496 APPENDIX C 



and leaves were found. While setting traps one afternoon 1 saw what 

 might have been one of these rats dart from a deserted bird's-nest and 

 run down a limb to the ground. The following morning 1 caught a 

 masked tree rat in a trap set beneath the nest. 



Four-striped Grass Rat {Arvicanthiis puinilio ininutus). At Naivasha we first 

 came across this species, where it was found on the east side of the lake 

 only, although the spotted rat was common on both the east and the 

 west side. At Naivasha these two animals inhabited slightly different 

 regions. In the brushy and grassy thickets bordering the lake spotted 

 rats were abundant, but a few four-striped rats were captured. As soon 

 as the traps were transferred to thorn-tree groves, where there was 

 plenty of uuder-bushes, and not so much grass and weedSj the spotted 

 rats were found in great numbers, but no four-striped rats. All the way 

 from Fort Hail to Mount Kenia, and as high as 10,700 feet, where 

 Dr. Mearns secured one specimen, this species was common. We also 

 caught them along the route between Kampala aud Butiaba. 



Giant Rat (Thrt/notnys gregoriamis). Along the skirtings of the rivers in the 

 thick weeds, grass, and bushes at Fort Hall signs of these animals were 

 common. There were no well-defined paths. Footprints the size and 

 shape of those made by our rauskrats {Fiber) were found in the mud at 

 the water's edge, and here and there were clusters of grass and weed- 

 stems cut in lengths averaging six inches. In sections wliere the vegeta- 

 tion had been burned were innumerable holes, where some animal had 

 dug about the base of grass- tufts. Their signs did not extend farther 

 than fifty feet from water. While passing through a thicket close to the 

 water, l' started a large rodent, which darted through the grass and 

 plunged into the water. 



Mole-Rat {Tachyoryctes splendens ibeanus). Mounds of earth that these rats 

 had thrown from the mouth of their burrows at the time that the tunnels 

 were made were found as far west as Uljoro O'iNyon River, but none at 

 N'garri Narok River. At our camp on the South Guaso Nyero River a 

 pale, mole-coloured mole rat took this animal's place. Some fifteen miles 

 west of Lake Naivasha mole-rats became common, and on the sandy flats, 

 within five miles of the lake, they were so abundant that our horses 

 broke into their runways nearly every step. Tlieir underground tunnels 

 and the mounds of eartli that were thrown out were similar to those 

 made by the pocket gophers of \Vestern United States. Many were 

 snared by the porters and brought to camp alive. They would crawl 

 about slowly, not attempting to run away, but looking for a hole to enter. 

 After the lapse of a few seconds tliey would begin to dig. In any slight 

 depression they began work ; and when small roots or a tussock of grass 

 intervened, they used their teeth until the obstruction was removed, and 

 then, with the nails of their front feet only, continued digging. As the 

 hole deepened they threw the dirt out between their hind-legs, and with 

 them still farther beyond. After the earth had accumulated so that it 

 drifted back, they faced about, and, using their chest as a scoop, pushed 

 it entirely out of the way. They were most active in the evening, at 

 night, and in early morning. Several were found dead near their holes, 

 having evidently been killed by owls or small carnivorous mammals. 



Alpine Mole-Rat {Tachyoryctes rex). Mole-rat mounds were comnaon about 

 the West Kenia Forest Station, but none were seen between 7,500 and 

 8,500 feet, and from this altitude they ranged to 11,000 feet. They 

 inhabited all of the open grassy plots in the bamboo belt and in the open 

 timber. The "boys" snared many in nooses ingeniously placed in the 

 runs that were opened and closed after the trap was set. VVhile digging 

 into the burrows, several times I found bulky nests of dried grass in side 



