Rema-Kalenga

Rema-Kalenga Wildlife Sanctuary is one of Bangladesh's most biologically significant protected areas, located in Habiganj District of the Sylhet division in the northeastern part of the country. Covering approximately 1,796 hectares (4,437 acres), it is the country's second-largest wildlife sanctuary and is considered the second-largest natural forest in Bangladesh after the Sundarbans. The sanctuary protects a tract of tropical evergreen to semi-evergreen hill forest that represents some of the last remaining natural forest in the mixed hill landscape of northeastern Bangladesh. It was formally designated as a wildlife sanctuary in 1996. The sanctuary is situated in a region where the flat agricultural plains of the Sylhet basin meet the forested hills of the Tripura border area, creating a diverse landscape of forest types and ecological niches. The Bangladesh Forest Department administers Rema-Kalenga, which is recognised as a priority conservation site for globally threatened forest species.

Rema-Kalenga Wildlife Sanctuary supports one of the highest concentrations of threatened and endemic wildlife in Bangladesh, with surveys recording 37 mammal species, 167 bird species, 18 reptile species, and 7 amphibian species. The sanctuary is particularly important for primate conservation, hosting endangered western hoolock gibbon, capped langur, Phayre's leaf monkey, northern pig-tailed macaque, Assamese macaque, and Bengal slow loris. Critically endangered white-rumped vulture maintains a breeding colony within the sanctuary, one of the very few remaining in Bangladesh. Asian black bear, binturong, yellow-throated marten, and clouded leopard have been recorded among the carnivore community. The forest's bird diversity includes diverse raptors, hornbills, babblers, and migratory species from the broader Oriental biogeographic region. The sanctuary's value as one of the last intact forest blocks in northeastern Bangladesh makes it a critical refuge for species that have been extirpated from most of the surrounding landscape.

Rema-Kalenga Wildlife Sanctuary supports a rich and diverse forest flora, with over 634 plant species recorded within its boundaries. The forest is classified as tropical evergreen to semi-evergreen, characteristic of the hill forest zone of northeastern Bangladesh and adjacent parts of India and Myanmar. The canopy is composed of diverse broadleaf tree species that form a dense cover shading the forest interior. Bamboo of multiple species is abundant in disturbed areas and along forest margins, providing food and cover for various wildlife. The sanctuary's understory and ground layer support a rich flora of shrubs, ferns, orchids, and climbing plants. Riparian vegetation along streams within the sanctuary contributes additional biodiversity. The high plant species richness of Rema-Kalenga reflects the sanctuary's position in a transition zone between the Indo-Gangetic plain and the Sino-Himalayan flora, where species from both biogeographic regions can be found. The intact forest canopy is critical for the primate species that depend on forest connectivity and large home ranges.

Rema-Kalenga Wildlife Sanctuary lies within the northeastern hill zone of Bangladesh, a region of low to moderate hills formed by the outermost folds of the Indo-Burman Ranges as they extend westward from the Chittagong Hill Tracts into the Sylhet and Habiganj districts. The hills are composed of sedimentary rocks, primarily sandstone and shale of Tertiary age, that have been folded and eroded into the rounded ridges and valleys characteristic of the landscape. The terrain is more subdued than the higher Chittagong Hills to the south, with elevations reaching several hundred metres in places. Soils derived from the weathered sedimentary rocks support the tropical forest that covers the sanctuary, though they are vulnerable to erosion where forest cover is removed on steep slopes. The network of streams draining the sanctuary hills flows into rivers of the Surma-Meghna system, contributing to the hydrology of the broader Sylhet basin. The forested hills provide important watershed protection functions for agricultural areas downstream.

Rema-Kalenga Wildlife Sanctuary experiences a humid subtropical to tropical monsoon climate, with a pronounced wet season driven by the southwest monsoon and a cooler, drier winter. The Sylhet region of northeastern Bangladesh receives very high rainfall, typically exceeding 3,000 millimetres (118 inches) annually, as moist air masses from the Bay of Bengal are enhanced by orographic effects as they encounter the hills of northeastern India and the Meghalaya plateau. The monsoon season from May to October brings heavy rainfall that saturates the forest soils and swells streams within the sanctuary. Temperatures are warm throughout the year, with the hottest period in April and May and the coolest months from December to February, when nighttime temperatures can fall noticeably in the forested hills. The high rainfall and humidity support the lush evergreen forest cover that characterises the sanctuary. The winter months offer the most comfortable conditions for trekking and wildlife observation, with reduced rainfall and moderate temperatures.

