Jan.] 37 1959a

THE IMPACT OF DEFOKESTATION ON BIKDS OF CEBU, PHILIPPINES, WITH NEW KECOKDS FOK THAT ISLAND

BY D. S. RABOR Cebu Island, in the central Philippines, is one of the ten large islandsof the archipelago,with an area of about 4390 squarekilo- meters. Though hilly, it reachesno great height, the maximum eleva- tion being 1013meters in Mr. Cabalasanin the central part. The islandwas probably originally forested. Before the comingof the Spaniards,in 1521,the populationprobably raised only rice as a food crop. This could be grown only on favorable areas in the narrow coastalplain. Thus deforestationwas limited. With the arrival of the Spaniards,and the introduction of corn, sweetpotato and cassava(all native to tropical America),which could be raised more widely on lowlandsand hills, deforestationcontinued. Within historictimes Cebu has been densely populated compared with nearby islands. Before populationpressure the forestsdisappeared. This deforestationwas hastened by the wastefulmethod of shiftingculti- vation (kaingin system)practiced, in which land is cleared,planted to cropsfor a few seasons,then abandonedfor a new clearing. When ornithological collectingwas started on Cebu in 1872, the forestswere limited to patchesin a few partsof the island. In 1906, when McGregor and his assistantscollected on Cebu, they already had difficultyin finding forestsin which to collect. For some decadesthe Bureau of Forestry has been carrying on reforestationprojects on Cebu, the most notable of thesebeing in Toledo and in the hills near the water reservoirof Cebu City at BuhisanDam. Up to 1941,the Bureau'sefforts were progressingand new forestswere being developed. The SecondWorld War broke out and when it endedin 1945,nothing much was left of the govern- ment-createdforests. The peoplehad clearedmost of them as well as the beginningluxuriant growthsin many placesin the hills and mountainsof Cebu. Today, the Bureau of Forestryis again very seriouslycarrying on reforestationwork in severalparts of Cebu. In our work from SillimanUniversity in Cebu,begun in 1947 (see below) and in aerialsurvey of the island,we havebeen unable to find any patchesof originalforest, and the bestbird area we found was the newlydeveloped forest near Buhisan Dam. ORN•O•.OGICA•. His•roR¾ oF CEBU Severalcollectors have worked on Cebu. Among them were A. B. Meyer in 1872, J. B. Steere (First SteereExpedition) in 1874-75, [- Auk 38 R^noR,Impact o! De[orestationon Birdso! Cebu I-Vol.76

