Exploring the Avian Diversity of Samtse: Untapped Habitats and Rich Ornithological History

The diverse habitats in Samtse, ranging from the hot hills of Kalisor Plain in Tading (bordering Totapara, West Bengal, India) at 160 meters above sea level to the cold mountain peaks of Doklam Trijunction over 4,200 meters above sea level, contribute to its remarkable avifaunal diversity. This district, covering approximately 1,309 square kilometers, hosts an impressive variety of birds, including 14 globally threatened species. The area between these extremes, featuring searing riverbanks and dense jungles, is home to 419 bird species recorded up to date. Thus, Samtse is a significant reservoir of avian species in Bhutan.

Samtse shares its border with the Indian states of West Bengal to the south and Sikkim to the west. The region experiences hot summers, with temperatures reaching up to 40°C, and heavy rainfall during the monsoon season, particularly in July and August. However, the winter and autumn seasons are ideal for visiting, with temperatures ranging from 15°C to 28°C. Samtse encompasses a variety of habitats, including riverine shrubs, riverbanks, grasslands, paddy fields, fishery ponds, rivers with gravel banks, arable lands, townships, warm broadleaf forests, gardens, bamboo forests, streams, and villages. However, some areas, such as Nimaling, Halalay, and Damdum top, remain relatively unexplored due to rugged terrains and rocky cliffs.

R.B. Pemberton, a political missionary, began documenting the birds of Bhutan as early as 1838 (Clements, 1992). Since then, numerous Western naturalists, including F. Ludlow and G. Sherriff (1937), Salim Ali, B. Biswas, and S.D. Ripley (1966 & 1973), Gaston (1989), and F.A. Clements (1986 & 1990), have visited Bhutan to study its birds, plants, and flowers. Among them, F. Ludlow was the first ornithologist to conduct an intensive study of Bhutan's avifauna. In 1928, F. Ludlow and G. Sherriff met the second King of Bhutan, His Majesty Jigme Wangchuck, a year after his ascension to the throne in 1927. His Majesty granted them unrestricted travel throughout the country to study its birds and plants. Their first trip occurred in 1933, followed by a second in 1934. The 1933 journey to East Bhutan left a significant impression on them, offering promising opportunities for further investigation. Consequently, the 1934 expedition was planned to revisit their previous study sites in the Trashiyangtse valleys.

Over three decades later, in 1966, the third King of Bhutan, His Majesty Druk Gyalpo Jigme Dorji Wangchuck, initiated a research program to survey Bhutan's birds, aiming to create a comprehensive and illustrated field guide for his guests. To achieve this, His Majesty invited ornithologists from the Zoological Survey of India (ZSI) to discuss the research. A team from ZSI, including Dr. Salim Ali, Dr. Biswamoy Biswas, and Dr. S. Dillon Ripley, conducted a survey of Bhutan's avifauna. Between February 1966 and December 1973, they collected 3,218 specimens of 481 species. From November 22-27, 1968, they surveyed the riverbanks of the Amo Chhu and surrounding areas, including Samtse, recording 46 species and collecting 340 specimens.

While exploring the status and distribution of the Black-necked Crane (Grus nigricollis) in the east and the White-bellied Heron (Ardea insignis) in the west, the ornithologists left the avifauna of the south relatively unexplored. However, some studies on the southern avifauna were conducted by Ludlow & Sherriff (1937), the Zoological Survey of India (2002), P. Spierenburg (2005), Feijen & Feijen (2008), Tobgay (2018), Passang (2018), Grimmet, Inskipp, Inskipp, & Sherub (2019), Birds of Bhutan (Bhutan BirdLife Society) (2019), and Wangdi & Tshering (2020). The book "A Guide to the Birds of Samtse" documented 371 species over six years (Wangdi & Tshering, 2020). Passang (2018) studied the diversity of waterbirds along the Bindu river in Samtse, recording 296 individuals from 12 species.

Additionally, travel restrictions on international tourists in Samtse have rendered it one of the least explored, if not entirely untapped, locations. Avid birders in Samtse discovered the Indian Pitta (Pitta brachyura) in May 2019 (Tshering, 2019) and the Zitting Cisticola (also known as the Streaked-fantail Warbler) (Cisticola juncidis) in December 2019 (Tamang, 2019). The second recorded sighting of the Golden-crested Myna (Ampeliceps coronatus) in Samtse occurred in August 2019 (Tshering, 2019). Consequently, Samtse remains a promising location for exploring avian species.