Populationand Social Characteristicsof the Tamarao (Bubalus mindorensis)1

David W. Kuehn2 U.S. Peace Corps, PhilippineBureau of Forest Development,Quezon City,Republic of the Philippines

ABSTRACT A minimumof 51 tamarao (Bubalus mindorensis)occurred in a 20-km2study area at the Mt. Iglit Game Refuge and Bird Sanctuary,Occidental Mindoro, the Philippines.Juvenile bull tamaraoformed groups similarto those in juvenilewater buffalo (Bubalus bubalis),but adult tamaraodid not formclans or aggregationslike buffalo.

THE TAMARAO WAS KNOWN long beforeit was described STUDY AREA (Heude 1888, Steere 1888), but it frequentlywas con- fusedwith the anoa (Bubalus [Anoaj depressicornis,Bu- The studyarea lies in thefoothills of the mountainrange balus IIAnoa1quarlesi) (Everett 1878). Taxonomistsnow thatruns through Mindoro's interior and includes20 km2 agreethat the tamarao is a memberof thegenus Bubalus, of the Mt. Iglit Refugeeast of the refugeheadquarters. but Bohlken (1958) consideredit a subspeciesof the Elevationranges from 300 to 1000 m. Most of thestudy waterbuffalo, and Groves(1969) morerecently accorded area is comprisedof severalridges, and it is bounded by it specificstatus. rangesof steepridges to the north,east, and south.Two Although tamarao occurredon Luzon during the riversflow year round and severalstreams flow only in Pleistocene(Beyer 1957), duringhistoric times they have the rainyseason. beenrestricted to theisland of Mindoroin thePhilippines. Grasslandcovers 90 percentof the studyarea, and Tamarao have been legally protectedsince 1936, but threegrassland types are verycommon. Talahib (Saccha- Harper (1945) warnedthat the species faced earlyex- rumspontaneum) dominates the wettest areas in standsup tinctionprimarily due to habitatdestruction and poach- to 4 m high.Cogon (Imperataspp.) dominatessomewhat ing. Numberingperhaps 10,000 in 1900 (Harrisson dryerareas. A complexof shortergrasses, including The- 1969a), thetamarao population decreased to about 1000 meda spp., Paspalum spp., and Alloteropsissemialata, in 1949 and 244 in 1953 (Manuel 1957). By 1969 only dominatesthe upperslopes of the ridges.Reeds (Phrag- 100 tamarao were believed to inhabit four regionsin mitesspp.) occur along the rivers.Bamboo (Dinochloa Mindoro(Harrisson 1969b, Alvarez 1970). spp. and Schizostachyumspp.) and secondarydipterocarp The 90-km2Mt. Iglit Game Refugeand Bird Sanc- forestsoccur along the rivers and whereverthe topography tuarywas establishedin one of the fourMindoro regions causes a firebreakeffect (Talbot & Talbot 1966, Philip- in 1961 and was enlargedto 755 km2in 1969. Talbot pine Bureauof ForestDevelopment, pers. comm.). Mem- and Talbot (1966) estimateda minimumof 17 tamarao bers of the Batangan tribeburn most of the grassland survivedat Mt. Iglit in 1964; fiveyears later Harrisson everydry season. The studyarea has a dryseason from (1969b) estimatedat least 20 remained. December throughMay and a rainyseason fromJune This paper offerscriteria for estimatingthe age of throughNovember. Rainfall averages 300 cm annually tamaraoin thefield, documents population characteristics in OccidentalMindoro (Landicho 1952). of tamarao on a 20-km2 study area at Mt. Iglit, and comparesthe behavior of tamarao, whose range was heavilyforested before human arrival(Landicho 1952, METHODS Wernstedt& Spencer1967), withthat of thewater buf- Field workwas conductedon 221 days during3-7 May falo, which is adapted to more open habitat (Halder 1972, 3 September1972 through18 July 1973, and 4 1973). November1973 through22 March 1974. Areasaround vantagepoints were scanned with binoculars and spotting scopeto observetamarao. Adult (olderthan 5 years)cow tamaraowere individuallyidentified by hornconforma- i Received 22 October 1984, revisionaccepted 16 April 1985. tion and the and sex of theircalves. 2 Presentaddress: Forest Wildlife Populations and Research by number,age, Group,Minnesota Department of Natural Resources, 1201 East Most adult bulls could not be individuallyrecognized, Highway2, Grand Rapids, Minnesota55744, U.S.A. and the estimateof theirnumbers is based on timesand BIOTROPICA18(3): 263-266 1986 263 areasof observations.In examininggroup size tamarao TABLE 1. Sex and estimatedage of tamaraoobserved during werecounted once during each day they were observed. December1972-May 1973.

