Feb 7, 2011

Vanishing Treasures of the Philippine Rain Forest

by Angel C. Alcala

It was a great experience for me to conduct field work from the 1950s through the 1970s in tropical rain forest in its pristine state on the Philippine islands of Bohol, Mindanao, Mindoro, Negros and Palawan. At that time, the old growth lowland rain forest still existed at sea level; large trees with huge buttresses and straight boles towered to 30m or more to form the tallest story. The crowns of the lower tree strata formed a continuous forest canopy, effectively preventing light rays from penetrating to the forest floor, except in areas where the canopy was broken by fallen trees. Climbing bamboos, rattan, tree ferns, palms, and lianas were abundant. Many ferns, aerial mosses, and orchids grew on tree trunks. The forest floor was often covered with decaying vegetation and leaf litter, harboring a rich assemblage of small animals and lower plants. 

Beginning at about 1,000 meters, we saw montane forest trees that were shorter and heavily encrusted with mosses. This forest abounded in aerial ferns and screw pines, the latter growing so thick that they impeded human movement. The montane rain forest was always wet because of year-round rainfall, storing enormous volumes of water, and humidity was always high, from 70-100%, even during dry periods. The complex forest structure provided for a large number and variety of animal microhabitats.

The relative quiet in the forest during the day was frequently broken by animal calls and sounds of animal movements and the occasional breaking of twigs and branches. It was a different story at night, when we heard a symphony of sounds made by birds, frogs and insects.

In the Philippines, biodiversity and natural history are tightly interlinked with geological history. Once difficult to explain, the presence of a host of unique and endemic plant and animal species is rendered somewhat easier to understand today by the advances in our knowledge of land connections, movements and break-up of continents, formation of oceanic islands through tectonic events, and evolutionary processes leading to specialized niches of organisms in the tropics where temperatures show almost no variation throughout the year. There is great diversity in the geological history Among the Philippine islands. Luzon and Mindanao, for example, have large areas that are more than 25 million years old, while the others are generally of more recent age, from 10 million to no more than 100,000 years. Most islands are oceanic in origin, but Palawan, Mindoro and Panay have an Asiatic continental component. More recently, the development of glaciers in polar regions about 20,000 years ago and 160,000 years ago, which lowered the sea level by 120m or more, would have created five major islands - namely Greater Sulu, Greater Palawan, Greater Negros-Panay, Greater Mindanao and Greater Luzon -- and joined Palawan with Borneo, but it would not have closed the gaps between Borneo and Greater Sulu and Greater Mindanao, or Greater Mindanao and Greater Luzon. In geologic and biogeographic terms, Palawan is not part of the Philippines but of the Greater Sunda Islands (Borneo, Java and Sumatra), which were at times dry-land extensions of the Indochina-Malay region.

This diverse geological history provides an ideal opportunity to study evolution in action. Aside from evolutionary mechanisms promoting speciation in the rain forests, the partitioning of the Philippines into islands separated by sea barriers has contributed to the formation of endemic species (those that are unique to some specific area) through geographic isolation, thus preventing interbreeding. On large islands, populations have been isolated on mountain peaks separated by swaths of lowlands that also prevented gene flow. Resolving the details of many issues concerning biodiversity in the Philippines remains a great challenge, and will require further field and laboratory studies. Much remains to be learned.

The number of plant and animal species in the Philippine rain forest is incompletely known. There are an estimated 13,500 plant species, of which about 8,000 are flowering plants; about 3,200 are endemic. Philippine land vertebrate species number about a thousand: approximately 80 amphibians, some 240 reptiles, 556 birds (resident and migratory), and 174 mammals. These numbers will certainly be revised upwards as new species are still being discovered. In fact, we have described eight new species of forest frogs in a space of five years and Dr. Lawrence Heaney and his colleagues have reported 16 new mammal species during the last ten years. It is the exceptionally high level of endemism that is now attracting international attention. Seventy-five percent of the amphibians, 70 percent of reptiles, 44 percent of birds, and 64 percent of mammals are found nowhere else in the world. Dr. Heaney believes that Philippine mammals have the highest percentage of species endemism in the world on a hectare-for-hectare basis, and this could be true for other groups as well.

The Tropical Rain Forest has supplied indigenous Philippine peoples with a treasure trove, including lumber, food, drinks, spices and medicine. It is to the credit of these indigenous human communities that they have used forest resources in a sustainable way. But it is a sad fact that today only remnants of this forest can be found, mostly in less accessible parts of the Philippines, especially in mountainous areas. In 1934, the total forested area was estimated at 17 million hectares, or 57% of the country s total land area of 30 million hectares. But in 1993, the area was reduced to 5.7 million hectares, or 19% of the land area, and most was secondary forest. The primary or original tropical lowland forest was only 872,000 hectares, the logged-over lowland forest about three million hectares, and the montane forest about a million hectares. Thus, only about 1.87 million hectares, about 6 percent, have remained as prime habitats of wildlife. The immediate reasons for the drastic reduction of the primary forest area are large-scale logging and conversion to agriculture, and arestrongly associated with the rapid increase in human population, reaching about 70 million in 1997. Over 15 million upland people today threaten the survival of the remaining forests, despite government effort at protection.