J. Murray (ChallengerExpedition) in 1874,A. H. Everettin 1877, Secondsteere Expedition (J. B. Steere,F. S. Bourns,E. L. Moseley, D.C. Worcester)in 1888, Menage Expedition (F. S. Bournsand D.C. Worcester)in 1892,and R. C. McGregorin 1906. SinceMc- Gregor'swork on Cebu in 1906, no seriousornithological collecting hasbeen done on this island until 1947,when my students,assistants and I started to make collections of the land vertebrates on Cebu. One objectivewas to find out how the land vertebratefauna, espe- cially the birds, have fared in the face of the excessivedeforestation sufferedby this island during the twentieth century. In this study, Mr. Filomeno Erapeso,a Field Assistantof the Biology Department of Silliman University,has aided me very efficiently. Collectingwas carried on periodicallyin severalplaces on the island. To date about 1100bird specimens,among other land verte- brates,have been collectedon Cebu. The collectionsare at present in variousinstitutions, the bulk of them in the ChicagoNatural His- tory Museum (CNHM) and in Silliman University (SU), and a few in the Yale PeabodyMuseum (YPM). R. C. McGregor (1909. "A Manual of Philippine Birds,") lists 154 speciesfrom Cebu, of which 123 are resident,30 migrant, and 1 of doubtfulstatus. D.S. Rabor (1952. Auk, 69 (3): 253-257) added two new recordsof residentforms, raising the total to 156. The presentpaper reports 10 new bird recordsfor Cebu, which include 6 residentand 4 migrant forms. This raisesthe total number of birds known from Cebu to 166, of which 131 are resident, 34 migrant, and one of doubtful status. Of the 10 new records, 8 are representedby actualcapture of specimens,and two by sightrecords on various occasions. Three interestingaspects of the bird life on Cebu Island are dis- cussedbelow: a. the statusof the 10 endemicforms; b. forestspecies; c. new records. The vernacular names follow in general those in Delacour and Mayr, 1946,"Birds of the Philippines,"(MacMillan Co.). ENDEMIC FORMS Ten endemicforms (seelist below) have beenrecognized for Cebu. All presumablywere forest birds. We were able to find only one of these,the Black Shama,Copsychus cebuensis. The followingis a list of the endemicbirds with their presentstatus: Phapitreronamethystina Irontails Bourns and Worcester.Amethyst Brown Fruit Dove.--Collectedby Bournsand Worcester,1892, and not found sincethen. Pre- ferred hill and mountain original forests. •9•9a I•o•, Impacto)•De)•orestation onBirds o)• Cebu 39 Loriculusphilippensis chrysonotus Sclater. PhilippineHanging Parakeet.--Col- lectedby: Meyer,Steere, Everett, Steere Expedition (second), Menage Expedition, McGregor.Not foundsince McGregor collected it in 1906. The speciesprefers originalforests of the lowlandsand hills, but alsoranges in the coconutgroves and secondgrowth. Breeding,however, takes place in original forests,at the edgesof same,or in forestclearings. This speciesis one of the commonbirds that are kept as cagepets throughout the Philippines. However,in recentyears, the birds that I have seenon Cebu that werekept as cagebirds, were either the Mindanaorace, L. p. apicalis,or the Negrosrace, L. p. regulus. Both forms are very abundant in their home islands. Regularpeddlers bring them in boatsfrom Mindanaoand Negrosand sell them in Cebu City. Since 1947, I have not collected,nor definitely observed,the Cebu race of the species. On severaloccasions, however, I heard the very characteristicmusical notesof the speciesin the coconutgroves in southernCebu. But then, nobody can be sure of the particularrace of the bird that might be singingat any one time becausethe songsof the variousraces are similar. I heard the notesof the specieson Siquijor Island and thought that at last we would have the chance to collectthe rare Siquijor race,L. p. siquijorensis.The bird was collectedand to our amazement,it turned out to be L. p. regulus of Negros. It must have been a cageescape, one of many cagebirds of this speciesbrought over from Negros. Coracinastriata cebuensisGrant. Barred Graybird.--Collectedby: Everett, Bourns and Worcester,McGregor. Not found sinceMcGregor collected it in 1906. Preferred original forestsof the lowlands,hills and mountains,but also ranged in the secondgrowth. Coracina caerulescensalterurn Ramsay. Black Graybird.--Collectedby: Everett, Bourns and Worcester, McGregor. Not found since McGregor collected it in 1906. Preferred original forestsin the hills and mountains. Microscells siquijorensis monticola Bourns and Worcester. Mottled-breasted Bulbul.--Collected by: Bourns and Worcester, McGregor. Not found since McGregor collected it in 1906. Said to live in mountain forests. Its congener, M.p. philippinus, is still very commonin the hills and mountains,among second growth patchesand even in coconutgroves. Copsychuscebuensis Steere. Black Shama.--Collectedby: Steere Expedition, Bourns and Worcester,McGregor, and Empeso. Lives in original forests,dense thickets,and densesecond growth mixed with thickets. Its adaptation to second growth and thickets will help much in its survival on the island. F. Empeso collecteda singlespecimen, a male with the testesenlarged, on July 16, 1956, in dense secondgrowth mixed with thickets. Its congener,G. saularismindanensis, is a very commonbird in secondgrowth, bamboogroves, hedge growthsin cultivated areas,and even in gardens. Dicaeum trigonostigmapallidius Bourns and Worcester. Orange-breasted Flowerpecker.--Collectedby: Everett, Bournsand Worcester,McGregor. Not found since McGregorcollected it in 1906. Lived in original forestsin the lowlands, hills and mountains, especiallyclose to the edges, but also ranged in second growthand clearings. McGregor (1907,Phil. Journ. Sci.,II A, p. 307) basedon his observationsof the specieson Cebu in 1906,writes: "This speciesis the most commonmember of the family Dicaeidaein Cebu." [- Auk 40 RABOl•,Impact of Deforestationon Birdsof Cebu •_Vol.76