Unknown RESULTS Age in years Bulls Cows sex AGINGCRITERIA.-Provisional criteria were developed to 0.5 0 1 5 estimateage of tamarao from pelage color and from horn 1.5 1 2 1 lengthand conformation.A neonate tamarao was red- 2.5 4 2 0 3.5 3 2 0 dish-brownwith dark brown legs and a blackdorsal line. 4.5 1 3 0 Calvesa fewmonths old had lightbrown bodies which 25.5 16 10 0 laterturned dark brown or a slatecolor. A captivecow Total 25 20 6 andbull developed slate-colored pelage at 3-4 yr(J. M. Buenaflor,pers. comm.). In mostanimals the slate-col- oredpelage darkened to black,but three adult cows were brownor brown-tinged.Two bullsturned black a year Two bulls were 3-4 yrold and two were4-5 yr old in afterthey developed slate-colored pelage. January-July1973. In that period only 4 (18%) of 22 Observationsof horngrowth in cow tamaraowere observationsof thegroup were of lone animals,compared madeon onecalf from the age of a fewdays to 9 months, to 8 (47%) of 17 observationsfrom November 1973 andon twoothers from age 1 to 2 yrand from 3 to 4 yr. throughMarch 1974. The age of thesecond calf was estimatedby comparing Cow tamaraowere alone or accompaniedby up to herhorn growth to thatof thefirst calf, and theage of threecalves in 71 (66%) of 107 observations,and were thelast calf was establishedwhen it developedslate-col- withbulls in 33 (31%), 4 of them involvingcourtship. oredpelage at an assumedage of 3.5 yr.At an assumed Only one recurrentassociation between adult cows was age of 1 yrthe second calf's horns reached the middle of observed:two cows, each with one calf,were seen together herears when the ears were parallel to them;at 2 yrof 6 timesand separatetwice over 16 months.In the only age herhorns reached two-thirds of thedistance to the otherassociations, a cow withthree calves was seen once eartips. The horns of the oldest calf were longer but still witha calflesscow, and a cow withone calfwas briefly spike-likeat 3 yr,and at 4 yrthey started to broadenat associatedwith an adult bull and threejuvenile bulls. thebases, approaching adult conformation. Fiveyoung tamarao calves were seen, including a neo- At 2 yrof age,estimated from pelage changes, the nate on 2 June 1973 and one estimatedat 1-2 weeks hornsof twobulls reached their ear tips.At 3 yrtheir old on 18 October 1972. The birthdatesof threecalves hornsextended past the ear tips, and in one animalthe seen in November 1972 and 1973 were estimatedas basesof thehorns were broadening. At 4 yrof age the beingin August-September,so birthsmay occur through- hornsof both bulls were wedge-shaped with broad bases out Mindoro'sJune-November rainy season. In the only andnarrow terminal halves. The horns of two other bulls prolongedobservation of a neonate,a tamaraocow grazed werestill wedge-shaped at 5 yrof age, estimatedfrom 50 m away whilethe calflay withher neck stretched on pelagechanges. theground, a posturetypical of the "hider" species(Lent 1974) whichhide theiryoung rather than accompanying POPULATIONESTIMATE.-Fifty-one different tamarao were themconstantly. countedduring the December-May dry season of 1972- The oldest male calves still in familygroups were 1973 (Table 1). The sexratio was approximatelyequal estimatedto be 3 yr old, and two apparentlyindepen- (9 males:10females) among tamarao not more than 4.5 dentmales were2 yrold. Female calvesup to 4.5 years yrold. If the number of adult cows equalled the estimated old (Table 2) were observedin familygroups, and two 16 adultbulls, and if theyaveraged 1.6 calvesat heel femalesappeared to be independentat 1.5 and 2.5 yr (Table 2), a minimumof 67 tamaraooccupied the 20- of age; anotherfemale was drivenoff by her motherat km2 studyarea. 3.5 yr.

