A preliminary survey of the montane avifauna of Mt Nilo, East Usambaras, Tanzania

18 Pages·1998·8.8 MB·English

by  Norbert J Cordeiro

Scopus20: 1-18,May 1998
A preliminary survey of the montape
,"
Mt Nilo, East Usambaras, Tdnzantr
NorbertJ. Cordeiro
Nilo Forest Reserve (FR), which encircles the peak ofMt Nilo in the East Usambara Mountains,
Tanzania,comprisesanareaof5872ha. Thisreserve, reachingc. 1500m, isthe highestinthe East
Usambaras and has been comparatively neglected omithologically. This site was visited in August
1994andagain,albeitforonlyafewhours,inOctober 1996.Theprimeobjectivewastolocateglo-
bally threatenedbirds and otherrestricted-range species. The TanzanianMountainWeaverPloceus
nicolliwasrelocatedintheEastUsambaras,thefirstrecordinover60years.Othergloballythreatened
ornear-threatenedspeciesfoundatthislocality includetheSouthernBandedSnakeEagleCircaetus
fasciolatus, Fischer's Turaco Tauracofischeri, Usambara Eagle Owl Bubo vosseleri. Long-billed
Apalis Apalis moreaui. Banded Green Sunbird Anthreptes rubritorques and Amani Sunbird A.
pallidigaster.Inaddition,theAfricanHillBabblerPseudalcippeabyssinicawasrecordedintheEast
Usambarasforthefirsttime.NiloFRisnowknowntobeanimportantsite,bothintheUsambarasand
globally,fortheconservationofbirds.TheEastUsambaraCatchmentForestProjecthasmadegreat
efforts to protect forests in the East Usambaras, including Nilo FR, through a variety ofmeasures.
However,thepressureforarablelandappearstobeagrowingprobleminthearea;duetothehabitat
degradation occurring in the adjacent public land forest, future attention for land and other socio-
economicneedsmayfocusonthebetterprotectedforestreserve.
Background on the Usambaras
The Usambara Mountains, situated in northeastern Tanzania, are part ofthe Eastern
ArcchainofmountainsthatrunfromsoutheasternKenyatosouthernTanzania.These
mountains contain forests that are characterizedby high species endemicity formost
biota (e.g. Rodgers & Homewood 1982, Lovett & Wasser 1993).
During the period ofEuropean exploration in East Africa, various German scien-
tists working inTanzania acknowledgedthe biological importance ofthe Usambaras
(e.g. Engler 1894, Rodgers & Homewood 1982). These and other researchers docu-
mented ahigh species diversity andendemismforinvertebrates, amphibians, reptiles
andplants (see relevant chapters in Lovett & Wasser 1993). In addition, there is one
known endemic bird species (Stuart etal. 1993).
Despite considerable work on the avifauna ofthe Usambaras, only some parts of
the East Usambaras have been well studied, principally in the vicinity of Amani
(Friedmann 1928,Sclater&Moreau 1932-33,Moreau 1935,Ripley&Heinrich 1966,
Stuart & Hutton 1978, Turner 1978, Stuart & van der WiUigen 1979, Stuart 1983,
1989, Newmark 1991, 1993) and, more recently, Mt Mtai (Evans & Anderson 1992,
1993) and some East Usambaralowland sites (Evans etal. 1994, Hipkiss etal. 1994,
CambridgeTanzaniaRainforestProject 1994).Theselaststudiesaddedthreeglobally
threatened forest birds to the East Usambara avifauna and clearly indicated both the
remarkable conservation importance ofthis range and the need for further investiga-
tions.
m
Since the avifauna up to c. 1100 in the East Usambaras was reasonably well
known,itwasconsideredimportanttosurveytheforestabovethisaltitudeinNiloFR,
-1-
2 NorbertJ. Cordeiro
whichisthehighestpointintheEastUsambarasat 1506m(Figs. 1 &2).Thisreserve
v/aspreviouslyrecognizedasthreeseparatereserves,Lutindi,KilangaandNkombola
FRs (Johansson & Sandy 1996, Hamilton & Bensted-Smith 1989), andthis study fo-
cused on the Lutindi area. A. Loveridge had previously collected birds at Lutindi in
December 1926 (Friedmann 1928), and he was followed by collectors employed by
R.E.Moreau,allofwhommadebriefvisitstoKizaraandHundu(Lutindi/Nilo)inJuly
andOctober 1931, respectively (Sclater& Moreau 1932-33).
