A survey of the highland grassland endemics in Mau Narok/Molo Important Bird Area, Kenya

4 Pages·2003·2.4 MB·

by  Kariuki 'ndang''ang''a

A survey of the highland grassland endemics in
Mau Narok/Molo Important Bird Area, Kenya
KariukiNdanganga, RonaldMulwa andPatrick Gichuki
L’etendue, larepartition etlaqualitedecequi reste de 1’habitat herbeuxdans les Mau Narok-Molograsslands.
Zoned’ImportancepourlaConservationdesOiseaux(ZICO)auKenya,onteteevalueesdu 16au24septembre
2001. Les auteurs ont egalement estime la repartition et la densite de deux especesglobalement menac&set a
repartition restreinte, laSentinelledeSharpeMacronyxsbarpeietlaCisticoledesAberdare Cisticolaaberdare. 1a
plusgrandepartie(48%)delaZICOetaitconstitutedecultures,tandisqueleszonesherbeusesnecomprenaient
que 33%, les plus importantes se trouvant dans la partie la plus meridionale, occupee principalement parla
communautepastoraleMasai.LaSentinelledeSharpeavaitunedensitede 1,2individusparhaetetaitladeuxi&me
especelaplus communementobservee. La Cisticole desAberdareaeteobservtedanstroisparcellesseulement,
avec un total de sept individus. La conversion a grande echelle en cultures d'orge et de froment constitue une
menacegravepourleszonesherbeuses.LaZICOenpossedetoutefoisencoredesetenduesconsiderablesdehaute
qualiteetelleestainsi importante pourlaconservation desespecesendemiquesdecet habitat. Lesinitiativesde
conservation devraient done se concentrersurces zones.
T
he Mau Narok/Molo Grasslands Important Bird MacronyxsharpeiandAberdareCisticolaCisticolaaberdare,
Area(IBA) holdssignificantareasofKenya’sunique both classified as Endangered by BirdLife InternationaF.
highland grasslands. This and Kinangop Grasslands IBA No adequate information concerning the status ofeither
(Fig 1), eitherside ofthe central RiftValley, are the only species or their grassland habitat is available from Mau
sitesthatholdsignificantareasofthishabitat,which lacks Narok/Molo Grasslands. Between 16 and 24 September
any formal protection in Kenya and is rapidlyvanishing. 2001, wesurveyed the extent, distribution and condition
Theyarehometoseveralmigratorybirdspeciesandvarious of the remaining grassland habitat, and estimated the
specialised grassland birds, and are ofkey importance as distributionanddensityofthesespecies. Wealsousedthe
they harbour the restricted-range Sharpe’s Longclaw surveyto(1)increaseawarenessamongthelocalcommunity
oftheconservationvalueoftheIBA,(2)makeopportunistic
contactswithinterestedmembersofthiscommunitywith
the aim of initiating a local conservation group or Site
Support Group (SSG), and (3) involve and train three
members of the Kinangop Grasslands SSG in grassland
surveymethods. Here, we present the basic results ofour
work.
Mau Narok/Molo Grasslands
The Mau Narok/Molo Grasslands IBA is an extensive
montane grassland situated on the crest of the Mau
escarpment, which forms the western wall ofthe central
RiftValleyinKenya.Thishigh,openplateauoccupiesc80
kmsouth-easttonorth-west,andisbounded(andpartially
interrupted)bytheMauForestcomplex.Rainfalliscl,000
mm
peryear,andtheoriginalvegetationisshortgrassland,
with some heather and scrub on ridges where soils are
deeper.Theareahashighpotentialforagriculture,andhas
gradually been settled since the 1950s; it is now heavily
populated,withalandscapeseverelymodifiedbycultivation.
Cereals are themain crops.
TheIBAissitedinNakuruand(asmallpartof)Narok
Figure 1.TotalrangeofSharpe’sLongclawMacronyxsharpei districts, within RiftValley province. Population density
(shadedarea)showingthelocationsofthestudyarea(MauNarok/ in Nakuru district is high (164 per km2)8. The main
MoloGrasslandsIBA) andKinangopGrasslands (theprobable occupantsofthestudyareaaresmallholdersoftheKikuyu
strongholdofthespecies).
64-BullABC Vo! 10No 1 AsurveyofthehighlandgrasslandendemicsinMauNarok/MoloIBA:Ndangangaetal
andKalenjincommunities(MoloandnorthernMauNarok) ened species, was the fifth most abundant species. The
andtheMasaicommunity(whoaretraditionallylivestock longclawwasencounteredin 17outof37surveyplots,and
herders) inthesouthernMauNarok. was thesecond most frequentlyencounteredspecies after
Grassland Pipit,whichwas recordedin 22 plots.
