Do wild herbivores influence diet selection by cattle?
Wilfred O. Odadi1,3, Truman P. Young1,2 and J. B Okeyo-Owuor3
1. Mpala Research Centre, 2. University of California, Davis, 3. Moi University
Introduction
Concern over negative impacts on livestock production often associated with wildlife has been
rising among livestock owners in semi-arid rangelands. This has led to extermination of (larger)
wildlife populations from some private and communal properties. As a result, there has been
growing recognition that the future of wildlife conservation outside protected areas will depend
partly on better assessment of the impacts of wildlife on livestock.
Results
Selection of grasses, which constituted the bulk (86%-99%) of cattle diet, did not differ between
treatments during either season. However, during the dry season, selection of forbs by cattle
was lower in plots shared by cattle and wildlife (WC and MWC) than in those exclusively
accessible to cattle (C) (Figure 1). These differences were related to reductions in cover of forbs
in plots accessible to both cattle and wildlife (Figure 2). These differences were greater in plots
with megaherbivores (MWC) than those without them (WC).
15
25
Wet season
5
Megaherbivores
Objective
10
0
We investigated the impacts of large wild herbivores on cattle diet selection in a semi-arid
rangeland in Laikipia District, Kenya.
Methods
5
WC
MWC
C
Treatments
Figure 1. Percent of bites taken by cattle on forbs across treatments at
different seasons.
WC
MWC
Treatments
Figure 2. Percent cover of forbs across treatments at different
seasons.
Conclusions and Management Implications
The study was conducted at Mpala Research Centre, using a set of 4-ha exclosures established
in 1995 by the Kenya Long-term Exclosure Experiment (KLEE). These consisted of the following
three treatments of herbivore combinations (replicated across three experimental blocks):
3)
15
(elephants and giraffes)
C
1)
2)
Wet season
Dry season
20
Cover (%)
Bites (%)
Dry season
10
Only cattle allowed (“C”)
Moderate-sized wild herbivores > 15 kg (zebras, hartebeests, gazelles, elands,
oryx and buffaloes) and cattle allowed (“WC”)
Megaherbivores (elephants and giraffes), moderate-sized wild herbivores and
cattle allowed (“MWC”)
Wild herbivores appear to play no role in influencing selection of the major cattle diet
components, suggesting their compatibility with cattle in this ecosystem. This compatibility can
be enhanced by assessing nutritional implications associated with reductions in cover and
selection of forbs in areas shared by cattle and wildlife during dry seasons, and putting in place
corrective measures such as supplemental feeding to minimize any negative impacts.
We observed ten 2-3 year old ‘Boran’ heifers obtained from Mpala Ranch, for the number of
bites taken on different plant species in each treatment plot during August 2001 (wet season)
and February 2002 (dry season). Vegetation cover data for plots were obtained from KLEE.
This research was supported by grants from National Science Foundation and African Elephant Program of the U.S.
Fish and Wildlife Service (to T. P. Young). We thank Nick Georgiadis, John and Ken Wreford Smith, and especially
the late George Small for hosting us, and providing experimental site and animals; and Charles Warui and Frederick
Erei for field assistance.
Cattle and moderate-sized wild
herbivores (zebra and buffaloes)