Themainobjective ofthis study was toassessthebiological andconservation im-
portanceofthissite,anddocumentthestatusofgloballythreatenedbirds.Afollow-up
survey was made in 1995 (Seddon et al. 1995, 1996), the results of which will be
publishedseparately.
Description ofstudy area
m
The East Usambaras rise up from the coast to 1506 with an extensive submontane
plateau between 800-1000 m and are separated from the higherWest Usambaras by
theLwengeraValley. MuchoftheplateauisforestedandtotalforestcoverintheEast
Usambarascomprisesabout45 000ha,afigurethatincludespoorlystockedforestand
woodland (Johansson & Sandy 1996). This once extensive forestnow exists as frag-
mented blocks due to human activities over the last 2000 years (Schmidt 1989,
Newmark 1993). This has been especially so since the late 1800s due to the clearing
forcolonial estates and subsequently fortea and sisal estates, some commercial log-
gingand,morerecently, shiftingcultivation (e.g. Rodgers& Homewood 1982,Ham-
ilton&Bensted-Smith 1989,Tye 1993,M.LL.Katigula&S.Johanssoninlitt. 1997).
The climate, soiltypes andsub-montane/montaneforestofNiloFRhavebeende-
scribed in detail elsewhere (Moreau 1935, Hamilton 1989a, b, Hamilton et al. 1989,
AFIMP 1987,Johansson & Sandy 1996).
Methods
NiloFRwasvisitedfrom2-12August 1994andagainon 10October 1996.Effortwas
concentrated in the areapreviously known as Lutindi FR (see Hamilton & Bensted-
Smith 1989, AFIMP 1987). Methods were designed to locate as many species as
possible inthetime available, especially targeting those species ofconservationcon-
cern. Audio-visual observation and mist-netting were conducted daily: audio-visual
observation servedthepurposeoflocatingasmany species aspossiblein avariety of
habitats and elevations whereas mist-netting enabled the capture ofthe more elusive
understoreybirds.JacobKiure(oneoftheteammembers)andIrotatedbetweendirect
observationandnettingevery3-4handoccasionallyclosedthenetstoallowforbird-
watchingwalks.
Fourmist-netsiteswereestablishedinNiloFRorintheadjacentPublicLandforest
m
(Fig. 2). Site 1, with 19 nets, was in dense forest at 1350 near a river; the canopy
varied from25^0m andtheunderstorey was dense, withDracaena sp. predominat-
ing. EightnetsweresetatSite2,whichwasindenseridge-topforestneartheMtNilo
Montane avifaunaofMtNilo 3
Mtai FR
Lutindi FR
KilangaFR
AMANI 5km
Figure 1. Locationofnorthernforestreserves inthe EastUsambaras, not includingthose
nearAmani(afterHamilton& Bensted-Smith 1989). The threeforestreservesthatnow
formNiloFRare shownbutthe actualboundariesofthisreserve arenotshown
Figure 2.Locationofmistnetsites inNiloFR. Stippledindicatesforestcover; dashed
line,vehicleroad; dottedline,forestreserveboundary
.
4 NorbertJ. Cordeiro
summit at 1400 m; canopy height ranged from 20-30m. The third site, with 10nets,
was atthe summit (1500m); the understorey was thinbutthecanopy (15-25 m) was
closed in most places. Site 4 (1250 m) consisted of 8 nets in very disturbed Public
Landforestwheremuchoftheundergrowthwas affectedbythegrazingoflivestock;
trees varied from 15^0 m, some even taller. Lianas, epiphytes, mosses and lichens
wereespecially common above 1300mingoodforest.
Thenets were operated fromdawntodusk andbirds removedathalf-hourorhour
intervalsdependingonthecapturerates.AllbirdswereringedwithEastAfricanRing-
mg Scheme rings, standardbiometricmeasurements weretaken andmoultandbrood
patch scoresnoted.
