature photography, hosting over 500 bird species, including the Himalayan monal, blood pheasant, and satyr tragopan, amid its oak, bamboo, and conifer habitats. Optimal periods for these activities are spring (March to May), when rhododendron blooms attract nectar-feeding birds, and autumn (September to December), during migration seasons that enhance sightings of raptors and passerines.[40][41] Key spots include the trails around Tumling and Gurdum for close-up photography of elusive species, with the clear skies and mild weather facilitating long-distance shots of the surrounding peaks.[42]Access to all activities requires permits issued by the West Bengal Forest Department through local offices, such as the one at Manebhanjan, with fees set at ₹100 per day for Indian citizens and ₹200 for foreigners (as of 2025), plus vehicle entry at ₹400.[43][42] Hiring a local guide is mandatory to ensure safety on high-altitude paths and adherence to eco-guidelines, which emphasize staying on designated trails, avoiding single-use plastics, and minimizing noise to protect sensitive wildlife habitats.[40] These measures, promoted by the West Bengal Tourism Department, help sustain the park's biodiversity while allowing visitors to engage responsibly.[44] The park implements seasonal closures during the monsoon (June 16 to September 15) due to landslides and heavy rains, as well as winter periods of intense snowfall.[40]
Accommodations and Facilities
Singalila National Park provides a range of basic accommodations primarily through guest houses and trekkers' huts operated by the Gorkhaland Territorial Administration (GTA), catering to visitors undertaking treks in the area. These facilities are situated at strategic locations including Tonglu, Gairibans, Sandakphu, and Phalut, offering dormitory-style rooms with essential amenities such as bedding and shared common areas suitable for budget-conscious travelers.[1][40]Bookings for these GTA-managed huts are typically arranged through the Maneybhanjan forest office or the GTA tourism department's portal, ensuring availability for individual beds or rooms in advance, especially during peak seasons. The huts feature simple infrastructure, including attached or shared toilets in some cases, and on-site restaurants serving basic meals.[45][46]Private accommodation options complement the official facilities, with eco-friendly stays like the Sailung Tea House at Meghma providing cozy, independent lodging amid scenic views, and other homestays or lodges in nearby villages such as Rimbick offering more personalized experiences with added comforts.[1][47]In response to growing tourism since around 2020, infrastructural developments have enhanced support facilities within the park, including better waste management and energy provisions to promote sustainability, though challenges like limited electricity persist in remote huts.[48]
Access and Transportation
Singalila National Park is primarily accessed via the town of Manebhanjan, the main entry point located at the southern edge of the park, from where visitors can proceed to key areas like Tumling and further into the ridges.[49] The park's remote Himalayan location necessitates road travel from major transport hubs in West Bengal, with no direct public bus services to the interior.[42]The nearest airport is Bagdogra Airport (IXB) near Siliguri, approximately 90 kilometers from Manebhanjan, reachable in 3 to 4 hours by taxi or shared jeep along winding mountain roads via Mirik.[50] From the airport, pre-arranged pickups are recommended, as direct prepaid taxis to Manebhanjan are unavailable, and the route involves steep ascents unsuitable for standard vehicles.[49]For rail access, the primary station is New Jalpaiguri Junction (NJP) in Siliguri, about 80 kilometers from Manebhanjan, followed by a 4 to 5-hour drive.[51] Alternatively, Ghoom Railway Station on the Darjeeling Himalayan Railway (toy train) is closer at 31 kilometers from the Tonglu trailhead, an entry point for northern sections, though it requires additional road transfer from Darjeeling town, 26 kilometers away (1 hour 15 minutes by taxi).[49]Road connectivity relies on shared jeeps from Siliguri or NJP to Manebhanjan, covering around 90 kilometers in 4.5 hours for about Rs. 250–300 per person; these sturdy vehicles navigate the hilly terrain effectively.[49] Once at Manebhanjan, vintage 4WD Land Rovers or similar jeeps provide internal transport along gravel ridges to destinations like Sandakphu (30 kilometers, 2.5 hours) and Phalut, with developments enhancing road accessibility since the mid-2010s allowing for more reliable jeep safaris.[52] Visitors must obtain an entry permit from the forest department office at Manebhanjan prior to proceeding, costing Rs. 100 for Indians and Rs. 200 for foreigners per day (as of 2025).[43]
