Diversity of food of the Grey Parrot Psittacus erithacus in Korup National Park, Cameroon

4 Pages·2003·2.1 MB·

by  S A Tamungang

Diversity of food of the Grey Parrot
Psittacus erithacus in Korup National Park, Cameroon
S.A. Tamungangf andS.S. Ajayib
DesdonneesconcernantlanourritureduPerroquetgrisPsittacuserithacusontetecollecteesdansleParcNational
deKorupetsesenvirons,lelongdetransectsdansdesformationsforestieresprimaireetsecondaire.L’etudeaetabli
queleperroquetmangeles bourgeons, fleurs, fruits etgraines de 14 especes d’arbres appartenanta 13 families
differentes.Lavegetationsecondaireetaitplusricheennourriturequelaforetprimaire.Chaquemoisdel’annee
lePerroquetgrisdisposed’aumoinstroissourcesd’aliments,64%desalimentsatteignantleurmaturiteaucours
delasaisonsecheet36%ensaisondespluies. Poursurvivreal’etatsauvage, l’especeabesoind’alimentsdivers.
Sacapacitedediversifiersessourcesdenourritureenfonctiondessaisonsetdeshabitatsacontribueasonsucces
dans l’ecosysteme de la foret dense de Korup. Les resultats de l’etude permettront de diversifier le regime
alimentairedesPerroquetsgrisencaptiviteetdemieuxcomprendreleroledel’especedanslachainealimentaire
de Korup.
Fooditems differin nutritivevalueandavailability. In SupportZoneSample Plotislocatedin thesupportzone
the wild, foods occur patchily7 and a productive ofKNPandcomprisesheterogeneous andsecondaryveg-
,
habitatmayhavemany(orfewer)patcheswithgreaterfood etation, the result ofdiverse socio-economic activities. It
production. MostAfrican parrots feedpredominantlyon consistsofhumansettlements,farms,fallowedfarms,hunt-
plantmaterials,mainlyfruitsand/orseeds5,althoughafew ing and lumbering sites, service roads, and small-scale
arepartiallyreliantoninsects7.While,forinstance,Puerto plantations ofcocoa, coffee and oil palms. The habitat is
RicanParrotAmazonavittataisknowntofeedonc60plant patchy as the result ofland exploitation, and secondary
speciesinLuquilloForest9,littleisdocumentedconcerning forestindicatorspecies include Ceibapentandra,Musanga
the diversity offoods taken by the Grey Parrot Psittacus cecropioides Pycnanthusangolensis, Terminaliasuperbaand
,
erithacusinthewild3,6.Detailedknowledgeofthediversity T. ivorensis.
offoodstakenbytheGreyParrotisofutmostimportance
for restoring its degraded habitats in West and Central Materials and methods
Africa10. The present study aims to contribute to our Eachsampleplothasanareaofc4,500ha.Linetransects
understanding ofthe ecological role ofthe parrot in the (mean length 6km) were randomlyestablishedinthese
Korup forestecosystem, andpredictions ofthelikelihood tomonitorparrotactivity. Datawerecollectedbydirect
ofits presenceorabsence in thefoodchain in this area. observation ofparrots feeding. This involved walking
transects and searching areas of fruiting trees where
Study area birds might be feeding2 their presence being indicated
,
Koruprainforestinsouth-westCamerooncomprisesKorup by the species’ usual noisy behaviour at feeding sites.
National Park and its Support Zone (KNP). The park When a feeding parrot was located, information was
extendsfrom04°54’Nto05°28’Nand08°42’Eto09°16’E, recorded, and food remains andwhole food itemswere
andcoversanareaofcl25,000ha. Itliesintheevergreen collected for further examination and identification by
forest zone ofwet coastalWestAfrica, being classified as aplanttaxonomist. Datawerecollectedduring 1994 to
lowlandrainforestoftheGuinea-Congotype8 Ourstudy 1996.
.
wasundertakeninthesouthernpartofKNP;comparative
datawerecollectedintwosampleplotsdefinedasfollows: Results
Fooddiversity
Park Sample Plot is bounded to the south by Pamol Several food types, belonging to 13 families and 14 tree
Plantation,anagro-industrialoilpalmestate.Itisdominated species,weretakenbyGreyParrotinthestudyarea.Two
byprimaryvegetation; the indicator tree species include: foodtypeswereofthefamilyCaesalpinaceae, anothertwo
Enantia chloranta, Afzelia bipindensis, Strombosiopsis ofthefamilyBurseraceae,andtheotherfamilieswereeach
tetrandra,Obanguiaalata,Xylopiaaethiopicaaxi&Anthonotha represented byonetreespecies (Table 1). The birdswere
observedfeedingonbuds, flowers, fruitsandseeds. Inall,
threeflowersources(20%),fourseedsources(26.7%)and
seven fruit sources (33.3%) were identified. Information
DiversityoffoodoftheGreyParrotinKorupNationalPark: Tamungang&Ajayi BullABC Vol 10No 1 -33
4
4
was also obtained from secondary sources ofsix types of
food taken bytheGreyParrot (Table2).