Dicaeum quadricolor Tweeddale. Four-Colored Flowerpecker.--Collectedby: Everett, Bourns and Worcester, McGregor. Not found since McGregor collected it in 1906. Lived in original forests in the lowlands and hills. Its congener, D. a. australe(papuense of authors), remainsvery abundantall over the island. Zosteropseveretti everetti Tweeddale. Everett'sWhite-eye.--Collected by: Everett, SteereExpedition, Bourns and Worcester,McGregor. Not found since McGregor collected it in 1906. Lived in lowland and hill forests and also ranged in second growth. Its congener,Z. everertl slqUi]orensls,on Siquijor Island, is still a fairly com- mon bird in second growth patches. Oriolus xanthonotusassimilis Tweeddale. Dark-throated Oriole.--Collectedby: Everett, Bourns and Worcester, McGregor. Not found since McGregor collected it in 190õ. Bourns and Worcester (in McGregor, 1909, A Manual of Philippine Birds, p. 701) write of this speciesthus: "0. assimilisis exceedinglycommon in the small amount of forest left in Cebu." This observation was made in 1892.

FOREST SPECIES Some forest speciesthat we found in the courseof our work on Cebu include the following: Ducula aenea aenea Linnaeus. Green Imperial Pigeon. Kakatoe haematuropygiaMtiller. Philippine Cockatoo. Prioniturus discurus whiteheadi Salomonsen. Blue-headed Racketstailed Parrot. ½uculusfugax pectoralis Cabinis and Heine. Horsfield's Hawk Cuckoo. Ceyx lepidus margarethae Blasius. Variable Forest Kingfisher. Pitta e. erythrogasterTemminck. Red-breasted Pitta. Pachycephalaplateni winchelli Bourns and Worcester. White-bellied Whistler. Parus elegans albescensMcGregor. Elegant Titmouse. Sitta frontalis aenochlamysSharpe. Velvet-fronted Nuthatch. However, seven other forest speciespreviously recorded were not found by us: Gallus gallus gallus Linnaeus. Red Jungle Fowl. Leucotreron occipitalis Gray. Yellow-breasted Fruit Dove. Leucotreronl. leclancheriBonaparte. Black-chinnedFruit Dove. Ducula p. poliocephala Gray. Pink-bellied Imperial Pigeon. Terpsiphonecinnamomea unirufa Salomonsen.Rufous Paradise Flycatcher. ½ulicicapahelianthea panayensis Sharpe. Citrine Canary Flycatcher. Chloropsisf. fiavipennis Tweeddale. Yellow-quilled Leafbird. It is possiblethat theseand the nine endemicshave disappeared from the island. However,there is also the possibilitythat some persistin secondgrowth we did not find. Many of the forestspecies that we found were in reforestedareas, and the soleendemic rediscovered was also in sucha place. Possibly someof the otherforest species that we did not find may actually persistin verysmall numbers in scatteredlocalities. If so,their only hope of survivalon the island is to colonizeand adapt to the re- forested areas. •9•9-• R•a•OR,Impact of Deforestation onBirds of Cebu 41