Results
Species list
Sixty-nine ofthe 94 possible species from Stuart's (1989) list were recorded at Nilo
FR (Table 1): most ofthosenotrecorded were species ofloweraltitudes. Thirty-four
out ofa possible 36 East Coast Escarpment montane forest species that occur in the
EastUsambaras,accordingtothelistofStuartetal. (1993),wererecorded.Non-forest
species recordedduringthis study are indicated in Appendix 1
Table 1. Listofallforest-dependent speciesrecordedinornearNiloFR. Altitudesofall
observations aregivenhere. Whereappropriate,thepercentageofcapturedindividuals in
breedingcondition (withfresh, fully developedandvascularizedbroodpatches (BP)of4
or5) is indicated. Systematics andnomenclaturefollowZimmermanetal. (1996)
Species Altitude(m) Comments
AfricanGoshawkAccipitertachiro below 1350
AfricanCrownedEagleStephanoaetuscoronatus below 1500
MountainBuzzardButeooreophilus 900-1500
AfricanHarrierHawkPolyboroidestypus below 1150
SouthernBandedSnakeEagleCircaetusfasciolatus 1100-1350
Ayres'sHawkEagleHieraaetiisayresii 1100-1500
ScalyFrancolinFrancolimissqiiamatus 1000 foundinthicketsoutside
forest
AfricanGreenPigeonTreroncalva below 1100
LemonDoveAplopelialarvata 1100-1500
OlivePigeonColumbaarquatrix 1350
Bronze-napedPigeonC.delegorguei 1000-1500
TambourineDoveTurturtympanistria 1000-1500
Fischer'sTuracoTauracofischeri 1000-1500
BarredLong-tailedCuckooCercococcyxmontanus 1200
EmeraldCuckooChrysococcyxcupreus 1200
YellowbillCeuthmocharesaereus 1200
UsambaraEagleOwlBubovosseleri 1250-1350
AfricanWoodOwlSthxwoodfordii 1200 onlyonerecord; 1994
Bar-tailedTrogonApalodermavittatum 1200-1500
Silvery-cheekedHombillBycanistesbrevis 900-1500
TrumpeterHombillB.bucinator below 1200
White-earedBarbetBuccanodonleucotis 1000-2250
GreenBarbetB.olivaceum 1000-1500
Montane avifaunaofMtNilo 5
Species Altitude(m) Comments
MoustachedGreenTinkerbirdPogoniulusleucomystax 1000-1500
[Golden-tailedWoodpeckerCampetheraabingonior
MombasaWoodpeckerC.m(?w/?a^5/ca 1200 sufficientcharacteristicsto
distinguishthetwospecies
werenotobtained;how-
ever,seeSeddonetal.
(1995. 1996)]
CardinalWoodpeckerDendropicosfuseescens 1100-1200
OliveWoodpeckerD.griseocephalus 1000-1350
AfricanBroadbillSmithorniscapensis 1200-1350
Green-headedOriole0/7o/w5c/i/o/oft'p/za/jw 1000-1300
BlackSaw-wingPsalidoprocneholomelas 600-1350
Pale-breastedIlladopsislUadopsisrufipennis 1350 33.3%inbreeding
condition
AfricanHillBabblerPseudlcippeabyssinica 1250-1350
Square-tailedDrongoDicninisludwigii 1200-1500
BlackCuckoo-shrikeCampephagaflava 1350
GreyCuckoo-shrikeCoracinacaesia 1100-1500
Stripe-cheekedGreenbulAndropadusmilanjensis 1000-1500 6.7%inbreedingcondition
Shelley'sGreenbulA.masiikuensis 1000-1500 7.5%inbreedingcondition;
beggingjuvobservedin
1996
LittleGreenbulA.vzm?5 1250-1500
Cabanis'sGreenbulPhyllastrephuscabanisi 1000-1500 20%inbreedingcondition
TinyGreenbulP.debilis 1000-1400 racealbigula: 12.5%in
breedingcondition
Yellow-streakedGreenbulP.flavosthatm 1100-1500 40%inbreedingcondition
White-chestedAletheAlethefuelleborni 1250-1350
Spot-throatModulatrixstictigula 1250-1500
White-starredForestRobinPogonocichiastellata 1100-1500
Sharpe'sAkalatSheppardiasharpei 1000-1500 inbreedingcondition
OliveThrushTurdusoUvaceus 1250-1500
OrangeGroundThrushZootheragurneyi 1250-1500
Black-headedApalisApalismelanocephala 1000-1500
Long-billedApahsA.moreaui 1200-1250
Bar-throatedApalisA.thoracica 1200-1500 25%inbreedingcondition
EvergreenForestWarblerBradypteruslopezi 1000-1500
Grey-backedCamaropteraCama/oprera/?rac/23'Mra below 1250 100%inbreedingcondition
Red-cappedForestWarblerOrthotomusmetopias 1000-1500 75%inbreedingcondition
[SouthernHyliotaHyliotaaustralis 900-1200] uncertainidentitydueto
inadequateobservations;
however,seeSeddonetal.