A large number of endemic species in the Philippine tropical rain forest and the forest itself are now threatened with complete destruction, making the country a “hot spot”, that is, an area where there is a high probability of species extinctions. Already some 52 native vertebrate species are in the critical or endangered categories, and a great many more are listed as threatened. The frog Platymantis spelaeus and the fruit bat Dobsonia rabori are almost surely extinct, and another frog, a bushy-tailed cloud rat, and at least one species of bird are probably extinct as well. Most endemic land vertebrates (including birds, small arboreal frogs, and many mammals) require primary-forest habitats and fail to survive in highly disturbed and secondary forests. Preservation of the primary rain forest is therefore a high priority for the Filipino people.

This book, which is published in connection with the Field Museum exhibits to commemorate the Philippine Centennial in 1998, is indeed a significant contribution. The authors have described the vanishing treasures of our Philippine tropical rain forest in both words and images. Both authors, being scientists with long research experience in the Philippines, are eminently competent to present the case for these treasures to the readers. Drs. Heaney and Regalado deserve our commendation for writing this book with a broad audience in mind and for reminding us how much humankind will lose if the Philippine tropical rain forest is not preserved. It is my hope that through this book, readers will better understand and appreciate the role of the Philippine tropical rain forest, its biodiversity, and their impact on human affairs and that, as a result, they will contribute resources to the preservation of this forest, which still holds many secrets for us and future generations to unravel.

Commission on Higher Education
Republic of the Philippines

I. Introduction
By Lawrence R. Heaney

Arrival on Mount Isarog

Its whiskers quivering and sweeping back and forth, the little animal was one of the oddest creatures I had ever seen. With long, narrow hind feet, hefty haunches, and small but stout forelimbs and claws, it looked a bit like a tiny kangaroo. But the small size, silvery fur, and long, delicately tapering snout tipped with tiny teeth marked it as something utterly unlike a kangaroo, or anything else. Danny, one of the young subsistence farmers we had hired to help us with trapping and camp work, had just brought it into camp, the broad grin on his face instantly showing that he thought he had a prize for us. He was unquestionably right.

II. Discovering Diversity
By Lawrence R. Heaney

A celebration of an endangered habitat

When a typhoon hits Mount Isarog directly, up to a meter of rain can fall in a day, but the high mountain forests of Mount Isarog function as a gigantic sponge, soaking up the heavy rains and releasing the water slowly into the groundwater system. This natural water-control system prevents floods, but it also prevents droughts by gradually releasing water throughout the year into springs, streams, and rivers, even during the two-to-four-month dry season that occurs in the lowlands each year. The Isarog shrew-rat, the earthwormsit eats, and the habitat in which they live all form part of the network of mountain rain forests that supplies one of the most critical needs of the human societies that also live in the area—clean, steadily-flowing water.

On breezy days during our field studies on Mount Isarog in 1988, we could hear only the sounds of neighboring birds and frogs, as the sighing of the wind in the trees covered other sounds from farther away. On days when the wind was still, from dawn to dusk we were serenaded by a different sound—the roar of chain saws and the crashing of trees echoing to us from lower on the slopes. We heard a dozen or more big trees being felled and cut each day, rumbling like thunder in the distance. When we visited the sites where the cut trees lay, we found young subsistence farmers, who had rented a chain saw from a local businessman with the promise to deliver timber to the nearest road, where a truck would pick up the wood. The truck would climb the mountain into the national park every few weeks, pick up lumber from enough locations to make a full load, then haul it to Naga City under the cover of darkness. We were told that at the check-points set up by government agencies and police, payments were made to assure that everyone received a share from the illegal logging, and the next day beautiful hardwood lumber was available at the hardware store owned by a relative of a prominent local politician. After paying for the loan of the chain saws, the subsistence farmers who did the difficult and dangerous work of cutting the trees received the equivalent of a few dollars per day, and those receiving payoffs, who did nothing but look the other way, received enough to extend their meager salaries. Most of the proceeds from the logging went to the family of the businessman and politician. Of course, none of the proceeds went for park management or reforestation.

III. The Origins and Dimensions of Biodiversity in the Philippines
By Lawrence R. Heaney

Ancient Geological History of the Philippines

Recent evidence, primarily from exploration for oil deposits, shows that the main landmass of the Philippines originated more than 50 million years ago as a series of "island arcs" far out in the Pacific Ocean. As the rocks beneath the sea were gradually squeezed between the Asian continent and the northward-moving Australian continent, which was then much farther south than it is today, parts of the sea-floor were uplifted, and others were thrust beneath the crust of the earth. The pressure and friction generated by this plate-tectonic movement produced undersea volcanoes that gradually rose above the waves. By about 30 million years ago some small but permanent islands protruded above sea level, and by 25 million years ago, several islands of at least 1,000 square kilometers had been established.

Australia continued to move northward and westward, with the pressure on the region between it and Asia forcing the precursors to the Philippine Islands to move toward Asia, resulting in still more volcanic activity. By 15 million years ago, this led to the creation of a large island of 25,000 to 50,000 square kilometers, with extensive highlands that included parts of what is presently northern Luzon. The modern southern Philippines still lay far to the south at this point, and included only a few, much smaller islands.

