A survey of Nahan's Francolin Francolimus nahani in two tropical forests in Uganda

3 Pages·1997·2.5 MB·

by  Christine Dranzoa

e
A
survey of Nahan’s Francolin Francolinus nahani in
two tropical rainforests of Uganda
C. Dmnzoaa E. Sande I. Owiunjf, andA. Plumptr b
,
Summary:SurveysofNahan’sFrancolinFrancolinusnahaniwerecarriedoutinBudongoandMabira
forestsinSeptemberand October 1996respectively. Playbacksoftherecorded callsformedthemain
surveymethod.Gallsofthisspecieswererecordedforthefirsttime,in19956 whenitwasrediscovered
,
inMabira forestafterhavingbeen ‘missing’ for74years! Positive responseswere obtained inthetwo
localities, at a total of 17 sites distributed in different forest types. Group size ranged between 2-5
individuals. Further detailed research into the conservation status, ecological requirements and
monitoring, andotherbiological data ofthe Nahan’s Francolin is stronglyrecommended.
N
ahan’s Francolin Francolinus nahani is one of Mabira forest reserve covers 320 km2 and is
36 species of endemic African francolins. In located 58 km west of Kampala along the road to
Uganda, it is reported to occur in five different Jinja. Somepartsofthisreservewereharvestedinthe
forests5. Very little is known of its basic biology, early 1900s. Until 1988, intensive coffee/banana
ecology and its conservation status is of global agriculture encroachment claimed large chunks of
concern, although, as yet, insufficient data on its Mabira. Currently,c21%and26%ofthereservehave
conservationstatusisavailabletoassignittoathreat been designated as strict Nature Reserve and Buffer
category, so it is described as ‘data deficient’. Zone respectively.
A recent report on the nesting6 and calls ( I Surveys were conducted by playback of re-
Owiunji, pers obs) of this little known bird from corded calls of Nahan’s Francolin, using tapes
Budongo Forest Reserve formed the basis to this
survey. Allpreviousinformationobtainedfromsight
records was compiled during the colonial era in the
early1900s14.Itwasthereforeimportantthatasurvey
beundertakentodeterminethecurrentstatusofthis
species in Uganda, and its occurrence in different
forest blocks and types. This preliminary survey
aimedtodeterminetheresponseofthespeciestocall
playback, which might prove an adequate census
method for longer term monitoring and ecological
studies.
Study area and methods
BudongoandMabiraarepartoftheremnantLowland ForestsiteW21, where timberwasbeingpit-sawn during
Tropical Rain Forests in Uganda. Both are managed the survey (Christine Dranzoa)
undertheUgandaForestryPolicywhichservesadual
purpose. Under the forestry policy of sustainable
utilisation, timber logging takes place in both re-
serves.
Budongo is a medium altitude reserve lo-
cated on thewest edge ofthewest arm ofthe rift
valley, covering c430 km2 Budongo has been
.
selectively logged since the 1940s and this con-
tinues to the present. Three main areas were
surveyed in two days: site N3 was selectively
logged in the 1950s—1968, W21 has been logged
since the 1950s and was still being logged at the
time of the survey, and N15 (Nyakafunjo) is Timberobtained fromW21 being loaded (Christine
unlogged Nature Reserve. Dranzoa)
90-BullABC Vol4No2 Nahan’sFrancolinintwoUgandantropicalrainforests:Dranzoaetal
previously made in Budongo by I Owiunji and A count accurately the number of birds. Number of
Plumptre and soliciting responses through coun- individuals was 2-5, mean = 3-5 (n=4) (Table 1).
ter-calling and or calling them out. A similar Plumptre6recordedagroupofsevenbirdsinBudongo
procedure has been used for monitoring rails in in 1995.
Aldabra3 Inbothstudyareas, existingtrailsserved These surveys have revealed that Nahan’s
.
astransectlines. BudongoandMabiraforestswere Francolin population estimates can be made using
surveyedfrom28-29September1996andfrom15- playback,andthattheyarestillpresentinMabiraand
22 October 1996 respectively. Along each trail Budongoforests despite active logging in Budongo,
system, calling stations were established at 200 m especiallyatsiteW21.Wetriedinducingbirdstocross