(1995)
Yellow-throatedWoodlandWarbler
Phylloscopusruficapilla 1100-1500 3%inbreedingcondition
DuskyFlycatcherMuscicapaadiista 600-1250
ForestBatisBatismixta 1100-1350
PaleBatisB.soror below 1300
White-tailedCrestedFlycatcherTrochocercusalbonotatus 1000-1500 14.3%inbreeding
condition
VdiXdi6.\SQ¥\yc2Xc\iQ.rTerpsiphoneviridis below 1300
Black-frontedBushShrikeMalaconotusnigrifons 1000-1500
Waller'sStarlingOnychognathuswalleri 1000-1500
Kenrick'sStarlingPoeopterakenricki 1000-1500
CollaredSunbirdAnthreptescoUaris 1000-1250
UluguruViolet-backedSunbirdA.neglectus 1000-1250
6 NorbertJ. Cordeiro
Species Altitude(m) Comments
AmaniSunbirdA.pallidigaster 1000 October1996
BandedGreenSunbirdA.rubritorques 1000-1350
EasternDouble-collaredSunbirdNectariniamediocris 11^2r0\f0\-115cr0\f0\ 33.3%inbreeding
condition
OliveSunbirdA^.olivacea 600-1500 30.6%inbreeding
condition
YellowWhite-eyeZosteropssenegalensis 900-1500
Dark-backedWeaverPloceusbicolor 1000-1500
TanzaniaMountainWeaverP.nicolli 1250
Red-facedCrimson-wingCryptospizareichenovii 1200-1500 14.3%inbreeding
condition
Mist-netting
Table 2. Listofspeciesnetted ateachsiteinNiloFR. Capturerates [numberofbirdsper
5000net-metre-hours (number/nmh)] aregivenforcomparativepurposes
Species 1 (1350m) 2(1450m) 3(1500m) 4(1250m) Total
n(/?/nmh) /;(n/nmh) n(n/nmh) n(n/nmh) n(/?/nmh)
LemonDove 1 (1.7) 1 (0.4)
TambourineDove 3(5.2) 3(1.1)
AfricanBroadbill 1 (0.7) 1 (0.4)
Square-tailedDrongo 1 (0.7) 1 (2.8) 2(0.7)
Pale-breastedIlladopsis 3(2.1) 3(1.1)
AfricanHillBabbler 2(1.4) 1 (2.5) 3(LI)
Stripe-cheekedGreenbul 7(4.9) 1 (2.8) 4(7) 3(7.6) 15(5.5)
Shelley'sGreenbul 18(12.7) 10(27.8) 7(12.2) 18(45.5) 53(19.3)
LittleGreenbul 1(1.7) 14(35.4) 15(5.5)
OliveMountainGreenbul 8(5.6) 4(11.1) 2(3.5) 6(15.2) 20(7.3)
TinyGreenbul 12(8.4) 12(30.3) 24(8.7)
Yellow-streakedGreenbul 1 (0.7) 1 (2.8) 3(7.6) 5(1.8)
White-chestedAlethe 3(2.1) 3(7.6) 6(2.2)
Spot-throat 4(2.8) 2(3.5) 2(5.1) 8(2.9)
White-starredForestRobin 1 (1.7) 1 (2.5) 2(0.7)
Sharpe'sAkalat 8(5.6) 4(11.1) 3(5.2) 5(12.6) 20(7.3)
NorthernOliveThrush 1 (0.7) 1 (2.8) 2(3.5) 4(1.5)
OrangeGroundThrush 1(1.7) 1 (2.5) 2(0.7)
Bar-throatedApalis 5(3.5) 3(8.3) 8(2.9)
EvergreenForestWarbler 4(2.8) 3(7.6) 7(2.5)
Grey-backedCamaroptera 1 (2.5) 1 (0.4)
Red-cappedForestWarbler 2(1.4) 3(8.3) 3(7.6) 8(2.9)
Yellow-throated
WoodlandWarbler 12(8.4) 7(19.4) 2(3.5) 4(10.1) 25(9.1)
ForestBatis 2(5.1) 2(0.7)
White-tailedCrestedFlycatcher 8(5.6) 2(5.6) 3(5.2) 1 (2.5) 14(5.1)
CollaredSunbird 3(7.6) 3(1.1)
EasternDouble-collaredSunbird 2(1.4) 3(5.2) 1 (2.5) 6(2.2)
OliveSunbird 12(8.4) 13(36.1) 4(7) 7(17.7) 36(13.1)
Red-facedCrimsonwing 4(2.8) 3(7.6) 7(2.5)
Montane avifaunaofMtNilo 7
Weringed304birdsof29speciesatNiloFRin 13 746net-metre-hours(seeTable2).