Southeast Asia assumed much of its current shape only about five million years ago. By this time, the modern highlands of northern Luzon were well-established. Another island reached from southern Luzon nearly to Mindanao, and Mindanao itself consisted of several separate islands that progressively merged. Small islands continued to appear throughout the archipelago, including the Sulu Islands. Palawan and Mindoro, the only parts of the Philippines that had originated as pieces of the Asian mainland, became isolated at this time as well, with Mindoro probably dropping entirely below sea level for a time.  

Although many of the details in this story remain unclear, the broad picture has become evident for the first time. We now believe that the ancient geological history of the Philippines is largely responsible for its exceptional array of biological diversity. Because the islands arose many millions of years ago, independently of the Asian mainland, with the exception of Palawan and Mindoro, they have had adequate time and space to receive and shelter rare, over-water animal and plant pioneers. But why, in comparison to nearby countries with similar climates, are levels of diversity so high in the Philippines? And why do such small islands as Sibuyan have such extraordinary numbers of unique species, while some other islands of the same size in the Philippines have none? To answer these questions, we must turn to the more recent geological history of the archipelago.

IV. Vanishing Treasures
by Jacinto C. Regaldo, Jr. and Lawrence R. Heaney

In this section, you can learn about specific plants and animals of the Philippine Islands. Proceed to http://www.fieldmuseum.org/vanishing_treasures/Vanishing_1.htm

V. The Causes and Effects of Deforestation
by Lawrence R. Heaney

When the first humans arrived in the Philippines from adjacent Asia many thousands of years ago, they found an archipelago that was remarkably rich in natural resources. The seas were inhabited by the earth's most diverse marine communities on earth, providing an abundant source of food throughout the year. The land was covered almost entirely by rain forest that provided them with meat from wildlife, building materials, and seemingly everlasting supplies of clear, cool water.

Those natural resources have been squandered, so badly damaged by over-use, mismanagement, and greed that recovery is uncertain, and collapse seems to be a real possibility. The nation now faces stark alternatives: a decline from the biologically richest place on earth to environmental devastation, or recovery from the current brush with disaster to a point of stability. To understand the origin of this dramatic and terrible situation, we must begin with history, but must end with societal and personal choice.

The Lost Forest

Few countries in the world were originally more thoroughly covered by rain forest than the Philippines. Brazil has extensive Savannah and brush; Indonesia has many dry islands; Kenya and Tanzania have only small patches of rain forest. A few hundred years ago, at least 95 percent of the Philippines was covered by rain forest; only a few patches of open woodland and seasonal forest, mostly on Luzon, broke the expanse of moist, verdant land.

By the time the Spanish arrived in the Philippines in the 16th century, scattered coastal areas had been cleared for agriculture and villages. The only domestic grazer was the water buffalo, and pastureland was very limited. Some forest had been cleared in the interior as well—particularly the terraced rice lands of the Central Cordillera of northern Luzon—but most coastal areas and the richest of the lowlands remained completely forested, broken only by the occasional cultivated clearings. By 1600, the human population of the Philippines probably numbered about 500,000, and old-growth rain forest over 90 percent of the land, home to thousands of plant and animal species interacting in the web of life that sustained the human population.

At the end of more than 300 years of Spanish colonial rule, rain forest still covered about 70 percent of the Philippines. Some islands had been heavily deforested, while others remained nearly untouched. Cebu was so badly deforested that ornithologists visiting the island in the 1890s reported that they could find no old-growth forest, and the neighboring islands of Bohol and Panay had less than half of their original forest. Although the fertile lowland plains of Luzon had largely been cleared, much of the highland rain forest remained intact. Mindoro's rain forest was protected by an especially virulent strain of malaria, Palawan's by its isolation, and Mindanao's was largely left untouched because of the aggressive independence of the Moro people. The plant and animal communities retained their integrity, readily able to provide resources to human populations in all but a few places.

In 1992, the date of the most recent forest survey, old-growth rain forest had declined to a shocking 8.6 percent. In late 1997 that percentage has probably dropped to seven percent, and perhaps further still. The extent of rain-forest destruction in the Philippines may represent another "first": In addition to probably having the highest density of both unique and endangered species in the world, its decline in old-growth forest from 70 percent to seven percent in less than a century is probably the most rapid and severe in the world. This destruction is a primary reason the Philippines is ranked as having the most severely endangered mammal and bird faunas in the world. The degradation is also responsible for the increasing floods and droughts in the country, as well as massive erosion, coral reef siltation, and groundwater depletion.

VI. Prospects for Recovery
By Lawrence R. Heaney

The Case for Hope

Plotting a corrective course for a country with such severe social and environmental problems as the Philippines is an enormous challenge. The damage has been enormous, and the extent of change required to turn the system from one of approaching disaster to one of long-term stability is daunting. However, many aspects of the decline that began long ago have been reversed or at least slowed.

