Geology Reference
In-Depth Information
without endemics of their own). In practice,
however, these 26 taxa are distributed in such a
way that the disinction of larger areas of endem-
ism is problemaic. This may result partly from
undercollecing or local exinction, but may
equally well reflect the real situation, i.e. that
within EAT there are no clear subdivisions with a
montane grassland fauna of their own, with the
excepion of Ethiopia. In the following discussion
the areas are grouped on the basis of their prox-
imity and/or geological history.
as a whole. There are three taxa linking north
Tanzania to Kenya .ntanatia abyssinica jacksoni,
Euchysops nandensis, Euchysops c. crawshayz) .
None of these occur in more than four subareas,
but all three are found in the Kikuyu Highlands in
central Kenya.
Easten Arc mountains
Seven taxa occur only here, but there are no taxa
linking all areas together. Neocoenyra heckmanni
indicates a coherence of the areas from Ukaguru
to the Southen Highlands. Similarly,
.
jordani
links three more northern areas. If the two species
proved to be sister species this would be the only
argument for uniing most of the areas of the
Eastern Arc Mountains, but so far there are no
reasons for considering this mountain range (or
the greater part of it) a single area of endemism.
Ethiopia
All eight taxa are endemic. With the excepion of
Eicochysops sebagadis they are subspecies of more
widely spread species. In two cases the related
subspecies occur outside Africa; they will be dealt
with below (Extenal geographic connecions, p.
143). Of the five remaining taxa the related
subspecies occur in Kenya .ntanatia abyssinica,
Euchysops mauensis), northern Tanzania (Pieris
brassicoies, Antanatia abyssinica),
east Zaire/west
Uganda .ntanatia abyssinica, Euchysops mauen-
sis, Lycaena phlaeas), and westen Tanzania
(Euchysops mauensis), while Colias eleao is too
widespread (even reaching South Africa) to be
informaive. What strikes here is the absence of a
relaionship with the Easten Arc mountains.
Malawi
From the geographic point of view there is no
reason to suppose that the three areas would show
a special coherence. Indeed they do not, nor is
there any special relaionship with the Eastern
Arc mountains or even with the Southern High-
lands alone.
West Ta nzania
As with the areas in Malawi the mountain ranges
in west Tanzania cannot be defined as a single
area. There are exclusive connecions with the
next range (Capys c. cathaus, Ha pendyreus major) ,
although not including all areas, and a similar
connecion is extended to west Kenya (Euchysops
m. mauensis).
Kenya
There is one endemic of Mount Kenya plus the
Aberdares (Lepiochysops elgo nae moyo) and one of
the Nandi-Cherangani area plus Mount Elgon
(L. e. elgonae). The two subspecies together unite
the cenral and west Kenyan mountains, i.e. the
mountains east and west of the Rift Valley. There
is one other such taxon, namely Issoria h. han-
nintoni. No further areas of endemism can be
distinguished. See also the next area.
Wes ten Border Range
We use this name for the mountain ranges
bordering the study area as we have chosen it, to
the west, i.e. from Lake Tanganyika to Lake
Mobuto. Although relaively rich in endemics (l0
taxa), there are no endemics found in all four
areas and four taxa are known from a single area
only. Three species (Ha pendyreus aequatorialis, H.
marungensis, Euchysops crawshayz) link (part of) the
Westen Border Range to (part of) Kenya-north-
ern Tanzania, but there are no taxa restricted to
these areas and occurring in all parts.
No th Ta nzania
There are four taxa resricted to the area Kili-
manjaro-Mount Mero-District of Great Craters.
None occur in all three areas, but in one taxon
(Harpendyreus aequatoialis vucanica)
it is the inter-
vening area (Mount Meru) that is missing. Under-
collecing seems a probable cause so that we may
consider this taxon an endemic of north Tanzania
Search WWH ::
Custom Search