The hill forest landscape in which Rema-Kalenga Wildlife Sanctuary is located has historically been home to indigenous communities including the Tripuri and other groups who have maintained traditional relationships with the forest over many generations. The broader Habiganj and Sylhet region was incorporated into the Bengal Presidency during the British colonial period, and the tea plantation industry established in the nineteenth century transformed much of the surrounding lowland and hill landscape, bringing large numbers of labourers from other parts of India. The forest of Rema-Kalenga was historically used by local communities for timber, fuelwood, bamboo, and other forest products, and encroachment into forest land for agriculture has reduced the extent of natural forest throughout the region. The proximity of the sanctuary to the international border with Tripura State in India has influenced its history and continues to pose management challenges related to cross-border hunting and movement of wildlife.

Rema-Kalenga Wildlife Sanctuary was formally designated in 1996 under Bangladesh's wildlife protection legislation, recognising the exceptional biodiversity value of this remnant hill forest tract in the Sylhet region. Prior to formal designation, the forest had status as a reserved forest under the Bangladesh Forest Department. The sanctuary has been a focus of biodiversity research and conservation investment, with international organisations including the International Union for Conservation of Nature supporting surveys, management planning, and community outreach programmes. The discovery of a breeding colony of critically endangered white-rumped vulture in the sanctuary brought additional conservation attention. The sanctuary has been selected as one of the priority sites for conservation action under Bangladesh's protected area system strengthening programmes. Eco-guide training programmes have been established to develop community-based ecotourism that provides income for local people while reducing pressure on forest resources.

Rema-Kalenga Wildlife Sanctuary is a rewarding destination for ecotourism, trekking, and wildlife watching, with a network of forest trails penetrating the hilly interior. The sanctuary is particularly popular with birdwatchers, who come to seek the diverse forest bird community including hornbills, raptors, babblers, and the rare white-rumped vulture. Primate watching, particularly for hoolock gibbon and various langur species, is another major draw, and gibbons are often heard calling in the early morning. The forested hills provide scenic landscape for hiking and nature photography. Local eco-guides trained by conservation organisations can be hired to lead visitors through the forest and enhance wildlife spotting success. The sanctuary can be reached from Habiganj town, and access points for trekking are established at several locations around the forest boundary. The cool season from November to March is the best period for visiting, when wildlife activity is high and trekking conditions are most comfortable.

Rema-Kalenga Wildlife Sanctuary is accessible from Habiganj District headquarters, which can be reached by road from Sylhet city or directly from Dhaka by road. Local transport from Habiganj town provides access to the sanctuary's main entry points. The sanctuary has a limited tourism infrastructure, but eco-guide services are available and recommended for visitors wishing to maximise wildlife sightings and navigate the forest trails safely. A basic rest house may be available for overnight stays, and there are accommodation options in Habiganj town. The Forest Department maintains a presence at the sanctuary and can provide visitor information. The best time to visit for birdwatching and general wildlife observation is from November to March during the dry season, when trails are more passable and wildlife is easier to observe in the forest. Visitors with a serious interest in primates or birds should plan an early morning start when wildlife activity peaks.

Rema-Kalenga Wildlife Sanctuary faces serious conservation challenges despite its protected status. Forest encroachment by surrounding communities for agriculture and settlement has reduced the effective area of natural forest over time. Illegal logging and collection of bamboo and timber remain ongoing threats. Hunting of wildlife, including primates and deer, has depleted populations of sensitive species. The sanctuary's location near the international border creates additional management challenges related to cross-border hunting and the difficulty of monitoring remote forest areas. The fragmented and isolated nature of the sanctuary in a heavily modified landscape limits the viability of populations of wide-ranging species. Conservation programmes emphasise community engagement, eco-guide training for sustainable livelihoods, and strengthening enforcement capacity. Restoring forest connectivity between Rema-Kalenga and other remaining forest patches in the region is a long-term priority for sustaining viable populations of the sanctuary's globally threatened species.