One of the greatest problems for decades was a paucity of accurate and current information on wildlife, forests, and the environment in the Philippines. This is changing rapidly; newspapers now avidly cover stories about floods, droughts, and deforestation, and highlight corrupt practices that come to light. Information is gradually making its way into grade school and high school curricula, and books about nature and wild animals and plants are being published increasingly frequently; for example, the Philippines now has the best field guide to marine mammals of any country in Southeast Asia, and the new Philippine Red Data Book is one of the first comprehensive listings of endangered species for a developing country.

When I began doing field work in the Philippines in 1981, there were perhaps a half-dozen active Filipino researchers studying wild mammals, birds, reptiles, and amphibians; at the time, there was virtually no funding to support research, and speaking or writing about environmental issues of any sort was likely to result in harassment and intimidation, loss of employment, and occasionally worse. In 1991, with funding from the MacArthur Foundation through The Field Museum, a program of training and field research was established for young field biologists, and the Wildlife Conservation Society of the Philippines was founded. The level of interest in wildlife research has grown dramatically; attendance has gone from about 25 at the first meeting to over 175 at most recent meetings, many of the participants enthusiastic graduate students who are doing excellent field studies. The members of the society work together to conduct research, promote knowledge and training, and act as the primary conduits for getting new information about biodiversity to the public.

For some of the most severely endangered species, integrated programs of field studies and captive breeding of conspicuous flagship species have been established. Although captive breeding will never provide the stability that comes with successful protection of the natural habitat, such programs provide personal contact with endangered native species to thousands of Filipinos every year, raise consciousness about environmental problems, and keep alive the possibility of reintroducing endangered species into former habitat once conditions in the countryside improve. One of the most successful involves the Visayan spotted deer; although wild populations continue to dwindle, the captive herd is now well over 100 individuals and growing rapidly. With gradual improvement in conditions on the mountains of Negros, the prospect of release of some captive animals into the beautiful area around Lake Balinsasayao seems to be approaching rapidly. Captive breeding programs for the giant fruit bats, endangered wild pigs, and some other species are also contributing to conservation in various parts of the country. Unfortunately, the older and larger projects—especially those for the tamaraw and the Philippine eagle—remain mired in controversy and have yet to produce a positive result. In all cases, a clear emphasis on protection of wild populations ought to be the top priority, especially since these large species provide one of the best sources of public support for protection of the rain forest.
One of the most positive signs in recent years has been the rejuvenation of the system of national parks and other protected areas. During the Marcos years, none of the parks received meaningful protection, and many of the parks were partially logged by companies holding permits for logging on their boundaries; several parks were almost entirely clear-cut. Several internationally funded projects are now under way, after assessment studies that began in 1989. Beginning in 1994, the Global Environmental Facility of the World Bank provided funding for management, protection, and community development at ten sites, and in 1996 the European Union provided funding for eight additional sites (some are marine, but most are rain forest). Additional funding for similar projects has come from the Danish and Dutch governments. Equally importantly, the Philippine government has moved actively to declare new national parks and protected areas in critical regions in the last several years, including Mount Kitanglad in northern Mindanao, the mountainous cores of Sibuyan and Camiguin islands, and the Northern Sierra Madre Wilderness Park in northeastern Luzon, now the largest national park in the country. Although new parks and greatly improved protection activities are badly needed, there has been remarkable progress. One especially positive aspect of the new national park system is that it is gradually being shaped to provide protected areas in every biogeographical region in the country. The Philippines may soon be one of the first countries in the world to have a park system that is specifically designed to protect biological diversity. The primary challenges for the park system at this time are to increase coverage of the lowland dipterocarp forest, which has been most severely decimated in recent decades (both outside and inside the parks), to find constructive, effective ways of drawing poor farmers out of the parks, and to bring an end to the illegal logging that continues to go on in most of the parks.

VII. Bibliography and Credits

The On-line edition of: Vanishing Treasures of the Philippine Rainforest was made possible by generous support from the Field Museum of Natural History Scholarship Committee.
Site Development: Anne Firlit, Lawrence Heaney, and Sean O. Bober
Site Design: Anne Firlit


Although this book was written by two people, it is the product of many years of work by many people; to all, we wish to express our heartfelt thanks. For assistance with field investigations, often under challenging conditions, we thank all of the hundreds of people who have kindly helped us to reach our study sites and live in the forest. We have been fortunate to be part of a group of wonderful collaborators on the research that lies behind this book; Nonito Antoque, Danny Balete, Boying Fernandez, Pedro Gonzales, Steve Goodman, Paul Heideman, Nina Ingle, Eric Rickart, Blas Tabaranza, and Ruth Utzurrum made especially great contributions to field work, and to many aspects of subsequent studies as well. Angel C. Alcala and the staff and students at Silliman University provided crucial assistance to Heaney in the early stages of his studies. Members of the Wildlife Conservation Society of the Philippines all deserve thanks for their enthusiastic support of our work. The Protected Areas and Wildlife Bureau of the Philippine Department of Environment and Natural Resources have provided permits, information, and support for our studies; we especially thank Wilfrido Pollisco, Corazon Catibog-Sinha, Samuel Penafiel, Alma Ballesfin, Jean Caleda, Carlo Custodio, Josie DeLeon, and Marlynn Mendoza at the DENR, and Pete Gonzales at the Philippine National Museum. Danny Balete, Rafe Brown, Paul Heideman, Christie Henry, Eric Rickart, and Benito Tan reviewed the manuscript; their comments and suggestions greatly enhanced the quality of the final product. We thank Rafe Brown, Keith Erickson, Tom Gnoske, Paul Heideman, William Oliver, Neil Rettig, Eric Rickart, Doel Soejarto, Benito Tan, Art Vogel, and Dave Willard for heroic efforts to provide photographs on a tight schedule, and Clara Simpson for the wonderful maps, charts, and graphs. Howie Severino, Danny Balete, and Jodi Sedlock helped with text and illustrations. Production of the book would not have been possible without the remarkable efforts of Ron Dorfman, Sarah Guernsey, Sophia Shaw, and Joan Sommers. To all of those named, and the many others whom we have not listed individually but have given us assistance and friendship, we express our deepest gratitude.

