A Field Study of a Population of Leopard Toads (Bufo regularis regularis)

The studies to be described were made from April 1955 to March 1957 while we were living in the Rukwa Valley, south-west Tanganyika. This valley is a part of the rift valley system of East Africa and lies about 80 south of the equator at a height of some 2600 ft above sea level. All the observations were made at one place, Kafukola, a camp belonging to the International Red Locust Control Service, situated near the foot of the 3000 ft western escarpment. At Kafukola is a freshwater spring which has been dammed to form a pool about 15 x 25 sq. ft in area and some 2 ft deep at the centre. The pool has steep banks 1-2 ft high and is overhung by large fig trees whose roots extend into the pool in places. From the dam the water runs into a stream by the side of which is a banana grove. To the south of the pool the ground is largely cleared but on the other sides the grass is usually tall. Most of the observations on movement were made on the south side because of the difficulty of finding the toads in the tall grass elsewhere, and even here were restricted to the cleared area which extends about 100 yd from the pool. A brief description of the vegetation is given by Pielou (1952).