Methods Aberdare Cisticola was recorded in only three plots,
Wecontinuouslymappedbroadland-usecategoriesovera withatotalofsevenindividuals,suggestingalowdensity.
predeterminedroutethroughthegrasslandsbyestimating However,itisprobablethatthespecieswasunder-recorded
the percentage cover of each habitat around points en duringthecountsasthetransectmethodusedwasdesigned
route, at intervals of 1.5 km. Transects were conducted for surveying Sharpe’s Longclaw and may not be as
every3kmtosurveygrasslandbirdsinselected 1-haplots appropriateforthecisticola,whichmayalsoutilisedifferent
withinlargergrasslands.Thirty-sevenplotsweresurveyed. habitat. The few individuals to be locatedwere all on or
Theareaofeachlargerpatchwasrecordedas <5, 5-20or close to slightly bushy grassland. Other commonly
>20ha,andtheplotsweresurveyedbyateamofsixpeople encounteredspecies(andthenumberofplotsinwhichthey
spreadacrossthewidthofthearea,walkingslowlyacrossit were recorded) were Common Fiscal Laniuscollaris (17),
10-20 m apart. All species and individuals flushed were Red-capped Lark (14), Stonechat Saxicola torquata (ten),
recorded. Measures ofgrassland quality were also noted Baglafecht Weaver Ploceus baglafecht (nine) and Wing-
within the plot using a system developed for monitoring snappingCisticola Cisticolaayresii (eight).
grasslandhabitatinKinangop. Grassheightwas recorded Asgrasslandswereestimatedtocoverone-third(cl3,000
asG1(short),G2(mediumlength)andG3(tall).Percentage ha) ofthe IBA, the areasurveyedwas c0.3% ofthe IBA’s
tussockcoverwasrecordedasT1 (noorjustafewscattered grassland area. The plots were, however, within patches
tussocks), T2 (moderate tussock covering up to 30% of totallingapproximately2,150 ha (16.5%).
area),T3 (considerabletussockcovering30-60%ofarea),
andT4(densetussockcovering>60%ofarea).Thenumber Grassland cover
oflivestockandotherbirdspecieswithin theentirepatch Grasslands covered only one-third ofthe estimated area
were also recorded. (c40,000ha)1oftheentireIBA(Table1),whilecultivation
covered approximately 50%. The spatial distribution of
Results grasslandsvariedbetweentheMoloandMauNarokareas
Sixtyspecieswererecordedinthegrasslandpatchessurveyed. of the IBA. Most (75%) of the 20 grassland patches
Sharpe’s Longclaw occurred at a relatively high overall surveyedinNarokdistrict(southernMauNarok)were>20
density,of1.2individualsperha,throughoutthe37plots, ha. Only35%ofthe 17patchesinNakurudistrict (Molo
i.e. slightlyhigherthan the0.85 perhafromsampleplots block and northern Mau Narok) were >20 ha in size.
inKinangoprecordedbyMuchaietaP.However,theMau GrasslandsinMolooccurredaspatchesofvaryingsizesand
Narok/Molodensitycompareswellwiththatnotedonlyin were mostly isolated by cultivation. The main crops in
thoseplotswithshortgrassandtussocksatKinangop5.The Moloweremaizeandpyrethrum.Wheat,barleyandpotatoes
speciesoccurredat2.2perhainplotswithingrasslandsof were also common.
>20 ha, compared to those of<20 ha where the species GrasslandextentanddistributioninMauNarokvaried
occurredatdensitiesof0.2perha.Basedonoveralldensity, between that occupied by smallholders and that by the
itwasthefourthmostabundantspeciesafterBlack-winged mainly pastoral Masai community. The north-west Mau
Lapwing Vanellus melanopterus Red-capped Lark Narok was heavily cultivated and only 14.4% held
,
CalandrellacinereaandGrasslandPipitAnthuscinnamomeus. grasslands. Smallholders of the Kalenjin and Kikuyu
Jackson’s Widowbird Euplectesjacksoni a Near-Threat- communities, who mainly cultivate maize, potatoes and
,
Table 1. Percentage land-usewithin Molo (n=30) and Mau Narok(n=55)areasofthe Mau Narok-MoloGrasslands ImportantBirdArea
(IBA), Kenya. Estimatesfortheentire IBA(N=85)arealsopresented.
