Ecology of the Zanzibar red colobus monkey, Colobus badius kirkii (Gray, 1 968), in comparison with other red colobines - Biogeography and Ecology of the Rain Forests of Eastern Africa - page 252

Table 12.5. Food sp ecies diversiy in th ree studies of red colobus (n umber of ood species used shown in
parentheses)

Zanzibar (this study) Tana Kibale

(Marsh, 198la) (Sruhsaker, 1975)

Group I Group II Group III Group M Group CW

I.95 b

Apr. 1.664 1.811 I.753d

e

2.98 b May 2.002(15) 2.072(15) 1.949

2.22 b

June 1.719(17) 1.508(11) 1.874

2.65 b

July 2.106(16) 1.705(9) 1.745

2.65 b Aug. 2.341(25) 2.205(17) 1.112(5)

1.415(9)
1.698(12)
1.427(8)
1.675(15)
1.396(10)
1.765(16)
1.990(22)

1.501

2.55 b
2.73a

Sept. 2.274(26) 1.955(12) 1.981

2.71 b

Oct. 2.021(16) 1.795(14) 2.012c

2.131d 2.46a

2.84 b Nov. 2.506(20) 2.033(17) 2.132c

2.208d 3.03a

2.75 b Dec. 1.700(27) 2.220(30) 1.923&

2.40a

1.992d

Jan ! 2.83 b

2.41a

2.497(37) 2.053(27) 1.838d

Feb. 2.318(29) 2.106(18) 2.104 2.l5b

2.77a

2.6z b
2.62a

Mar. 2.326(30) 2.192(19) 2.026

Average 2.12 1.97 1.56 1.93 2.60

Note: a1970; b 1971; c1973; d1974; '1980/1981.

where P; represents the proporion of observa-
ions for each food species or item.
Table 12.5 shows food species diversity indices
for Zanzibar, Kibale and Tana red colobus
monkeys. Table 12.6 shows ood item diversiy
indices or . b. kirkii and Kibale red colobus
monkeys. Both tables show that Kibale red col-
obus consistently had the highest indices followed
by groups I and II of the Zanzibar red colobus,
then Tana red colobus and finally group III of the
Zanzibar red colobus.

to the diet of the top ten species and their
abundance measured in percentage of Basal Area
(group I: r5 = 0.770, P < 0.01; group II:
r5

0.745, P < 0.05; group III: r5 = 0.758,
P < 0.01). Feeding on these ten most important
food species, which contributed 85.4, 88 and
94% of the three groups' annual diet respecively,
was significantly related to their abundance. The
important plants in the area also were the import-
ant food species for the monkeys.
To examine food preferences further, a selec-
ion raio or each species was calculated from the
formula selecion raio SR:
SR= % offeeding records accounted for by species A

=

Fod preerence

n important influence on the extent of feeding
on different species and items may have been
their abundance within the groups' range. There
was signiicant correlaion between contribuion

% oftotalbasal area accounted for by species A
Basal area is closely related to canopy size (Ben-
nett, 1983; Mui, 1991). Because it is measured