The Ellen Thorne Smith and Marshall Field Funds of the Field Museum, the National Science Foundation, the National Cancer Institute, and the John D. and Catherine C. MacArthur Foundation provided funding for most aspects of the field studies.

Dori Soler first urged us to write this book, and we thank her for her persistence. Christie Henry provided important encouragement. We would also like to acknowledge the Field Museum officials who paved the way for the project, including Peter Crane, Laura Gates, Melissa Hilton, John McCarter, and Willard E. White.

All skull photographs by Rebecca Banasiak. Photo restoration by Anne Firlit and Rebecca Banasiak. Photographs by: Frank Almeda, Rafe Brown, Richard Z. Chesnoff, Marian Dagosto, Keith Erickson, F.R.E.E. Ltd., Tom Gnoske and David Willard, Lawrence Heaney, Paul Heideman, J.S.H. Klompen, Liaison International, Peggy McNamara, Martin R. Motes, William L. R. Oliver, Jacinto C. Regalado, Eric Rickart, Sonny Sales, Larry Secrist, Clara Simpson, Doel Soejarto, Blas R Tabaranza, Jr., Benito C. Tan, Art Vogel, and John Weinstein.


Peggy McNamara, William L. R. Oliver, Jodi Sedlock, and Clara Simpson.

Maps and Charts:

All Philippine Maps were redrawn by Anne Firlit from 1998 illustrations by Clara Simpson and were based on Heaney 1986, 1991.