Landuse Molo MauNarok EntireIBA
Mean SD Mean SD Mean SD
Grassland 33.3 23.6 33.2 19.7 33.3 21.0
Cultivation 45.1 22.6 49.2 18.9 47.8 20.3
Exotictreeplantations 14.0 8.4 6.2 5.6 9.0 7.6
Settlements 5.7 3.5 3.0 2.1 3.9 3.0
Indigenousforest 2.2 6.7 6.2 11.6 4.8 10.3
Dams/waterreservoirs 0.1 0.5 0.0 0.0 0.0 0.3
Woodland/thicket 0.0 0.0 2.0 9.0 1.3 7.3
AsurveyofthehighlandgrasslandendemicsinMauNarok/MoloIBA:Ndangangaetal BullABC Vol 10No 1-65
vegetables, occupied most ofthis area. Elsewhere in Mau nant grasslands at Mau Narok/Molo IBA were larger,
Narok, where the Masai are the principal land-users, although isolated by large areas under cereals, probably
grasslands covered 43.2%. In particular, more extensive because most land holdings are larger in Mau Narokand
grasslandswerefoundin two regionsofMauNarok: west Molo than in Kinangop6.
ofMauNaroktown aroundOlokurto, andsouthofMau Throughout the study area continuous grasslands
Narok between Olorropil and south through 01 Chorro appear to survive mostly along shallow sloping valleys.
and 01Joro. Seventeen (46%) of the surveyed grasslands were along
Principal crops in cultivatedareasofMasai landwere watercourses and none was <5 ha. Most grasslands were
barley and wheat, which mainly occurred on extensive heavilygrazedandhadshortgrass,astheMasaikeeplarge
farms accessible to agricultural machinery (Fig 2). The herds ofcattle on these areas. We counted 2,351 cows,
Masai communitytraditionallypractised pastoralism and 7,307 sheep and goats, and 42 donkeys within an areaof
tended to abandon extensive pasture to their livestock c2,000ha,atagrazingintensityofninelargeanimal units
(Fig3). This practice is, however, becoming rarer due to (LAU) perha. Weassumethatasingle LAU isequivalent
theadventoflarge-scalecropcultivation.Barleyandwheat, to one cow or five sheep, and represents the metabolic
whicharepotentiallymorelucrativethanlivestockfarming, equivalentofa454-kgcow7
arecurrentlybeingincreasinglycultivatedandposeamajor A higher proportion (15) ofthe plots had moderate
threat, especially to large grasslands in southern Mau tussockcover. Onlytwo plots haddensetussock, whereas
Narok.Theremaininggrasslandsarenowheavilygrazedas nine plots completely lacked or had just a few scattered
the pastoralistsstill herdlarge numbers ofcattle. tussocks. Sharpes Longclaw strongly prefers short grass
IncomparisontoKinangopGrasslands IBA, therem- with tussocks34. Mostofthesurveyplots (62%) hadshort
grasswith tussocks.
Most (20) of the surveyed grasslands were >20 ha,
whereas 13were5-20ha.Onlyfourpatcheswere<5hain
size.The82pointswhereland-usewassurveyedcovereda
total areaof14,496 ha (c36% ofthe IBA).
Training SSG members, awareness and
contacts
The three SSG members from Kinangop gained skills in
grassland bird survey techniques. Posters have been
developed by the Friends of Kinangop Plateau to raise
awareness concerning the importance of conserving
Kinangop Grassland IBA, which faces similar threats to
MauNarok/Molo.Thirteenofthelatterposters,22national
posterswithinformationconcerningall Kenyan IBAsand
Figure2. Largebarleyandwheatplantationsarereplacing
grasslands,withsmallgrasslandstripsbeingleftalongwatercourses 25 Kenyan IBAfactsheetsweredistributed. Talksoutlin-
(Kariuki Ndang’ang’a)
Figure3. RemnantareasofthepreferredhabitatofSharpe’s Figure4.Asurveymemberpresentsanawarenesstalktopupilsat
LongclawMacronyxsharpei(shortgrasswithtussocks) inthe alocalprimaryschoolinMolo (KariukiNdang’ang’a)
Masai-occupiedareaofOlokurtoarea,MauNarok(Kariuki
Ndang’ang’a)
66-BullABC Vol 10No 1 AsurveyofthehighlandgrasslandendemicsinMauNarok/MoloIBA:Ndangangaetal
ingtheconservationimportanceoftheIBAweremadeto References
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Acknowledgements
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[email protected].
Supported by ABC ConservationFund
AsurveyofthehighlandgrasslandendemicsinMauNarok/MoloIBA:Ndang’ang’aetal BullABCVol 10No 1-67