SOCIALCHARACTERISTICS.-Adult bull tamaraowere large- AGONISTIC BEHAVIOR.-No fightsbetween bull tamarao lysolitary. Of 218 observations,179 (82%) wereof lone wereobserved, but 8 pursuitsof one bull by anotherwere bulls,33 (15%) wereof bullswith cows, and 5 (2%) seen. One incidentoccurred 2 hr afterbreeding activity wereof bullswith independent tamarao less than4 yr was observednearby, but the cow was not presentwhen old. The largestaggregation observed included an adult the bulls came intoconflict. Four incidentsoccurred after bull,a cowand calf,and threebulls not more than 3.5 fireshad clearedmost of the cover froman expanse of yrold. grasslandand the tamarao had convergedon the un- Fourjuvenile tamarao were frequently seen together. burned areas. In 2 incidentsan adult bull chasedoff two 264 Kuehn buf- TABLE 2. Sex and estimatedage ofoffspring accompanying cow Adult tamaraoare much less social than water tamaraoduring December 1972-May 1973. falo. Associationsof adult bull tamarao were not ob- served,and in 8 incidentsbull tamaraowere observed Cow Sex and estimatedage ofcalves purusingother bulls, indicatingthat the absenceof ag- 1 gregationsis not due solelyto the small remainingpop- 2 ulationof tamarao.Only 1 recurrentassociation of cow 3 f-0.5 tamaraowas observed.In contrast,bull buffalomay form 4 ?-O.5 groupsof up to 50, and generationsof cow buffaloform 5 ?-1.5 6 ?-0.5 f-4.5 clans numberingup to 30 animals.The clans may com- 7 f-1.5 f-4.5 bine in herdsof up to 500 buffalo(Tulloch 1978). The 8 ?-0.5 m-1.5 m-2.5 group of 4 juvenilebulls observedwas similarto the 9 ?-0.5 m-2.5 f-4.5 groups2- to 3-year-oldbull buffaloform after they are 10 ?-0.5 m-2.5 f-4.5 expelledfrom family groups (Tulloch 1979). m = male. f = female.? = unknownsex. Numeral = age in Male tamaraoolder than 3 yrand femalesolder than years. 4.5 yearswere not observedin familygroups. An adult bull tamarao attacked a 2.5-yr-old male calf which mounteda cow; thisbehavior is similarto thatin buffalo, juvenileswhich had moved beyondtheir previously ob- wherean adult bull drivesoff 2- to 3-yr-oldmales when servedrange. In the onlyincident observed in itsentirety, a cow in the clan is in estrus(Tulloch 1979). A cow one bull pursuedanother for 1 km afterencountering it tamaraowas observeddriving off her 3.5-yr-oldfemale unexpectedlyin densecover. The observedportions of the calf, indicatingthat the small size of tamarao family otherpursuits were also long, rangingfrom 100 to 700 groups,compared to the buffalo'sdans, is activelymain- m and averaging300 m. tained.The observationof a tamaraocow grazing50 m Tamarao were not observedto use earthtossingor fromher neonatealso indicatesthat a differentcow-calf verticalhead movementsas threatslike those Tulloch relationshipoccurs in tamarao than in buffalo;buffalo (1978) observedin water buffalo.In 6 incidentscow cows do not range that far fromtheir calves until the tamaraoexpressed threats by loweringtheir heads with thirdmonth (Tulloch 1979). the hornsnearly vertical and shakingthe hornslaterally, The lessersociability of tamaraothan of buffalomay similarto the threatposture in domesticcattle (Hafez & be an adaptationto a foresthabitat (Eisenberg 1966), in Schein 1962). One cow chased her calf and hornedit contrastto buffaloes'adaptation to more open habitat severely,another prodded a calf with her horns,and a (Halder 1973). The social characteristicsof the tamarao thirdlowered her head withhorns vertical and walked at may resemblethose of the anoa, anotherpoorly known a calf. forestbuffalo, but thetamarao is moresolitary than other bovines(Nowak & Paradiso 1983). DISCUSSION ACKNOWLEDGMENTS The populationdensity at Mt. Iglit,at least 51 tamarao on the 20-km2 studyarea, should not be appliedto other I thank T. K. Fuller,Minnesota Department of Natural Re- areas because much of Mindorois veryrugged and un- sources,for reviewing the manuscript,and J. B. Alvarez,Phil- ippineBureau of Forest Development, and thestaff of theMt. suitableas tamaraohabitat. Also, few areas are as well IglitGame Refugeand Bird Sanctuary,for supporting this study. protectedagainst poaching as the studyarea, whichhas The studywas fundedby the U.S. Peace Corps-Smithsonian had residentgame wardenssince 1969. The age structure InstitutionEnvironmental Program and the PhilippineBureau of thetamarao population suggests the herd has increased ofForest Development. steadilysince then.