Alcala, A. C. 1976. Philippine Land Vertebrates. New Day Publishers,
     Quezon City. 176 pp.
Alcala, A. C. 1986. Guide to the Philippine flora and fauna. Vol 10,
     Amphibians and Reptiles. Natural Resources Management Centre
     and University of the Philippines, Manila.
Alcala, A. C. and C. C. Custodio. 1997. Status of endemic Philippine
     amphibians. Sylvatrop (1995), 5:72-86.
Asis, C. V. 1971. Plants of the Philippines. Science Education Center,
     University of the Philippines, Quezon City. 512 pp.
Baille, J., and B. Groombridge, 1996. 1996 IUCN Red List of Threatened
     Animals. International Union for the Conservation of Nature, Gland, 368 pp.
Balete, D. S., H. C. Miranda, L. R. Heaney, and J. F. Rieger. 1992.
     Diversity and conservation of Philippine land vertebrates: an annotated
     bibliography. Silliman Journal 36:129-149.
Balete, D. S., and L. R. Heaney. 1998. Density, biomass, and movement
     estimates for murid rodents in mossy forest on Mount Isarog,
     southern Luzon, Philippines. Ecotropica 3:91-100.
Bibby, C. J., N. J. Collar, M. J. Crosby, M. F. Heath, C. Imboden,
     T. H. Johnson, A. J. Long, A. J. Statterfield,and S. J. Thirgood. 1992.
     Putting Biodiversity on the Map: Priority areas for global conservation.
     International Council for Bird Preservation, Cambridge. 90 pp.
Braatz, S. 1992. Conserving Biological Diversity, A Strategy for Protected
     Areas in the Asia-Pacific Region. World Bank Technical Paper
     Number 193:1-66.
Broad, R. and J. Cavanagh. 1993. Plundering Paradise; The Struggle
     for the Environment in the Philippines. University of California
     Press, Berkeley. 197 pp.
Brown, W. C. 1997. Biogeography of amphibians in the islands of the
     Southwest Pacific. Proceedings of the California Academy of
     Sciences 50:21-38.
Brown, W. C. and A. C. Alcala. 1978. Philippine lizards of the Family
     Gekkonidae. Silliman University, Dumaguete City. 146 pp.
Brown, W. C. and A. C. Alcala. 1980. Philippine lizards of the Family
     Scincidae. Silliman University, Dumaguete City. 264 pp.
Brown, W. C. and A. C. Alcala. 1994. Philippine frogs of the family
     Rhacophoridae. Proceedings of the California Academy of
     Sciences 48:185-220.
Brown, W. C. and E. L. Alcala. 1995. A new species of Brachymeles
     (Reptilia: Scincidae) from Catanduanes Island, Philippines.
     Proceedings of the Biological Society of Washington 108:392-394.
Brown, W. H. 1919. Vegetation of Philippine mountains. Monograph of the
     Bureau of Science, Manila, 13: 1-434.
Christensen, T. D. and T. Lund. 1993. A comparison of the avian communities
     in different forest types in the northern Sierra Madre Mountains, the
     Philippines. Unpubl. M.Sc. Thesis, Zoological Museum, University of
     Copenhagen, Denmark. Vols. 1, 2, 63 + 72 pp.
Collar, N. J., M. J. Crosby, and A. J. Stattersfield. 1994. Birds to Watch 2.
     Birdlife Conservation Series 4: 407. Birdlife International, Cambridge.
Curio, E. 1993. Report on bird species recorded during a (preliminary)
     Philippines Conservation Expedition, 3 July - 26 August 1993. Unpubl.
     Report, Bochum, 32 pp.
Custodio, C. C., M. V. Lepiten, and L. R. Heaney. 1996. Bubalus
     mindorensis. Mammalian Species 520:1-5.
Danielsen, F., D. S. Balete, T. D. Christensen, M. Heegaard, O. F.
     Jakobsen, A. Jensen, T. Lund, and M. K. Poulsen. 1994. Conservation of
     Biological Diversity in the Sierra Madre Mountains of Isabela and southern
     Cagayan Province, the Philippines. BirdLife International, Manila and
     Copenhagen, 146 pp.
Delacour, J., and E. Mayr. 1946. Birds of the Philippines. MacMillan
     Co., New York. 309 pp. Developmental Alternatives, Inc. 1992.
     An Aerial Reconnaissance of Closed Canopy Forests. Natural
     Resources Management Program, Manila. 71 pp.
Dickinson, E. C., R. S. Kennedy, and K. C. Parkes. 1991. The birds
     of the Philippines, an Annotated Checklist. British Ornithologists’
     Union, Tring. 507 pp.
DuPont, J. E. 1971. Philippine birds. Delaware Museum of Natural
     History, Greenville. 480 pp.
Evans, T. D., G. C. L. Dutson, and T. M. Brooks. Cambridge Philippines
     Rainforest Project 1991, Final Report. Birdlife International, Cambridge.
     96 pp.
Fairbanks, R. G. 1989. A 17,000-year glacio-eustatic sea level record:
     influence of glacial melting on the Younger Dryas event and deep-sea
     circulation. Nature 342: 637-642.
Ferner, J. W., R. M. Brown, and A. E. Greer. 1997. A new genus and
     species of moist closed canopy forest skinks from the Philippines.
     Journal of Herpetology 31:187-192.
Fooden, J. 1991. Systematic review of Philippine macaques (Primates,
     Cercopithecidae: Macaca fascicularis subspp.). Fieldiana: Zoology,
     new series 64: 1-44.
Fooden, J. 1995. Systematic review of Southeast Asian longtail macaques,
     Macaca fascicularis (Raffles, [1821]). Fieldiana: Zoology, new series
     81: 1-206.
Fuller, M., R. McCabe, I. S. Williams, J. Almaco, R. Y. Encina, A. S.
     Zanoria, and J. A. Wolfe. 1983. Paleomagnetism of Luzon, pp. 79-84.
     In Hayes, D. E., ed., The Tectonic and Geologic Evolution of South-
     east Asian Seas and Islands: Part 2. American Geophysical Union
     Monograph, 27: 1- 396.
