© Biologiezentrum Linz/Austria; download unter www.biologiezentrum.at Birds of La Gamba – a call for research and scientific collaboration Aves de La Gamba – un llamado para la investigación y colaboración científica Gerhard AUBRECHT & Christian H. SCHULZE Abstract:TheknowledgeoftheavifaunaoftheLaGambaregion,CostaRicaisstilllimitedandcloselyconnectedwiththefoun- dationoftheTropicalStationLaGamba.Specialattentionisdrawntothebiogeographicalsituation,birdconservation,endem- icbirds,thefaunisticinventoryandecologicalstudies.Existinggapsinourknowledgeandpossiblecontributionsbyongoingre- searchtoquantifyingtheimportanceofcountrysidehabitatstoactascorridorformovementsofforestbirdsareaddressed. Keywords:avifauna,ornithology,TropicalStationLaGamba,CostaRica,ornithologicalresearch. Resumen:ElconocimientoacercadelaavifaunadelaregióndeLaGamba,CostaRicaestáaunlimitadaoyestrechamenteco- nectadconlafundacióndelaestaciónTropicalLaGamba.Especialatenciónesdadaalasituaciónbioegeográfica,conservación deaves,avesendémicas,elinventariofaunísticoyestudiosecológicos.Seabordanlosclarosexistentesennuestroconocimiento ylasposiblescontribucionesdelasinvestigacionesencurso,almomentodecuantificarlaimportanciadeloshábitatruralespara actuarcomocorredoresdelmovimientodelasavesdelbosque. Palabrasclave:avifauna,ornitología,EstaciónTropicalLaGamba,CostaRica,investigacionesornitológicas. AcloselookontheavifaunaofLaGambareveals The area of La Gamba and the adjacent Golfo theincreaseofknowledgeduringthelast10to15years Dulceregionwasneglectedbyornithologistsforalong aswellasthegapsthatstillexist.Thethreecontribu- timeduringtheexplorationoftheCostaRicanavifau- tions about birds in this volume show different ap- na.Theareaisfarawayfromthecapitalcityandcen- proaches to this situation. Graham Tebb, the “guar- tralregionsandlackedanyresearchinfrastructurefora dian”oftheLaGambabirdlist(SAUBERERetal.2007), longtime.Incontrast,inotherareaslikeMonteverde meticulously describes the state of the bird inventory (NADKARNI & WHEELWRIGHT 2000), La Selva (MC- and presents an updated checklist for the area, which DADEetal.1994)andLasCruces(e.g.,BORGELLAJr.et outlinesrecentchangesindistributionareasanddocu- al.2001),whereresearchfacilitatedbyOTS(Organisa- mentsthestatusofrarities,migrantsandresidentbirds. tion of Tropical Studies) has a long history Christian H. Schulze and Isabell Riedl quantify in a (BURLINGAME2002),ornithologicalstudiesrepresenta comparative approach how countryside habitats con- substantial proportion of the local research activities tributetothehighregionalbirdrichness.Thisbaseline (e.g.,BLAKE&LOISELLE2000,SEKERCIO LUetal.2002, studyontheimportanceofdifferentlandscapecompo- 2007,WHEELWRIGHTetal.1984).AsoutlinedbyTEBB nents for maintaining bird species richness in the re- gion of La Gamba provides important information for (thisvolume)andAUBRECHT(thisvolume),collectors andprofessionalresearchersonlyvisitedtheregionvery theinterdisciplinarycorridorproject(describedinthis infrequently,resultinginverylittleandscatteredinfor- volume). Gerhard Aubrecht tries a museological ap- proach in describing the research history and the mationavailableontheavifaunaofLaGambaandits known museum specimens of the endemic black- vicinity(CHAVESetal.2005).Itwastheestablishment cheeked ant-tanager (Habia atrimaxillaris) in an exem- of the La Gamba Tropical Station in 1993 which fo- Stapfia88, plaryway.Inthisintroduction,wethereforewishonly cusedinterestonscientificstudiesincludingtheavifau- zugleichKatalogeder oberösterreichischen tohighlightsomeimportantaspects,withoutrepeating na of the region. The first ornithological publications Landesmuseen NeueSerie80(2008): thecontentsofthespecialcontributions. concerning La Gamba focused on hummingbird-plant 349-351 © Biologiezentrum Linz/Austria; download unter www.biologiezentrum.at interactions(KASTINGER&WEBER1999,2000).Apop- dynamic of bird assemblages, permanent bird census ular booklet (SAUBERER et al. 2007) about the birds of points should be established covering all the major theGolfoDulceregionprovidedsomefirstimpressions habitat types within the region (primary forest, forest of bird habitats and species richness, and the first pre- margin, gallery forests, and countryside habitats). The liminary checklist for the regional avifauna. The first resulting