 Reference Base  Status of the black rhinoceros in the Masai Mara National... |
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Morgan-Davies, M., 1996. Status of the black rhinoceros in the Masai Mara National Reserve, Kenya. Pachyderm 21: 38-45, figs. 1-5, table 1
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| Location: |
Africa - Eastern Africa - Kenya |
| Subject: |
Distribution - Records |
| Species: |
Black Rhino |
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The Reserve presently has five distinct rhino distribution areas (Table 1) comprised of closely overlapping individual home ranges of more than one rhino except for Musiara (E), with only one remaining animal. Currently 22 (55%) of the Reserve's 40 rhinos are resident in area A, which has always had a relatively large number of these animals. Mukinya (1973) also records this as being a heavily populated area with 31 (29%) of the 108 rhinos then resident in the Reserve. However, area A is the largest. In terms of density, area D supports the highest number of rhinos per km?, as seen in Table 1.
Table 1 Individual distribution areas, numbers of rhinos and their relative densities in June 1995.
Area Number % of total Distribution Number of
of rhinos population area in km? rhino per km?
A 22 55.0 181 0.12
B 7 17.5 118 0.06
C 4 10.0 58 0.07
D 6 15.0 16 0.38
E 1 2.5 86 0.01
Total 40 100.0 459 0.09
Excluding area of overlap
40 100.0 399 0.10
Overlap of distribution areas
Although four of the five distribution areas presently overlap (Figure 2B), Mukinya (1973) recorded that overlaps only occurred with home ranges and not with distribution areas, and that the latter were clearly separated from each other (Figure 2A). At present there are three distinct distribution area overlaps totalling 60 km? or 16% of the total area occupied by rhinos east of the Mara River (12 km? in areas A-B, 38 km? in areas A-C, and 10 km? in areas B-D). It is possible that these overlaps allow the exchange of genes between members of adjacent distribution areas. Rhinos from geographically separate distribution areas were seen consorting in these overlaps on at least ten occasions between 1992 to 1995 but no mating was observed. In each instance, the rhinos involved had returned to their respective home ranges within two to four days.
Density
Mukinya ( 1973) records that the total area of the Reserve occupied by rhinos in 1972 was 749 km?, thereby giving a density of 0.14 rhino per km?. At present the total area occupied by rhinos is only 399 km?, with a density of 0.10 rhino per km? However, taking into account the 60 km? overlap of distribution (figure 2B), the total area occupied by rhinos is 459 km? with a corresponding density of 0.09 rhino per km?.
Movement of rhinos into and out of the Reserve
Not only is the Reserve an integral part of the Mara/ Serengeti ecosystem on account of the annual migration of about two million ungulates, but also due to the movement, throughout the year, of at least 15 rhinos (the majority being females with their calves) between the Mara and northern Serengeti. These movements are not without their dangers. Although the rhinos move from one protected area to another, they run the considerable risk of being poached by cattle raiders which infiltrate the Park and Reserve along the Serengeti/ Mara international boundary to steal Maasai livestock on the Reserve's western and eastern boundaries.
There could also be the occasional movement of one or more rhinos between the Reserve and the Laleta Hills, four to five kilometres east of the Reserve. Two or three times each year, reports are received of rhinos being seen within the Maasai group ranches, up to eight kilometres north of the Reserve. These could be sub-adult animals from the Reserve trying to establish home ranges, or adults in search of mates.
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