LITERATURECITED ALVAREZ, J. B., JR. 1970. Philippinetamaraw: here to stay.IUCN Publ. N. S. 18: 46-51. BEYER, H. 0. 1957. New findsof fossilmammals from the Pleistocenestrata of the Philippines.Natl. Res. Counc. Philippines Bull. 41: 220-239. BOHLKEN, H. 1958. Vergleichendeuntersuchungen an wildridern(Tribus Bovini Simpson 1945). Zool. Jahrb.(Phys.) 68: 113- 202. EiSENBERG, J. F. 1966. The social organizationsof mammals.Handb. Zool. 10: 1-92. EVERETT, A. H. 1878. Letter.Proc. Zool. Soc. London 1878: 792.

Characteristicsof the Tamarao 265 GROVES, C. P. 1969. Systematicsof the anoa (Mammalia, Bovidae). Beaufortia17: 1-12. HAFEZ, E. S. E., AND M.W. SCHEIN. 1962. The behaviourof cattle.In E. S. E. Hafez (Ed.). The behaviorof domesticanimals, pp. 247-296. Williams and Wilkins Co., Baltimore. HALDER, U. 1973. Ecologicalaspects of social organisationin banteng(Bos javanicus) and feralbuffalo (Bubalus bubalis)in Java. EleventhInt. Congr.Game Biol.: 159-164. HARPER, F. 1945. Extinctand vanishingmammals of the old world.Am. Comm. Int. Wildl. ProtectionSpecial Publ. No. 12, pp. 548-550. HARRISSON, T. 1969a. The tamarawand its survival.IUCN Bull. N. S. 2: 85-86. 1969b. The tamarawand Philippineconservation. Biol. Cons. 1: 317-318. HEUDE, P. M. 1888. Note sur le petitbuffle sauvage de lile de Mindoro(Philippines). Memoires concernant I'histoire naturelle de l'Empirechinois. 2: 4, 50. LANDICHO, M. Z. 1952. The Mindoroyearbook. Yearbook Publishers,Manila. LENT, P. C. 1974. Mother-infantrelationships in ungulates.In V. Geist and F. Walther (Eds.). IUCN Publ. N. S. 24, The behaviorof ungulatesand its relationto management,pp. 14-55. IUCN, Morges,Switzerland. MANUEL, G. C. 1957. Statusof tamaraw,Anoa mindorensis(Heude). Proc. EighthPacific Sci. Cong. 3A: 1463-1474. NOWAK, R. M., AND J. L. PARADISO (Eds.). 1983. Walker's mammalsof the world.Johns Hopkins Univ. Press,Baltimore and London. STEERE, J. B. 1888. Letter.Proc. Zool. Soc. London 1888: 413-415. TALBOT, L. M., AND M. H. TALBOT. 1966. The tamarau(Bubalus mindorensis[HeudeD). Observationsand recommendations. Mammalia 30: 1-12. TULLOCH, D. G. 1978. The waterbuffalo, Bubalus bubalis,in Australia:grouping and home range.Aust. Wildl. Res. 5: 327- 354. 1979. The waterbuffalo, Bubalus bubalis,in Australia:reproductive and parent-offspringbehavior. Aust. Wildl. Res. 6: 265-287. WERNSTEDT, F., AND J. SPENCER. 1967. The PhilippineIsland world.Univ. of CaliforniaPress, Berkeley.

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