NEW BIRD RECORDS We found severalspecies previously unrecorded from Cebu: lxobrychussinensis astrologus Wetmore, Chinese Least Bittern.--Basak,Cebu City: 1 female adult, September5, 1956 (CNHM). Wing 130; culmen from frontal leathering 43.5 mm. The bird was taken at the side of a small irrigation ditch in rice fields, when the rice plants were maturing. This speciesis not as commonlyencountered as I. cinnamomeus,which is also found in the same type of haunts. The Chinese Least Bittern is more likely to be met with in Mangrove and Nipa swamps. Streptopelia chinensistigrina (Temminck and Knip), Tigrine Dove.--Tuburan, Cebu: 1 male adult, October4, 1956 (SU). Wing 144; culmenfrom base21 mm. The Tigrine Dove is gradually extending its range in the Philippines from Palawan and Balabac (its original range in the Philippines) to Zamboanga Peninsula,Mindanao Island (Rabor, 1952. Auk, 69(3), pp. 255-256) and Negros (Rabor, 1954,Silliman Journal, 1 (1), pp. 79-80), and now to Cebu. Although pigeonsand dovesare kept as cagebirds in many placesin the Philippines,I do not believethat the presentspread of the Tigrine Dove is by this means. I am moreinclined to ascribeits spreadto its s•ccessfulcrossing and consequent colonizationfrom one island to another, aided perhaps by the strong monsoon and typhoon winds. Cacomantisvariolosus sepulcralis (S. Milllet), Ruœous-breastedBrush Cuckoo.-- Tisa, Cebu City: 1 female immature,January 30, 1956 (CNHM); BuhisanDam, Cebu City: 1 male immature,July 23, 1956 (YPM); 1 female adult, October22, 1956 (CNHM); 1 female immature,September 7, 1956 (CNHM). Wing /5 114, $ 119, 118; culmen from base • 23.5, $ 23, 23.5 mm. The Rufous-breasted Brush Cuckoo has been confused with C. m. merulinus in the past so that recordsof the latter on variousislands, including Cebu, might really have included C. v. sepulcralis. The immature female in the ChicagoNatural History Museumcollection has just completedits molt to the adult plumage,and one secondaryand a few upper wing covertsare stiff of the juvenal plumage. The other immaturefemale specimenin the samemuseum has still retaineda few of the characteristicstriped juvenalfeathers on the throat and fore breast,otherwise the retainingpart of the plumage is that of the adult. The immaturemale in the PeabodyMuseum collection still possessessmall remnantpatches of the juvenal plumageboth on the upperpartsand underparts. The rectricesare molting to thoseof the adult. All the specimenswere taken in densetree growthswithin or closeto the reforestationproject in the hills backof the city, in the areassurrounding the water reservoir. Halcyon coromandabangsi Oberholser, Ruddy Kingfisher.--BuhisanDam, Cebu City: 1 female adult, December 12, 1955 (SU); 1 male adult, October 23, 1956 (CNHM). Wing • 118, $ 117;culmen from base• 58, $ 57.5mm. The Ruddy Kingfisherseems to be an uncommonwinter visitor in the Philippines,except on SiquijorIsland where 7 specimenswere collected within a comparativelyshort time, within two remnantpatches of well-loggedoriginal forest. Three race•have been identifiedin the Philippines:H. c. major, H. c. bangsl, F Auk 42 R^•o•, Impacto• Deforestationon •irds o! ½ebu LVol.?õ and H. c. minor. The first two are winter visitorsin the Philippinesbut the last one is a breedingresident form in the Sulu Archipelago. The two Cebuspecimens are similarto the birdscollected on Siquijorand Negros,which proved to be H. c. bangsi,after a comparativestudy of the various forms was made by Dr. Rand (Rand and Rabor, MS) in connectionwith a study of the avifauna of Siquijor Island. At presentH. c. bangsihas been recorded as a wintervisitor on Siquijor,Negros, and Cebu. Monticolasolitaria philippensis (P. L. S. Mtiller), Blue Rock Thrush.--This winter visitorhas not beencollected on Cebu as specimenbut I have seenit on severaloccasions, right in the city, on the stone walls and roofs of the old churches,even while I was a youngboy living in Cebu City. Again, in March, 1954and April, 1955,I saw the speciesin the vicinity of the sameold stone churches. Gerygonesulphurea sulphurea Wallace, Yellow-breasted Wren-warbler.--Paena-an, Mandawe,Cebu: 1 male adult, January31, 1954 (CNHM); Kanghabagat,Medellin, Cebu: 1 male adult, 2 female adults,July 19-21, 1954 (CNHM). Wing • 50, 51.5, 51, 51.5; culmen from base • 12.5, 12.5, 9 12.5, 12.5 min. The Yellow-breastedWren-warbler, strangely enough was not collectedby the earlier collectorson Cebu in spite of its being now relativelycommon on the island,especially in the Mangroveforest or remnantpatches of it. Its songis very melodious,loud and clear and cannot be mistaken for that of any other species. The Cebu birds do not differ from Negros and Bohol birds. Megaluruspalustris forbesi Bangs, Striated Canegrass Warbler.--Lico-lico, Cebu: I maleadult, January12, 1954 (CNHM); Canyasan,Cebu: 1 male adult, September 26, 1956 (CNHM). Wing /• 97.5, I01; culmenfrom base /• 23, 24 min. The Striated CanegrassWarbler is another speciesthat is fairly common on Cebu, especiallyin the rice fields in the narrow coastalplain, and in the tall grass areas in the foothills. However, the bird is more often heard than seen, becauseof its habit of feeding on the ground among the dense tall grass and similar dense growths. A favorite haunt of the bird is the dry rice fields after the harvest, where it feeds on the ground close to grazing carabaos and cattle. When disturbed it usually flies to the nearest tree, often Nauclea orientalis (Bangkal) or Ceiba pentandra (Doldol or Kapok), which trees are often planted as hedgesaround the rice fields. From the safetyof a high bare branchclose to or at the top of the tree, the bird givesits very characteristiccall, a seriesof loud rolling, warbling notes, rather musical to hear. The Cebu specimensdo not differ from Negrosand Bohol birds. Muscicapanarcissina narcissina (Temminck), NarcissusFlycatcher.--Campo 3, Buhisan Dam, Cebu City: 2 male immature, November 3, 5, 1956 (CNHM). Wing /• 75, 77; culmen from base /• 13.5 14 min. The NarcissusFlycatcher is a rare winter visitor in the Philippines. It has been recorded so far only on Calayan, Luzon, Mindanao, and Negros. The presentrecord on Cebu extendsits winter range by one more island in the Philippines. Muscicapagriseisticta (Swinhoe), Gray-spotted Flycatcher.--Tisa, Cebu City: 1 femaleadult, January28, 1954 (CNHM); Bacsan,Cebu: 1 sex ?, December10, 1954 (SU); Samboan,Cebu: 1 male adult, January27, 1955 (SU). Wing /• 84, 9 84.5,sex ? 81.5;culmen from base /• 14, 9 12.5,sex ? 13. min. t959-J RABOR,Impact of Deforestationon Birdsof Cebu 4B