Food distribution in sample plots
Tenfoodsources(74.3%)werefoundintheSupportZone
sample plot. Four food sources (25.7%) were present in
both plots (Table 1). The Support Zone appears to be
richer in food resources than the park itself.
A B Monthlyandseasonal distribution offood sources
Food typeswere furtherclassifiedbythe month in which
the part consumed by the parrot matured. There were at
leastthreematurefoodtypeseachmonth(Table3),fewest
5
in August, then June and September. March had the
Figures 1-5.FoodsoftheGreyParrotPsittacuserithacus(S.A. highest number of food sources (eight). There are two
Tamungang) majorseasons in the studyarea, thewet (April-October)
1. Elaeisguineensisvarietiesatdifferentstagesofripening(most anddryseasons(November-March).Basedonse%asonality,
preferredisD,whileleftoversofthefruitafterbeingeatenare thewetseasonhad35.9%andthedryseason64.1 offood
depictedinF) sources.
2. Pycnanthusangolensisyoungfruits(A=wholefruitsand
B=leftoversaftertheparrotshaveextractedthesoftseeds) Discussion
3. Albiziagummifera(A=wholefruits,B=seedseatenbyGrey Grey Parrot takes avariety offoods in Korup, including
ParrotandC§methodofseedextractionbyGreyParrot) over 14speciesoftreesandexploitingvariousplantparts.
4. Blighiawelwitschii(GreyParrotfeedsonthefawnarilattached InGhana,Dandliker recordedthespeciesfeedingonnine
totheseeds) treespecies. Itis known to feedon fruits andseeds inthe
5. DBi=alluefmtogvueirneseenesdes(heAll=s)seedseatenbyGreyParrotand wfoioldd.6 Tbuhtewpearrfootunaldsothfaetedfsloownerbsudrse4p.rAesesnttueddy2in0%Loboefkeit,s
34-BullABC Vol 10No 1 DiversityoffoodoftheGreyParrotinKorupNationalPark: Tamungang&Ajayi
Table 1. FoodspeciesoftheGrey ParrotPsittacuserithacusin Korup National Park, Cameroon, during 1994to 1996.
Tree species Family Partconsumed Dominantsample plot
Alstoniaboonei Apocynaceae Fruit SupportZone
Macaranga spinosa Euphobiaceae Fruit SupportZone
Danielliaogea Caesalpinaceae Flower SupportZone/Park
Dialumguineense Caesalpinaceae Seed SupportZone
Albizia gummifera Mimosaceae Seed SupportZone
Dacryodes edulis Burseraceae Fruit SupportZone
Dacryodes microphylla Burseraceae Fruit SupportZone
Elaeisguineensis Palmae Fruit SupportZone
Pycnanthus angolensis Myristicaceae Fruit SupportZone
Blighia welwitschii Sapindaceae Fruit SupportZone/Park
Spathodea campanulata Bignoniaceae Flower SupportZone
Ceibapentandra Bombacaceae Seed/Flowerbud SupportZone
Symphonia globulifera Guttiferae Flower SupportZone/Park
Treculia africana Moraceae Seed Support Zone/Park
south-east Cameroon, revealed that the GreyParrot con- diversity and not scarcity. The ability of the species to
sumesweeds, herbsandsoil1. diversifyitsfoodresourcesseasonallyhascontributedtoits
The availability ofseveral food sources each month variedfeedingbehaviourin Korup.
may ensure a balanced diet of nutrients for the parrot. Socio-economicactivitiesatKNPhaveresultedinthe
Seasonaldietshifts,causedbytheabsenceofpreferredfood growth of secondary vegetation that has enhanced the
types,werenoted. Forexample, duringseasonswithpoor
plumyield, theparrots consumemoreMacarangaspinosa
and Elaeisguineensis. Some tree species fruit longer than Table2. UnconfirmedfoodspeciesoftheGrey Parrot
othersinthesamehabitat,egSymphoniaglobuliferaproduces Psittacuserithacusin Korup National Park, Cameroon.