data could be used to quantify how temporal diploma theses with ornithological contents were re- dynamicofbirdassemblagesareaffectedbyhabitattype, cently completed (RIEDL 2008, SEAMAN in prep.). In changes in land use and the appearance of range-ex- 2001,GhiselleAlvoradovisitedtheareatocollectbirds pandingoreveninvasivespecies. fortheNationalMuseuminSanJosé.However,thepe- Acomparisonoftheavifaunaofexistingreserveson riod of ornithological research and documentation in the southern Pacific slope of Costa Rica with baseline theregionofLaGambaisstillveryshort.Therefore,it studies on population densities of endangered species seemsnecessarytopointoutexistinggapsinourknowl- wouldprovideimportantinformationabouttheextent edge and to emphasise the necessity for further studies towhichtheseprotectedforestareascomplementeach ontheregion’sbirdfauna.ThevicinityoftheTropical otheronaregionalscale. StationLaGambaoffersanopportunitytostudyforest bird communities in one of the last existing lowland Thearearepresentsoneofthelastremaininglarge rainforestareasonthePacificsideofCentralAmerica. blocks of evergreen lowland rainforest on the Pacific slopeofCentralAmerica,providingauniqueopportu- Biogeographically,theGolfoDulceregion–withits nity for synecological studies on bird communities of still remaining lowland rainforests – is described as iso- thisecosystemtype. lated in Costa Rica by JANZEN (1983), but better con- nected to the adjacent Panama. Historical and recent Furthermore,anintactgradientofforesttypesrang- land use transformed vast stretches of rainforest along ingfrommangroveandcoastalforesttolowlandrainfor- thePacificcoast,whichhadlargeimpactsontheavifau- est is available for studying differences in species com- na.ThenearbyOsaPeninsulaontheotherhandseems positionbetweenforesttypesandnichepartitioningof further isolated, being only connected by a relatively forestspecies. smallisthmus(KAPPELLEetal.2002).Inabroadersense, Thediverselandscapematrixoflowlandrainforest, theregionisinterestingasatransitionzoneandmelting riparianforeststripsandhuman-modifiedhabitatspro- potofbothnearcticandneotropicalavifaunas.Further- videsanopportunitytostudytheimportanceofdiffer- more, it is classified as the endemic bird area “South ent land use systems for maintaining species richness, Central American Pacific Slope” (STATTERSFIELD et al. particularlyofforestbirdsandendemicspecies,andin- 1998)andcontainsrecognisedareasforthreatenedbirds teractions between closed forest bird communities and in the neotropics (WEGE & LONG 1995), particularly adjacenthuman-modifiedhabitats.Whileforacertain “Rincón”,“Golfito”and“RíoCoto”withtheprotected fractionofforestbirds,countrysidehabitatsmayrepre- areas “Corcovado National Park”, “Golfo Dulce Forest sent ecological sinks or traps, certain land use systems Reserve”and“GolfitoFaunalRefuge”.Thus,theregion (e.g.agroforestrysystems)mayprovidevaluablesecond- isofoutstandingimportanceforbirdconservation.The ary habitats for others, or at least stepping stones for endemic birds and species with limited distributions of movementsbetweenforestfragments. specialinterestaredescribedbyTEBB(thisvolume). There are still many gaps in our knowledge about From the situation described above, some conclu- the autecology and biology of species. Breeding times, sions can be drawn about where future ornithological breedingecology,andseasonal(altitudinal)movements researchcouldfocus: still need to be studied. Especially interesting are the ThespeciesinventoryofLaGambaisstillfarfrom distinct Caribbean and Pacific distribution patterns of beingcomplete.Therefore,afurtherdocumentationof (sub)specieswhichmightrevealfurthernewsystematic birdrecordsfromtheareaishighlyrecommended.This results as recently shown with Cherrie’s tanager (Ram- wouldnotonlyimprovethecompletenessofthebirdin- phocelus costaricensis) and Passerini’s tanager (Rampho- ventory but would allow us to document temporal celuspasserinii). changesofbirdspeciescompositionandtheoccurrence Specialhabitatsliketheseacoast(marinebirdsand of individual species. Several species expanding their waders) and mangroves are still poorly investigated. rangesnorthwardsorsouthwardsalongthePacificslope Two species of special interest, the threatened and en- have recently reached La Gamba and others will cer- demic mangrove hummingbird (Amazilia boucardi) and tainlyfollow. thethreatenedyellow-billedcotinga(Carpodectesanto- Foramoredetaileddocumentationofthetemporal niae)arerestrictedtomangrovehabitatsandneedspe- 350 © Biologiezentrum Linz/Austria; download unter www.biologiezentrum.at cialattention.Theconservationstatusofbothspeciesis MCDADEL.A.,BAWAK.S.,HESPENHEIDEH.A.