THE BIRDS AND MAMMALS OF IMAW BUM. 7o7 



With the exception of the Takin I shall not say anything about the larger 

 mammals of Imaw Bum, for the reason that they are well known. The Hima- 

 layan bear must be quite common, though I did not come across it. Two skins 

 were brought to me by the Lisus, one of very large size ; and two live cubs. 

 There is also a small brown tree bear. 



The barking deer was often heard in the deep valley of the Ngawchanghka, 

 also gibbons. On one occasion the skin of a flying fox was brought to me, but 

 I never saw that animal, and only a few times did I see bats. Squirrels were 

 fairly common between 5,000 and 8,000 feet. I secured three or four, belonging 

 to two distinct species, all shot by the Lisus with cross-bow and bamboo arrow ; 

 they also distinguish them, calling the larger hihl, the smaller hape. 



In 1914 I sent to the Natural History Museum several specimens from the 

 North-East Frontier, including a shrew {Blarinella ivardii, Thomas), A water- 

 shrew {Chimarogale styani — the second known example), several voles, and 

 a h arvest mouse. 



In 1919 I collected some more specimens, including voles, shrews, long-tailed 

 mice, bamboo rats. Pica hare and others. I found the region of bamboo and 

 Rhododendren forest, at about 9,000 feet altitude to be the richest in ground 

 mammals. Through this forest Conifers are also scattered, and there are open 

 meadows in places along the crests of the ridges. Here indeed, throughout the 

 summer at least, little animals swarmed in such numbers that it is evident they 

 must play an important role in nature. When camped in this belt, with three 

 traps I always caught at least one mammal, and this without stirring above a 

 hundred yards from my tent. The steep slopes beneath the bamboo clumps 

 and under the Rhododendren and other trees were honeycombed. Here I 

 caught chiefly voles and long-tailed mice, also a pigmy hare and a shrew, both 

 taken by day. Indeed the shrews seem to be diurnal rather than nocturnal in 

 their habits, probably because their food is abroad by day. I caught two also 

 running about inside my tent, both in the day time ; they moved in sudden little 

 darts, their long noses glued to the ground, poking under leaves and sticks. 

 They all seemed to be blind and rather deaf, and even their sense of scent seemed 

 at fault, at least so far as I was concerned, for they made no serious effort to 

 escape my clutches. 



In the same way the Pica hares are diurnal. On the grass hills of south-eastern 

 Tibet the ground is riddled with their burrows, ana' I saw them scampering about, 

 popping in and out of their holes like rabits. Chimarrogale too may be a day- 

 light animal ; the only one I caught was taken by hand in a stream during the 

 day time at 11,000 feet altitude. But the voles and mice are certainly not 

 nocturnal nor is it obvious why they should be. It must be harder for them to 

 find their food in the dark, and as they have nothing to fear from man in 

 these lonely forests, it must be something else they hide fi'om. Birds of prey are 

 rare at these altitudes, but weasels are more common. 



Having found the 9,000 feet belt prohfic in small mammals during the heavy 

 rains of June, I tried 1,500 feet higher in July. Camp was pitched on a narrow 

 granite ridge, in a forest of bamboo. Rhododendron arizelum and Abies sp. On 

 either side the ridge sloped very steeply, and beneath the almost horizontal 

 stems of the outgrowing Rhododendrons, mammal burrows were extraordinarily 

 plentiful. Yet in six nights, using three traps a night, I did not catch a single 

 mammal here. Either (j) the original inhabitants of the holes had temporarily 

 abandoned this altitude at this particular season for lower or higher altitudes ; 

 or{ii) the area had been worked out for good and permanently deserted as fallow, 

 the mam.ijials migrating. I could think of no other possible explanation to 

 account for the absence of mammals from a place where they had obviously once 

 Uved in thousands. The weather was extremely wet during six days I remained, 

 in camp here, but we had two fine nights. Moreover, it was just as wet lower 

 down, and the mammals came out at night just the same wet or fine. 



