The zoogeography of the montane forest avifauna of eastern Tanzania - Biogeography and Ecology of the Rain Forests of Eastern Africa - page 223

albonotata (l), Black-fronted Bush-shrike (Ul,
Uz) and Kenrick's Starling (Ul).
More research, especially detailed populaion
studies, is very likely to show that seasonal
alitudinal movements are of greater signiicance
than has hitherto been realised. This means that
effecive consevaion of a forest bird community
requires adequate protecion of the enire
alitudinal spectrum of forest upon which the
component bird species depend.

carried out by A. J. Beakbane have
revealed a number of sunbirds of this
superspecies which are dificult to ideniy
to species; it must now be doubted
whether Moreau's Sunbird consitutes a
valid taxon.
2. West African derived species. Seven of the
East Coast Escarpment endemics have
close relaives in the montane and lowland
forests of West and Central Africa. These
seven are best considered isolated forms
of species with more westerly
disribuions, which have since diverged to
the specific level. They are the Usambara
Eagle Owl, White-chested Alethe,
Sharpe's Akalat, Chapin's Apalis, White-
winged Apalis, Mrs Moreau's Warbler
Bathmocercus winree and Banded Green
Sunbird. These all form superspecies with
West African species (see Hall & Moreau
(1970) and Snow (1978) for details).
3. Species of Asian origin. The Red-capped
Forest Warbler Othotomus metpias is a
tailor-bird of a genus otherise consising
of Asian species. The Long-billed Apalis
Apa/is moreaui should probably also be
placed in Othotomus and is likely to be
closely related to the Red-capped Forest
Warbler (Fy, 1976; Stuart, 1981b).
Interesingly, there are also a ew species
of probable Asian origin in the Albertine
Rift forests, most notably the Itombwe
Owl Phodilus pigoginei and the African
Green Broadbill Pseuocaptomena rauei.
The presence of these species in African
montane forests suggests a much wetter
climate in Southwest Asia in the past than
eists today.
4. Species of lowland origin. Three East
Coast Escarpment endemics have probably
originated from lowland species which
occur nearby. The Tiny Greenbul is
merely the disincive montane race
(albigula) of the East African lowland form
(rabat). The Uluguru Bush-shrike is
probably a montane orest derivaive of the
widespread Grey-headed Bush-shrike
Malaconotus blanchoti. And the Usambara

The ori,n of the East Coast Escarpment
monane avfauna

Jensen & Stuart (1985) and Stuart (1986) dis-
cussed the origin of the Cameroun montane for-
est avifauna and found it to be derived from a
wide variety of sources. The same can be said of
the East Coast Escarpment montane forest
avifauna.
The 21 endemic and near endemic forms,
listed in Table 10.5, can be considered to have
had four basic origins. These are as follows.

1. Endemics which evolved in situ. These are
species which seem to have originated in
the East Coast Escarpment itself. Nine
species fall into this categoy, seven of
which are 'ancient' species without close
relaives. These 'ancient' forms comprise
Sheppardia montana, S. lowei and Cossypha
anomala, and the genus Modulatix (a
genus of uncertain afiniies endemic to
the East Coast Escarpment forests).
Swynnerton's Forest-robin Swynnetonia
swynnertoni and the Rufous-winged
Sunbird are also 'ancient' forms which
probably originated in easten Tanzania.
By contrast, Loveridge's Sunbird and
Moreau's Sunbird Neaarinia moreaui are
examples of recently evolved species in the
East Coast Escarpment. Stuart & van der
Willigen (1980) have suggested that
Moreau's Sunbird is a hybrid form
between Loveridge's Sunbird (the
Uluguru endemic) and the widespread
Easten Double-collared Sunbird .
mediocis. More recent studies being