Gamalinda, E., and S. Coronel (eds.). 1993. Saving the Earth: The Philippine
     Experience(Third Ed.). Philippine Center for Investigative Journalism,
     Makati. 203 pp.
Gonzales, P. C. 1983. Birds of Catanduanes. Zoological Papers National
     Museum Manila 2:1-125.
Gonzales, P. C., and C. P. Rees. 1988. Birds of the Philippines. Haribon
     Foundation for the Conservation of Natural Resources, Manila. 184 pp.
Goodman, S. M. and P. C. Gonzales. 1990. The birds of Mt. Isarog National
     Park, southern Luzon, Philippines, with particular reference to altitudinal
     distribution. Fieldiana Zoology, new series 60:1-39.
Goodman, S. M. and N. R. Ingle. 1993. Sibuyan Island in the Philippines:
     threatened and in need of conservation. Oryx 27:174-180.
Goodman, S. M., D. E. Willard, and P. C. Gonzales. 1995. The birds of
     Sibuyan Island, Romblon Province, Philippines, with particular reference
     to elevational distribution and biogeographic affinities. Fieldiana Zoology,
     new series 82:1-57.
Groombridge, B. (ed.). 1992. Global Biodiversity: Status of the Earth’s Living
     Resources. Chapman and Hall, London. 585 pp.
Guzman, E. de, R, M. Umali, and E. D. Sotalbo. 1986. Philippine Dipterocarps.
     In Guide to Philippine Flora and Fauna III:1-74.
Guzman, E. de, E. S. Fernando. 1986. Philippine palms. In Guide to Philippine
     Flora and Fauna IV:147-254.
Hall, R. 1996. Reconstructing Cenozoic SE Asia, pp. 153-184. In Hall, R., and
     D. Blundell eds., Tectonic Evolution of Southeast Asia. Geological Society
     Special Publications 106:1- 566.
Hamilton, W. 1979. Tectonics of the Indonesian region. Geological Survey
     Professional Papers, 1078: 1-345.
Harper, P. and E. S. Peplow. 1991. Philippines Handbook. Moon Publications
     Inc., Chico.587 pp.
Hashimoto, W. 1981. Geological development of the Philippines, pp. 83-170,
     and supplementary notes on the geological history of the Philippines,
     pp. 171-192. In Kobiyashi, T., R. Toriyama, & W. Hashimoto, eds.,
     Geology and Palaeontology of Southeast Asia 22: 1-192.
Heaney, L. R. 1986. Biogeography of mammals in Southeast Asia: estimates
     of rates of colonization, extinction, and speciation. Biological Journal of
     the Linnean Society 28:127-165.
Heaney, L. R. 1991. An analysis of patterns of distribution and species
     richness among Philippine fruit bats (Pteropodidae). Bulletin of the
     American Museum of Natural History 206: 1-432.
Heaney, L. R., D. S. Balete, L. Dolar, A. C. Alcala, A. Dans, P. C. Gonzales,
     N. Ingle, M. Lepiten, W. Oliver, P. S. Ong, E. A. Rickart, B. R. Tabaranza,
     Jr., and R. C. B. Utzurrum. 1998. A synopsis of the mammalian fauna of
     the Philippine Islands. Fieldiana Zoology new series 88:1-61.
Heaney, L. R., D. S. Balete, E. A. Rickart, R. C. B. Utzurrum, and P. C.
     Gonzales. 1999. Mammalian diversity on Mt. Isarog, a threatened
     center of endemism on southern Luzon Island, Philippines. Fieldiana
     Zoology new series 95:1-62.
Heaney, L. R., and P. D. Heideman. 1987. Philippine fruit bats, endangered
     and extinct. Bats 5:3-5.
Heaney, L. R., P. D. Heideman, E. A. Rickart, R. B. Utzurrum, & J. S. H.
     Klompen. 1989. Elevation-al zonation of mammals in the central Philippines.
     Journal of Tropical Ecology 5: 259-280.
Heaney, L. R., and E. A. Rickart. 1990. Correlations of clades and clines:
     geographic, elevational, and phylogenetic distribution patterns among
     Philippine mammals. pp. 321-332. In G. Peters and R. Hutterer (eds.),
     Vertebrates in the Tropics. Museum Alexander Koenig, Bonn. 424 pp.
Heaney, L. R., and B. R. Tabaranza, Jr. 1997. A preliminary report on
     mammalian diversity and conservation status of Camiguin Island,
     Philippines. Sylvatrop (1995) 5:57-64.
Heaney, L. R. 1991. A synopsis of climatic and vegetational change in
     Southeast Asia. Climatic Change 19:53-61.
Heaney, L. R., and R. C. B. Utzurrum. 1992. A review of the conservation
     status of Philippine land mammals. Association of Systematic Biologists
     of the Philippines Communications (1991) 3:1-13.
Heaney, L. R. 1993. Biodiversity patterns and the conservation of mammals
     in the Philippines. Asia Life Sciences, 2:261-274.
Heaney, L. R., D. S. Balete, and A. T. L. Dans. 1997. Terrestrial Mammals.
     Pp. 116-144.In Wildlife Conservation Society of the Philippines. Philippine
     Red Data Book. Bookmark, Manila. 240 pp.
Heaney, L and R. A. Mittermeier 1997. The Philippines. In: R. A. Mittermeier,
     P. Robles Gil and C.G. Mittermeier (Eds.). Megadiversity, Earth's
     Biologically Wealthiest Nations. CEMEX, Monterrey, Mexico, pp. 236-255.
Heideman, P. D. 1988. The timing of reproduction in the fruit bat,
     Haplonycteris fischeri(Pteropodidae): geographic variation and delayed
     development. Journal of Zoology, London 215: 577-595.
Heideman, P. D. 1989. Delayed development in Fischer's pygmy fruit bat,
     Haplonyceris fischeri, in the Philippines. Journal of Reproduction and
     Fertility 85: 363-382. Heideman, P. D., and K. R. Erickson. 1987. The
     climate and hydrology of the Lake Balinsasayao watershed, Negros
     Oriental, Philippines. Silliman Journal 34: 82-107.
Heideman, P. D., & L. R. Heaney. 1989. Population biology and estimates