intervals and calls played for 2-3 mins. Replays open areas in Budongo butwere unsuccessful; four
were made at least five times at each stationwhile birdsatButuku(Mabira)didcrossatrack.Otherbirds
adjusting the volume alternately from high to low appearedshy,uponreachinganopenareatheymoved
andviceversa.Fiveminuteswerespentateachsite awayfromit.
waiting for counter-calling. If a response was
elicited, wetriedtoattractthebirdsbyplayingthe
Table 1 Different sites, number of sample points (SP), positive
tape continuously for at least ten minutes to bring groupresponses(+Ve)and numberofindividualsseen inagroup
them into view. Individuals within each group (IG); NS = notseen
attracted to playback were counted whenever
possible and their location noted. Site SP +Ve IG
BUDONGO
Results and discussion N3 selectively logged 27 5 2
N3 Swamp 3 3 NS
Recorded calls N15 unlogged 18 0 -
Nahan's Francolin responded to playback in both W21 logging continues 7 2 5,3
forestsurveys.Thecallcanlastupto 16-20s,becom- MABIRA
inggraduallylouderapproximatelyhalfwaythrough Gangu Valley 10 1 NS
the call, particularly if there is another bird calling Namusha Hills 7 2 NS
nearby. Fig 1 showsthecall. Butuku Bufferzone 7 4 4
At all sites, where counter-calling was encoun- Grassland 9 1 NS
Nature Reserve 8 0 -
tered,responsesvariedfrominstantaneoustoalagof Radio Hill 5 0 -
c5-7 mins (total forwhich response time was noted
= 15).Birdsusuallyremainedconcealed.Twogroups
in Budongo, one in swamp forest and another in Future studies
mixedforest, answeredlongafterthe tape hadbeen Thissurveyispartofamajorstudyoftheecologyand
stopped. InMabira, a similarsituationwas observed assessmentofthepopulationandconservationstatus
in birds near Butuku. Dense vegetation usually in of Nahan’s Francolin in Uganda. It is hoped, with
secondary forest or gaps and swampy areas appear financialsupport,toproduceamanagementstrategy
to be favoured by the species. Five sites in which forthespeciesinUganda.Datawillbegatheredonthe
positive responses were registeredwere in swampy impactofselectiveloggingofBudongoForestonthe
areas. This survey provided the first records of long-term conservation of Nahan’s Francolin, their
Nahan’s Francolin in Mabira Forest since those by distributioninallremnantforests,foresttypes,breed-
van Someren in 1916 and 19221 ing, feeding behaviour and other ecological
.
requirements.
Group size
Nahan’sFrancoliniselusiveindensevegetation.Only Acknowledgements
23% (n=17) ofgroups were seen sufficientlywell to The survey was funded by the Partridge, Quail and
Francolin Specialist (PQF) IUCN group. Makerere
University Institute of Environment & Natural Re-
•I tti}} ii >j >.tr! 1 i yhJ: i '1!'i M ! Ml' f’ * sFooruersctesP(rMojUeIcEt,NRU)g,aBnidrad,LifperUogvaidneddaafancdiltihtieesBufdorontghoe
fieldwork. We are very grateful toJosephine Wong
who made the sonogram. DrD E PomeroyandMrJ
Fig 1. Sonogramoftheterritorial call ofNahan’sFrancolin Linsell provideduseful advice. 7:
Fmncolinus nahani
Nahan’sFrancolin intwo Ugandantropicalrainforests:Dranzoaetal BullABCVol4No2-91
References 5. Urban, E.K., Fry, C.H. andKeith, S. (eds) 1986. The
1. Carswell, M. 1986. Birds of the Kampala area. BirdsofAfrica.Vol 2. London: AcademicPress.
Nairobi: EastAfrica Natural History Society. 6. Plumptre,A.J.1996.TwonestsofNahan’sFrancolin
2. Collar,N.J., Crosby,M.J. andStattersfield,A.J. 1994. intheBudongoForestReserve, Uganda.Bull.ABC
Birdstowatch2: theworldlistofthreatenedbirds. 3: 37-38.
Cambridge: BirdLifeInternational. ac/oMakerereUniversity,Box7298,Kampala, Uganda.
3. Hambler, C., Newwing, J. and Hambler, K.1993. hInstituteofBiologicalAnthropology, OxfordUniversity,
Population monitoring for the flightless rail 58BanburyRd, Oxford, UK.
Dryolimnascuvierialdabranus.BirdConservation
International3: 307-318.
4. Hamel, P.J. 1980. Avifauna of Kifu and Mabira
Forests,Uganda.Proc.IVPan-AfricanOrnithologi-
calCongress-. 143-165.
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