Themost frequently captured group ofbirds were the bulbuls. Sharpe's Akalat, Yel-
low-throatedWoodland Warbler, White-tailed Crested Flycatcherand Olive Sunbird
werealsorelatively abundant.
Red Data Book species
Twelve threatenedornear-threatened species are listedby Collaretal. (1994) forthe
East Usambaras. An additional four restricted-range species occurring in the Tanza-
nia-MalawimountainsEndemic BirdAreaarealsoknownfromthere (Stattersfieldet
al. in prep). Ofthese, we recorded six threatened or near-threatened and all four re-
stricted-range species in 1994 (Table 3). The Amani Sunbird was added in 1995 by
Seddon et al. (1996) and I recorded it again in 1996. Four ofthe five threatened or
near-threated speciesknownfromtheEast Usambaras which werenotrecordedfrom
the Lutindi area ofNilo FR (Sokoke Scops Owl Otus ireneae, Swynnerton's Forest
RobinSwynnertoniaswynnertoni. EastCoastAkalatSheppardiagunningiandPlain-
backed SunbirdAnthreptes reichenowi) are currently known only from lowland for-
m
estsbelow550 (Tye 1993,Evansetal. 1994,Hipkissetal. 1994,CambridgeTanza-
niaRainforestProject 1994,Cordeiro&Githiruinprep.).Thesespeciesmayconceiv-
ablyoccurinthelow altitudeforestintheNkombolapartofNiloFR. Thefifth,possi-
bly overlooked, species is the elusive Dappled Mountain Robin Modulatrix
orostruthus, known only from about 900-1100 m at Amani (Collar & Stuart 1985,
Stuart 1989) and up to c. 1700 m in the Ndundulus and Nyumbanitus, Udzungwas
(Dinesen a/. 1993).
Table 3. Status ofglobally threatenedandrestricted-range speciesoccurringintheEast
Usambaras andrecordedduringthis study
Species Category* Presenceat
NiloFR
SouthernBandedSnakeEagleCircaetusfasciolatus nt X
Fischer'sTuracoTauracofischeri nt* X
SokokeScopsOwlOtusireneae
UsambaraEagleOwlBubovosseleri X
Swynnerton'sRobinSwynnertoniaswynnertoni
EastCoastAkalatSheppardiagunningi V
Sharpe'sAkalatS.sharpei * X
DappledMountain-RobinModulatrixorostruthus
Spot-throatM.stictigula * X
Long-billedApalisApalismoreaui c* X
Red-cappedForestWarblerOrthotomusmetopias * X
Kenrick'sStarlingPoeopterakenrickii X
AmaniSunbirdAnthreptespallidigaster 1996
Plain-backedSunbirdA.reichenowi nt
BandedGreenSunbirdA.rubritorques V* X
TanzaniaMountainWeaverPloceusnicolli Y* X
Categories:c-critical;v=vulnerable;nt-near-threatened(afterCollaretal. 1994);
*speciesofgloballyrestrictedrange(Stattersfieldetal.(inprep.)).
8 NorbertJ. Cordeiro
—
Long-billed ApalisApalis moreaui Critical
Sclater (1931a) described this species from the type, obtained near Amani in 1930.
Thisrarespecies,whichcanbeverydifficulttolocate(Stuart 1989,inlitt.),wasappar-
entlynotrecordedthereagainuntil 1972byR.J. Stjemstedt(inCollar& Stuart 1985)
andsubsequentlyby Stuart& Button (1978),Turner(1978) andBrittonetal. (1984).
Stuart & Hutton (1978) netted an individual at the forest edge and obtained other
records of it in dense vines, occasionally some distance from the forest. They also
twiceobservedit inmixedfeedingparties. Tye (inCollaretal. 1994)didnotobserve
it (but may have heard it) in four years at Amani and the only recent documented
recordisthatofB.W. Finch (inCollaretal. 1994), wholocatedamaleatMongaTea
Estate in 1992.
