234 



NOTES ON THE BIRDS OF UPPER ASSAM. 



By 

 H. Stevens, m.b.o.u. 



Part I. 



Upper Assam politically comprises the subdivisions of Lakhim- 

 ptir* and Dibrugarh in the Lakhimpnr district, practically the 

 tract of country lying north of the 27th parallel of north 

 latitude encroaching on the adjacent district of Sibsagar and 

 limited by the indefinite arbitrary frontier line of British juris- 

 diction which follows the contour of the hills at their base 

 around the head of the valley ; but considered from our stand- 

 point of Zoo — Geographical Distribution as a northern area of 

 the Oriental Region enclosing portions of the Himalayan and 

 Burmese subregions would include several of these hill ranges. 

 Our knowledge of the hill districts with the exception of the south- 

 eastern ranges however is very imperfect, and so far as the north 

 and north-eastern frontier is concerned almost a complete blank due 

 to several causes. The natural inhospitality and impenetrability of 

 their forest-covered slopes, the suspicious hospitality of the 

 various tribes, the stringent restrictions issiied by an administra- 

 tion averse to any transfrontier excursions, and also the lack 

 of means of communication, combined with the tropical rains 

 experienced during the south-west monsoon, irrespective of a 

 considerable local rainfall, which renders the routes traversed impass- 

 able and restricts a journey of that description to the cold season 

 when such an undertaking can only be attempted. The numerous 

 waterways constitute the main physical features of the valley, fore- 

 most of which is the Bramapootra with its main affluents, the 

 Subansiri and the Dihing, other minor rivers emerge through, 

 picturesque and impressive gorges in the hills on the north and 

 add their quota to its waters. During the period of torrential rains 

 a large proportion of the land is submerged. The appearance of the 

 country at this time is a striking contrast to its cold season aspect 

 when the rivers are at a low ebb and exhibit vast expanses of sand. 

 The diversified vegetation compensates somewhat for the monoton- 

 ous level of the alluvial land and the hills which rise in rapid 

 succession on the northern frontier clothed to their summits in 

 virgin forest and backed by the snow-capped peaks of higher 

 elevations afford a pleasing panorama during the cold weather 

 months when the atmosphere is free from humidity. The deforest- 

 ation and the opening up of large areas of land by the tea industry 

 has been in progress many years ; each succeeding year also results 



• The Post Office designation, North Lakhimpur, is invariably used for this 

 subdivision. 



