BIOGEOGRAPHIA — vol. XIV - 1988 {Pubblicato il 31 dicembre 1990) The Biogeography of Somalia The bird community of riverine forest in Somalia BRIAN WOOD Ecology and Comervm.‘z'0Iz U/zit, Depmtmem‘ of Biology, Um'71e7'rz'ty College London, Gower Street, London W/CIE 6BT, UK. SUMMARY The area of riverine forest in the Jubba valley has been reduced by over 90% since 1960. Only two sizeable blocks now remain and these were studied by the Somalia Research Project in 1986. As part of these studies, over 500 birds were mist-netted in the forest understorey. A group of 47 bird species is considered to be dependent on riverine forest and all of these have very restricted ranges in Somalia. As yet, the substantial reduction in area of riverine forest does not seem to have caused a comparable reduction in bird species. The remoteness of the Jubba valley from Quaternary forest refugia appears to have exerted a more important control on its number of bird species. Competitive interactions between the species which make up this community are considered, as thay may also restrict the number of species that occur. There are several examples of guilds of species which seem to coexist through size separation. If the remaining forest was protected, most of the typical bird species would probably survive. How- ever, the threats from further clearance and from insecticidal sprays are considerable. There are also economic benefits to be gained by protecting riverine forest, since it is a source of medicinal plants, construction materials and honey from wild bees. Forest helps to reduce erosion and flooding of agricul- tural land. It is to be hoped that the Somali government will take this opportunity to demonstrate a committment to nature conservation by introducing effective protection measures as soon possible. INTRODUCTION Little riverine forest now remains in Somalia. At one time it clothed the banks of both the major rivers for most of their length (Pichi—Sermolli 1957), but only tiny fragments now exist along the Shabeelle. For the Jubba valley it has been possible to quantify the recent rate of loss of riverine forest by comparing aerial photographs taken on three different dates (Deshmukh 1987). From 1960 to 1987 a reduction from 9350 ha to 900 ha was recorded. Most of what remains is fragmented and there are now sizeable areas of riverine forest only in the Middle Jubba between Fanoole and Bu’aale. Even in this stretch, over 850 ha was cleared between 1983/84 and 1987, a loss of 63% in less than 4 years. Clearly, unless protection measures are rapidly introduced and enforced, there will be no forest remaining by the end of this century. A gradual and continuous erosion of the area of riverine forest has prob- ably taken place for as long as there have been settlements in the valley, but recent developments have given added impetus to its removal. A major dam is to be constructed north of Bardheere in order to generate electricity and 467