This species was observed twice on 11 August in the Lutindi area, barely outside
NiloFRinvery disturbedPublic Land forest. The firstrecord (1200m) was ofabird
foragingaloneinthedensetanglesofatreeabout3-4moffthegroundatabout 12:30,
just after a short showerofrain. The second individual was observed at about 16:00,
closeto aridge in adisturbedglade at 1250m. Itwas watchedgleaning invertebrates
fromaclumpofshrubsatground-levelindirectsunlightforseveralminutes,approxi-
mately 3-5 m from me. Both observations contradict the statement of Sclater &
Moreau (1932-33)thatthe speciesisnotfoundin sunlitplaces,butarenotincompat-
ible with thoseofStuart & Hutton (1978).
Physical features that helped distinguish this species from the local grey-headed
form of Black-headed Apalis included the shorter tail, faint wash ofbrown on the
greyish wings, brown tinge on the forehead andthe ratherthin, long bill. The behav-
iour of both individuals (alone in understorey vegetation, foraging by gleaning the
tangles andfoliage) is also indicative ofthis species.
Seddon etal. (1995, 1996) visited this areabut did notrecord this species atNilo
FRin 1995.ThissuggeststhatitiseitherextremelyrareorveryelusiveinNiloFRand
elsewhere inits range.
—
Usambara Eagle OwlBubo vosseleri Vulnerable
Thisrareowl isknownfromonly afew sites intheEastandWestUsambaras (Collar
et al. 1994) and, more recently, from the Uluguru mountains (Hunter et al. 1996).
ThereisalsoapossiblesightingintheNgurus(J.G.WilliamsinMoreau 1964).Itisan
elusive forest species, not recorded at Amani until 1969-73 (White 1974) and first
recorded in the West Usambaras in 1970 (Stuart & Hutton 1978). An individual was
capturedatKwamkoroFR(nearAmani)inAugust 1993(W.D.Newmarkinlitt,).The
totalpopulationwasestimatedatroughly500pairsin 1985(Collar&Stuart 1985),but
ismostlikelyhigherduetotherecentdiscoveryofpopulationsinthreeEastUsambara
lowlandforest sites (CambridgeTanzaniaRainforestProject 1994,Evansetal. 1994,
Evans 1997).
What was believed to be this species was recorded at Nilo FR on 9-10 August
(1250-1350m), where itcalledevery 2-5 min fromdense forestafterduskandfrom
about04:30-05:45.JacobKiure,whowasfamiliarwithitscall(seeEvansetal. 1994),
MontaneavifaunaofMtNilo 9
confirmeditasidenticaltothatheardinthelowlandsin 1992.1agreewithEvansetal.
(1994) that "there must remain a small degree ofdoubt thatthe call is ofthis species
until acallingbird is seen andtape-recorded simultaneously."
—
Tanzanian Mountain WeaverPloceus nicolli Vulnerable
Thetype specimen ofthis forestweaver, whichrangesfrom900-2200m inthe East-
emArc forests, was collected from Amani in the East Usambaras (Sclater 1931b). It
was subsequently recorded in the West Usambaras (Sclater & Moreau 1932-33,
Ripley & Heinrich 1966, Turner 1978, Stuart & van derWilligen 1979, Britton etal.
1984).
The Uluguru and Udzungwa subspecies anderseni was first collected by T.
AnderseninMay 1952(Franzmann 1983);furtherrecordsaresummarizedinCollaret
al. (1994). There is a possible recent record from the Rubeho Mountains (Fjeldsa &
Rab0l 1995).
A pair was seen outside the Nilo FR on 3 August at 1250 m in disturbed forest
whichformedpartofthePublicLand. They weregleaningepiphytes, asdescribedby
Dinesen et al. (1993), in the canopy some distance from a mixed-species flock. The
secondsightingwasoffourbirds on 11 Augustalongaridgenotfarfromtheoriginal
location. All four were perched in the canopy and observed through a 15-60x tel-
escope. In neither sighting was the species part of a mixed-species flock (see also
Dinesen etal. 1993) although other observers have noted them participating in such
flocks (Turner 1978, Stuart& vanderWilligen 1979, Brittonetal. 1984, Stuartetal.
1987). Seddon et al. (1995, 1996) also found this species in Nilo FR in a follow-up
visit.
TheserecordsfromMtNilo arethe firstfromtheEastUsambaras inover60years
(Cordeiro 1995),confirmingStuart's (1989)predictionthatitmightoccuratNiloFR.