Cultural and Media Aspects
Human Presence
Singalila National Park features limited human habitation, with no permanent settlements within its core interior to preserve its ecological integrity. Small villages, such as Manebhanjan and Kala Pokhri, are situated along the park's periphery and trekking routes, serving as entry points for visitors and locals. These settlements are primarily inhabited by indigenous groups including Sherpa, Rai, Tamang, and Chettri communities, who maintain traditional lifestyles in the surrounding Darjeeling district.[1][53] Lepcha communities, recognized as original inhabitants of the broader Himalayan region encompassing Darjeeling, also reside in nearby areas like Lepchajagat, contributing to the cultural mosaic without encroaching on the park's boundaries.[54]Indigenous communities in the fringe villages engage in traditional resource uses that have shaped their interaction with the park's ecosystems for generations. Grazing of livestock, though officially restricted since 2010 in adjacent Sikkim areas, persists on a limited scale, with most households practicing stall-feeding to minimize environmental impact. Herbal collection remains a vital activity, focusing on medicinal plants such as Yushania maling for traditional remedies and wild edibles, reflecting sustainable practices amid resource pressures. These uses are integral to the livelihoods of Sherpa and related groups in villages like Gorkhey-Samanden and Ribdi-Bhareng, where forest resources support about 80% of stall-fed animal needs.[53][55]The park holds cultural significance in local folklore, particularly among Lepcha and Sherpa communities, who view the Singalila Ridge as part of a sacred Himalayan landscape inhabited by deities and spirits. Lepcha traditions emphasize nature worship, with myths linking clans to mountains, rivers, and forests, portraying the Himalayas as abodes of benevolent and protective entities that guide human endeavors. This reverence extends to expeditions and treks, seen not merely as physical journeys but as spiritual quests to honor these deities, fostering a deep-seated conservation ethic among indigenous groups.[54][56]
Films and Documentaries
One of the most notable documentaries centered on Singalila National Park is Cherub of the Mist (2005), directed by Ajay and Vijay Bedi of Bedi Films. The film chronicles the reintroduction of two captive-bred red pandas, named Mini and Sweety, into the park's misty Himalayan forests, capturing their adaptation, courtship, mating, and the birth of their cubs in the wild for the first time on camera. It emphasizes the challenges of conserving this endangered species in its natural habitat along the Indo-Nepal border.[57][58]The documentary received critical acclaim, including the Best Film on Conservation & Environment award at the 29th International Wildlife Film Festival in Missoula, Montana, held from May 13-20, 2006. This recognition highlighted its contribution to raising awareness about red panda conservation efforts in the Eastern Himalayas.[58]While no major feature films have been produced about the park, Singalila has appeared in various trekking-focused documentaries, particularly those showcasing the scenic Sandakphu-Phalut route. For instance, recent 2020s travel series on platforms like YouTube feature the park's high-altitude trails, rhododendron forests, and panoramic views of Himalayan peaks, attracting adventure enthusiasts. Examples include episodes from channels documenting multi-day treks starting from Manebhanjan, emphasizing the route's biodiversity and cultural waypoints.[59]Additionally, the park has been included in short clips within Indian wildlife series post-2010, often highlighting its role in red panda habitats and avian diversity. Productions like Roundglass's The Misty Mountains of Singalila: Eastern Himalayas (2023) explore the park's unique ecosystems, including its elusive mammals and bird species, as part of broader narratives on India's high-altitude biodiversity.[60]