The Gray-spottedFlycatcher is widely distributedin the Philippinesas a winter visitor, but is never found in large numbers in any one area. It is strange that it was not recorded on Cebu by the earlier collectors,considering the fact that it frequentseven cultivated areas provided there are some tree growths around them. Padda oryzivora (Linnaeus), Java Sparrow.--TheJava Sparrowhas alwaysbeen a popular cagebird in Cebu and still is. Even today, severalChinese pet stores in the city always have cagesjust for these sparrows,oftentimes containing both the normally-coloredand the albino birds. It is evident that the source of the birds that have by this time already succeededin establishinga breeding popula- tion in the hills of Cebu, has been cage escapes. In 1922-26, as a small boy who roamed the hills of Cebu City in companywith other small boys,all armed with sling shots and later, with air rifles, the Java Sparrow always attracted us whenever one was seen or a small flock observed. It was not uncommon for one or two of these birds to join the flock of the Chestnut Mannikin, Lonchura malaccajagori, and feed with the members. Occasionally,a flockof Java Sparrow numbering about from 6 to one dozen, was encountered,sometimes with a member or two which were albino. Somehowthe specieshas never increasedin large numbers,perhaps because of the overhuntingby small boys, even up to the present. AGKNOWLEDGMENTS

I am greatly indebted to the John Simon GuggenheimMemorial Foundation, Chicago Natural History Museum, Yale University, and the United Board for Christian Higher Education in Asia, for the fellowship and travel grants that have enabled me to come to the United States and pursue the studies on Philippine birds and prepare reports on them for publication,under the advice of or in collaborationwith Dr. A. L. Rand, Chief Curator of Zoologyof the ChicagoNatural History Museum,and Dr. S. Dillon Ripley, Curator of Vertebrate Zoologyof the Yale University Peabody Museum.

SUMMARY Cebu Island,Philippines, was largely deforested by the early twen- tieth centuryand newforests, later developedby the government,were destroyedduring the SecondWorld War. A recent surveyoœ its bird life indicatesthat all but one of its endemicforms, as well as severalother forestspecies, may have dis- appeared. Ten forms (six resident) not previouslyrecorded from Cebu were found.

$illimanUniversity, Dumaguete City, Negros Oriental, Philippines.