Giventhe lack ofprevious observations, it appears to exist at very low densities (see
also Collar et al. 1994). It is therefore of utmost importance to safeguard the entire
montaneforestatNilo.
—
Banded Green SunbirdAnthreptes rubritorques Vulnerable
This sunbird is known from a number of Eastern Arc mountains, including the
Usambaras, Ulugurus, Ngurus and Udzungwas (Collar et al. 1994). It is common in
theEastUsambaras andthe south-western section oftheWestUsambaras, but scarce
elsewhere in its range (Collar & Stuart 1985, Collar et al. 1994). At Amani, it was
frequentlylocatedattheforestedgeandsometimesadjacentcultivation(Turner 1978,
Collar&Stuart 1985); ithasrecentlybeenreportedatlow altitude, 200m, intheEast
Usambaras(Hipkissetal. 1994,CambridgeTanzaniaRainforestProject 1994).Evans
(1997) noteditbreeding at300m.
In 1994, at least 25 observations, involving perhaps eight males and five females,
were made of this sunbird in the disturbed Public Land forest, especially near the
m
forest edge or in large glades. It was encountered from 1000-1250 and only once
m
observedat 1350 inthereserve. Seddonetal. (1995, 1996) alsorecordeditatNilo
FR in a follow-up survey. In 1996, a flock of about 10-15 individuals was located
10 NorbertJ. Cordeiro
feedinginalargefloweringtree withinthe same area(seenext species).
—
Amani SunbirdA.pallidigaster Vulnerable
Seddon etal. (1996) first recorded this bird inthereserve in 1995; I didnot find it in
1994. At least two males were observed in 1996 feeding alongside Banded Green
Sunbird, Olive Sunbird, Stripe-cheeked Greenbul, Shelley's Greenbul, White-tailed
Crested Flycatcherand Yellow White-eye in aflowering tree along aridge in Public
Landforest.
—
Southern Banded Snake Eagle Circaetusfasciolatus Near-threatened
This species has a wide but localized distribution in coastal forest from Somalia to
SouthAfrica(Collaretal. 1994). Itiscommon intheEastUsambaras (Moreau 1935,
Collar& Stuart 1985, Tye 1993), where there are recent reports ofitbreeding in the
lowlands(Hipkissetal. 1994,Cordeiro&Githiruinprep.).Itwasrecordedat 1250m
m
and 1350 in 1994.
—
Fischer's Turaco Tauracofischeri Near-threatened
AlthoughquitecommonintheEastUsambaras,itisapparentlyrareintheoutlyingMt
Mtai (Evans & Anderson 1992). At Nilo PR, it was frequently encountered from
m
1000-1500 whereit fedintheforestmid-storey andcanopy.
—
Spot-throatModulatrixstictigula Restricted-range
This species was considered common in the East Usambaras in the 1930s (Sclater&
Moreau 1932-33). Britton (1980), mentioned its decline there, probably basing this
commentontheobservations ofStuart& Hutton (1978) andTurner(1978), whosug-
gestedcompetition withM. orostruthus asthe cause. Thefactthatboth species occur
sympatricallyintheUdzungwas(Jensen&Br0gger-Jensen 1992,Dinesenetal. 1993)
weakens this suggestion. A likelier explanation is forest loss in the Amani area, the
best-surveyedpartoftheEastUsambaras, overtheyears. Newmark{inlitt. 1995, see
alsoNewmark 1991), who has studied this species at MonganearAmani since 1987,
observes that itis highly sensitiveto forestdegradation.
ItwasquitecommonatLutindi,NiloPR, whereeightindividuals wereringedand
several more heard. Although capture rates indicate that this species was relatively
common indisturbed forest (seeTable 2), theseresults arepotentiallymisleadingbe-
cause additional individuals were caught but escaped from the nets at sites 1-3. It
appeared to be especially abundant in the wet, undisturbed forest where more indi-
viduals wereheardcalling than in thedisturbedforestofthePublic Land.
—
Sharpe'sAkalatSheppardia sharpei Restricted-range
Anabundantspeciesfrom 1000-1500mandsomewhattolerantofhabitatdisturbance
(seeTable2).
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Red-capped Forest Warbler Orthotomus metopias Restricted-range
ThemostrecentEastUsambararecords ofthis warblerarethose ofNewmark(1991)
who netted only two birds in more than 59 000 net-metre-hours in July 1987. Stuart