flowers over seven months of the year. Varied fruiting
phenologies provide different fruits year-round. Food Tree species Family Part
consumed
availability changes seasonally, according to phenology Afzelia africana Caesalpinioideae Bud
andrenewal rate11. Strephonema pseudocola Combretaceae Seed
Oilpalmfruitsareavailabletotheparrotsyear-round Sterculia tragacantha Sterculiaceae Seed
andthePamolplantationisimportantinthisrespect.Fruit Strychnos spinosa Loganiaceae Seed
arethemostfrequentlytakenfoodsofthespecies6 ‘Crunch Eribroma oblongum Sterculiaceae Seed
. Terminalia glaucescens Combretaceae Seed
periods’orcriticalseasonsforfoodmayresultfromreduced
Table3. MonthlypresenceoffoodsoftheGreyParrotPsittacuserithacusinKorupNational Park,Cameroon.
Treespecies Monthlyfoodpresence
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Alstonia boonei * * * * *
Macaranga spinosa * * *
Daniellia ogea * * *
Daliumguineese * *
Albizia gummifera * * *
Dacryodes edulis * * * *
Dacryodes microphylla * * * *
Elaeisguineensis * * * * * * * * * * * *
Pycnanthus angolensis * * * *
Blighia welwitschii * * *
Spathodea campanulata * * * *
Ceibapentandra * * * * *
Symphonia globulifera * * * * * * *
Treculia africana * *
Total numberoffoodsources 5 7 8 6 5 4 5 3 4 5 5 5
DiversityoffoodoftheGreyParrotinKorupNationalPark: Tamungang&Ajayi BullABC Vol 10No 1 -35
availabilityoffoodsourcesfortheparrot.Foodavailability 7. Krebs,J.R.andDavies,N.B.(eds) 1981.AnIntroduction
is also related to the phenological processes ofthe plants to Behavioural Ecology. Oxford: Blackwell Scientific
comprisingthevegetationcommunities;mostoftheplants Publications.
MPRD
shed their leaves in the early dry season. Some, eg Ceiba 8. 1989. Planfor the Development ofthe Korup
pentandra, produce flowers and buds when the leaves are NPaltainonnianlgP&arRkeagniodniatlsSDuepvpeolrotpZmoennet..Douala: Ministryof
shed.Theparrotfeedsonthebudsandsubsequentlyonthe
seeds,ensuringmaximumexploitationofthefruitingtree. 9. Snyder,N.F.R,Wiley,J.W.and Kepler,C.B. 1987. The
ParrotsofLuquillo:NaturalHistoryandConservationofthe
Puerto Rican Parrot. Los Angeles: West Found. Vert.
Conclusion
Zool.
Fourteentreespeciesbelongingto12familieswereidentified 10. Tamungang S.A. 1996. The vanishing Grey Parrots of
as foodsourcesoftheGreyParrot in KNP. Foodsconsist Cameroon: conservation prospects. Malimbus 18: 70-
ofbuds,flowers,fruitsandseedsbutonlytheoilpalmfruit 71.
isavailableallyear.Foodresourcesoftheparrotarepatchily 11. Wynne-Edwards, V.C. 1969. Feedback from food re-
distributed, and despite the species’ broad dietary sources population regulation. In: Watson,A. (ed)Ani-
preferences, availability can determine its diet at certain malPopulationRegulationtotheirFoodResources.Oxford:
periodsoftheyear.GreyParrotrequiresadiversityoffoods Blackwell Scientific Publications.
inKNP.TheSupportZoneisricherinfoodresourcesthan “DepartmentofAnimalBiology, UniversityofDschang, BP285
the park itself, but this hinders the species’ conservation Dschang, Cameroon.
&
becauseitisdifficulttocontrolparrotexploitationoutside departmentofWildlife FisheriesManagement, Universityof
thepark.Ourfindingsshouldbeusedtoimprovethefood- Ibadan, Nigeria.
degradedhabitatsoftheparrot,checknutrientdeficiencies
ofthespecies’dietincaptivity,anddevelopanunderstanding
ofthe roleoftheGreyParrot in the foodchain dynamics
within KNP.
Acknowledgements
FOREIGN BIRDWATCHING
V.S. Balinga, N. Songwe, A.A. Green, Z.E. Akum and
REPORTS AND
many others who have worked on the Korup Project
assisted SAT in many ways. Epkwe Kennedy made an INFORMATION SERVICE
excellent field assistant. RogerWilkinson ofChester Zoo
offeredvaluable technical assistance, and Keneth Usongo OrganisedbySTEVEWHITEHOUSE
andEstellaTamungangassistedatvariousstagesduringthe
manuscript preparation. rf
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