The Bird Population of a Settled Valley in the West Usambaras, Tanganyika Territory

Abstract

We are aware that the most satisfactory season at which to determine the number of birds" carried" by any given area is when breeding is at its height, and the birds are in consequence more definitely localised than at any other time. We were not3 free agents in our choice of the date to visit Kongei, but it is doubtful if in any case we could have chosen a much better period of the year. Field work of any description is next to impossible in the" rains." Of East Africa as a whole, it has been stated that breeding seasons generally are dependent on the" rains," but they are much less defined than in the Temperate Zones. In the Usambaras the greater part of the annual rainfall is recorded in two periods, between the end of March and the beginning of June, and between the end of October and the end of November. At Kongei in September an appreciable proportion of the birds were engaged in some phase of breeding activity. The loud song and pugnacity connected in the Temperate Zone with territory holding were little in evidence however, and we have yet to gain a clear idea of what part this element of bird-behaviour plays among tropical birds.