&G.S.HARTSHORN(ed.) incompletelyknown.Moredetailedstudiesonthebiol- (1994):LaSelva.Ecologyandnaturalhistoryofaneotrop- icalrainforest.—Univ.ChicagoPress.ChicagoandLondon. ogyofsuchspecieswithhighconservationrelevanceare urgently needed to develop efficient conservation NADKARNI N.M. & N.T. WHEELWRIGHT (ed.) (2000): Monteverde. Ecologyandconservationofatropicalcloudforest.—Ox- strategies. Habia atrimaxillaris is another species with a fordUniv.Press.NewYorkandLondon. highconservationvaluetoithighlyrestricteddistribu- RIEDLI.(2008):GalleryforestsinthelowlandcountrysideofCos- tionrange(seeAUBRECHT,thisvolume).Therainforest taRica:Corridorsforforestbirds?—Diplomathesis,Univ. ofLaGambaholdsoneofthelastlargepopulationsof Vienna. thespecies,providingarareopportunitytostudyitslife SAUBERERN.,TEBBG.,HUBERW.&A.WEISSENHOFER(ed.)(2007):The historyandpopulationdensity. birdsoftheGolfoDulceregion,CostaRica.—Vereinzur FörderungderTropenstationLaGamba,Vienna. Seasonal movements directly lead to the problems EKERCIO LUC.H.,EHRLICHP.R.,DAILYG.C.,AYGEND.,GOEHRINGD.& oflandscapefragmentation.Whichspeciescanadaptto R.F.SANDI(2002):Disappearanceofinsectivorousbirdsfrom these changes and which populations act as ecological tropicalforestfragments.—Proc.Natl.Acad.Sci.USA99: sources or sinks? How do rapid and/or long-term 263-267. changes in land use influence bird communities? How EKERCIO LUC.H.,LOARIES.R.,OVIEDOBRENESF.,EHRLICHP.R.&G.C. dobirdcommunitiesandspeciesreacttotheestablish- DAILY(2007):PersistenceofforestbirdsintheCostaRican mentofecologicalcorridorsandhowcantheeffectsof agriculturalcountryside.—Conserv.Biol.21:482-494. natureconservationbemeasuredbymonitoringstudies? STATTERSFIELDA.J.,CROSBYM.J.,LONGA.J.&D.C.WEGE(1998):En- demic bird areas of the world. Priorities for biodiversity Allthesequestionsoffermanypossibilitiesforfuture conservation.—BirdLifeConservationSeries7:1-846. ornithological research in the La Gamba region. The WEGED.C.&A.J.LONG(1995):Keyareasforthreatenedbirdsin TropicalStationLaGambaoffersanincreasinglyuseful theneotropics.—BirdLifeConservationSeries5:1-311. infrastructure, a scientific focal point and a starting WHEELWRIGHTN.T.,HABERW.A.,MURRAYK.G.&C.GUIDON(1984): point for ornithological investigations. Any scientific Tropicalfruit-eatingbirdsandtheirfoodplants:asurveyof collaborationisverywelcome. aCostaRicanlowermontaneforest.—Biotropica16:173- 192. References BLAKEJ.G.&B.A.LOISELLE(2000):Diversityofbirdsalonganele- vationalgradientintheCordilleraCentral,CostaRica.— TheAuk117:663-686. BORGELLAR.,SNOWA.A.&T.A.GAVIN(2001):Speciesrichnessand pollen loads of hummingbirds using forest fragments in SouthernCostaRica.—Biotropica33:90-109. BURLINGAMEL.J.(2002):EvolutionoftheOrganizationforTropi- calStudies.—Rev.Biol.Trop.50(2):439-472. CHAVESJ.,BARRANTESG.&A.PEREIRA(2005):LaavifaunadeGolfi- to.—In:LOBOJ.&F.BOLANOS,HistorianaturaldeGolfito, CostaRica.SantoDomingodeHeredia,INBio:215-228. HACKETTS.J.(1996):MolecularPhylogeneticsandBiogeography ofTanagersintheGenusRamphocelus(Aves).—Molecu- larPhylogeneticsandEvolution5(2):368-382. Addressesofauthors: JANZEN D.H. (ed.) (1983): Costa Rican natural history. — Univ. GerhardAUBRECHT ChicagoPress.ChicagoandLondon. BiologyCentre,StateMuseumofUpperAustria KAPPELLE M., CASTRO M., ACEVEDO H., GONZÁLEZ L. & H. MONGE J.-W.-Klein-Straße73 (2002):EcosistemasdelÁreadeConservaciónOsa.—Serie A-4040Linz/Austria EcosistemasdeCostaRicaII.SantoDomingodeHeredia, E-mail:[email protected] INBio. KASTINGERC.&A.WEBER(1999):Attractionofhummingbirdsby ChristianH.SCHULZE extrafloralcuesinsomeCostaRicanspeciesofColumnea DepartmentofPopulationEcology (Gesneriaceae).—14.Symp.Biodiv.Evolutionsbiol.,Jena: FacultyofLifeSciences 94. UniversityofVienna KASTINGERC.&A.WEBER(2000):Attractionofhummingbirdsby Althanstraße14 extrafloralcuesinsomeCostaRicanspeciesofColumnea A-1090Vienna,Austria (Gesneriaceae).—LinzerbiologischeBeiträge32(2):652- 653. E-mail:[email protected] 351