April A August. 1999 
popular charismatic organisms representing our natural 
uorld. and several have become significant "flagships" 
lor arousing public interest and support of wider 
conservation programs (Burnham eial.. 1992. Thiollav 
1992). 
The Ngurumans 
The Nguruman area (l°50’S. 36°05’E) is about ihrcc 
hours by road southwest of Nairobi. Climatically, the 
area is hot and dry (monthly mean maximum 
temperatures ranging from about 32 39°C (Brightwvll 
etal., 1992) with rainfall averaging about 525 mm per 
year t Brightwell eial. 1 997). The Nguruman area and 
the immediate surroundings (Lake Mugadi. Lake Natron 
and the Lotta Hills) arc renowned for their avifauna, 
and in particular, their rich raptor community A 
staggering 42% of the raptors that breed in the cast 
African tropics, occur in the Ngurumans. Almost 40% 
of breeding raptors in Hast Africa have hecu listed as 
either Vulnerable. Threatened or Near-Threatened in 
the preliminary Red Data Lisi of East African birds in 
jeopardy (Bennun and NJorogc. I99f» and therefore 
provide the impetus for conducting immediate raptor 
studies in a potentially threatened area (see threats 
below). Furthermore, three Globally- threatened bird 
species (Grey-crested Helmet Shrike;. Red-throated Tit 
and Jackson’s Widowbird). four Rcgjonally.threaiened 
species (Bearded Vulture. African Crowned Eagle, 
Purple- throated Cuckoo-shrike and Stri|icd Flufftnili 
and one Restricted-range species (Hunter’s Cislicola) 
occur in the Nguruman area (Bennun and NJorogc, in 
pr*l> ) By virtue of its closeness to Nairobi, its rich 
ibui poorly studied) fauna, and dlveisily of habitats, 
die Nguruman area provides ample opportunity for 
biological research aimed at providing effective 
conservation and management guidelines fot its 
preservation. 
The universal problem or rapidlv changing land-use 
patterns, without a coherent plan for conserving 
biological resources, threatens to destroy the future nf 
die Nguruman area. The markei in northern Europe 
lor exotic vegetables is the impetus behind the grow th 
ol cxport-ciop farming in Kenya As a result, there arc 
plans to increase the present 500 acres under 
horticultural development to 5000 acres using irrigation 
(gravity and pump-driven) water taken from the 
Entosopia and Oloibortoto rivers originating above the 
Nguruman escarpment and from the Ewaso Ngiro river 
in the plains below The growth and expansion of export 
vegetables has been at the expense of local subsistence 
crops such as mar/e and hcans (hist year, maize and 
beans had to be imported to sustain local communities) 
(Sithananihain. pers comm ). Indiscriminate use of 
pesticides and fertilisers to maximise crop production 
is on the increase and has been estimated at proportions 
four to eight times the recommended levels of use. This 
could have far-reaching negative effects on the livestock 
of tlic local pastoral communities who comprise the 
majority in the area, not to mention the impacts of 
contamination on biodiversity. The local communities 
also depend on water from the escarpment rivers and 
the Ewaso Ngiro for consumption. Already, there is 
evidence of salinisation of farmland, primarily due to 
fertiliser inputs. Additionally, social disharmony among 
farmers has recently been reported, as a result of 
competition for access to rationed water The growth 
of export farming also strains the group ranch social 
structure by increasing ihc demand for subdivision and 
privatisation of what arc mostly at present, communally 
owned grazing lands. Finally, and perhaps most 
importantly, the expected increase in horticultural 
acreage along (he Ewaso Ngiro River poses a potential 
threat to the health of Lake Natron, the major breeding 
site for flamingos In Africa and a world heritage site. 
What can be done? 
At a recent meeting convened by 1CIPE at their 
headquarters In Kasarani. several institutions concerned 
with issues of conservation, community development, 
and sustainable land management were invited to 
participate in a workshop aimed at providing beneficial 
alternatives to vegetable export farming as well as to 
formulaic suitable guidelines for the conservation ot 
the area The response was overwhelming and the 
general consensus was to implement a multi-disciplinary 
or integrated approach towards better understanding the 
ecology of the area. Without a thorough understanding 
of the ecological factors affecting the dynamics of an 
ecosystem, conservation management cannot be 
properly focused We are all only too familiar with the 
ecological problems that affected Lake Naivnsha Hie 
Nguruman area Is unique and we as conservationists 
must do all we can to promote sustainable use ol 
biological resources. At the ICIPE meeting, the 
following objectives were proposed as part of an overall 
multi-disciplinary strategy to monitor changes affected 
| V •-banging land-uses as well as to gather vital biological 
information which will be used to effectively conserve 
and manage the Nguruman area: 
• use of aquatic invertebrate biodiversity 
measurements (Resh and Jackson 1993. Chuttcr 
1994) to assess water quality of streams immediately 
upstream and downstream of irrigation sites; 
• evaluate die effects of pump irrigation farming on 
water quality of the Ewaso Ngiro River and estimate 
the buffering capacity of the Ewaso Ngiro swamp, 
upstream from Lake Natron; 
• characterise land quality and soil arthropod diversity 
on cash crop farms by comparing appropriate 
cdaphic indicator variables in horticultural farms, 
mixed horticulture/orchard farming and adjacent 
non-farm sites; 
• evaluate orchard farming (e g mangoes) as an 
economically viable alternative to high turnover 
insecticide and fertiliser intensive farming; 
• evaluate the role of bees in providing pollination 
services and their cascading effects on the ecology 
of the area. 