     of abundance of fruit bats (Pteropodidae) in Philippine submontane
     rainforest. Journal of Zoology (London) 218: 565-586.
Holttum, R. E. 1963. Cyatheacaea. Flora Malesiana II, 1:65-176.
Ingle, N. R. 1992. The natural history of bats on Mt. Makiling, Luzon Island,
     Philippines. Silliman Journal 36: 1-26.
Ingle, N. R. 1993. Vertical stratification of bats in a Philippine rainforest.
     Asia Life Sciences 2: 215-222.
Ingle, N. R. and L. R. Heaney. 1992. A key to the bats of the Philippine
     Islands. Fieldiana Zoology new series 69:1-44.
Karnow, S. 1989. In our image, America’s empire in the Philippines.
     Random House, New York. 494 pp.
Kummer, D. M. 1992. Deforestation in the postwar Philippines. University
     of Chicago Press. 177 pp.
Kummer, D. M. and B. L. Turner II. 1994. The human causes of
     deforestation in Southeast Asia. Bioscience 44:323-328.
     Lepiten, M. V. 1997. The Mammals of Siquijor Island, central
     Philippines. Sylvatrop (1995), 1 & 2: 1-17.
Magsalay, P. M. 1993. Rediscovery of four Cebu endemic birds
     (Philippines). Asia Life Sciences 2:141-148.
Manalo, E. B. 1956. The distribution of rainfall in the Philippines. Philippine
     Geographical Journal 4: 104-166.
Merrill, E. D. 1923-26. An enumeration of Philippine flowering plants. Manila,
     Bureau of Printing.
Merrill, E. D. 1945. Plant life of the Pacific World. MacMilan Co., New York.
     295 pp.
Musser, G. G., & P. W. Freeman. 1981. A new species of Rhynchomys
     (Muridae) from the Philippines. Journal of Mammalogy 62: 154-159.
Musser, G. G., and L. R. Heaney. 1992. Philippine rodents: definitions
     of Tarsomys and Limnomys plus a preliminary assessment of
     phylogenetic patterns among native Philippine murines (Murinae,
     Muridae). Bulletin of the American Museum of Natural History 211:1-138.
Musser, G. G., L. R. Heaney, and B. R. Tabaranza, Jr.. 1998. Philippine rodents:
     Redefinitions of known species of Batomys (Mammalia, Muridae) and
     description of a new species from Dinagat Island, Philippines. American
     Museum Novitates 3237:1-51.
Myers, N. 1988. Environmental degradation and some economic consequences
     in the Philippines. Environmental Conservation, 15: 205-214.
Myers, N. 1984. The primary source, tropical forests and our future. W. W.
     Norton & Co., New York. 399 pp.
Myers, N. 1993. Ultimate security: the environmental basis of political stability.
     W. W. Norton & Co., New York. 308 pp.
National Mapping and Resource Information Authority. 1988. Sheet maps,
     1:250,000, based on satellite images from the Swedish Space
     Corporation. Manila, 53 sheets.
Oliver, W. L. R., C. R. Cox, and C. P. Groves. 1993b. The Philippine
     warty pigs (Sus philippensis and Sus cebifrons. In Oliver, W. L. R.,
     ed., Pigs, Peccaries, and Hippos: Status survey and conservation action
     plan. IUCN, Gland, 202 pp.
Oliver, W. L. R., M. L. Dolar, and E. Alcala. 1992. The Philippine spotted deer,
     Cervus alfredi Sclater, conservation program. Silliman Journal 36: 47-54.
Oliver, W. L. R., C. R. Cox, P. C. Gonzales, and L. R. Heaney. 1993. Cloud
     rats in the Philippines - preliminary report on distribution and status. Oryx
Oliver, W. L. R and L. R. Heaney. 1996. Biodiversity and conservation in the
     Philippines. International Zoo News 43:329-337.
Peterson, A. T., and L. R. Heaney. 1993. Genetic differentiation in Philippine
     bats of the genera Cynopterus and Haplonycteris. Biological Journal of
     the Linnean Society 49: 203-218.
Porter, G. and D. J. Ganapin, Jr. 1988. Resources, population, and the
     Philippines’ future; a case study. World Resources Institute, Washington.
     68 pp.
Rabor, D. S. 1955. Notes on mammals and birds of the central northern
     Luzon highlands, Philippines. Pt. 1. Notes on mammals. Silliman Journal
     2: 193-218.
Rabor, D. S. 1966. A report on the zoological expeditions in the Philippines for
     the period 1961-1966. Silliman Journal 13: 604-616.
Rabor, D. S. 1977. Philippine Birds and Mammals. University of Philippines
     Press, Quezon City, 283 pp.
Regalado, J. C. 1995. Revision of the Philippine Medinilla. Blumea 40:113-193.
Remigio, A. A. Jr. 1993. Philippine forest resource policy in the Marcos and Aquino
     governments: a comparative assessment. Global Ecology and Biogeography
     Letters 3:192-193.
Repetto, R. 1988. The forest for the trees? Government policies and the misuse of
     forest resources. World Resources Institute, Washington. 105 pp.
Rickart, E. A., L. R. Heaney, D. S. Balete, and B. R. Tabaranza, Jr. 1998.
     A review of the genera Crunomys and Archboldomys (Rodentia,
     Muridae, Murinae) with descriptions of two new species from the Philippines.
     Fieldiana Zoology new series 89:1-24.
Rickart, E. A., L. R. Heaney, and R. B. Utzurrum. 1991. Distribution and
     ecology of small mammals along an elevational transect in southeastern
     Luzon, Philippines. Journal of Mammalogy 72:458-469.
Rickart, E. A. 1993. Diversity patterns of mammals along elevational and
     diversity gradients in the Philippines: implications for conservation.
     Asia Life Sciences 2:251-260.
Samson, D. A., E. A. Rickart, and P. C. Gonzales. 1997. Ant diversity and
     abundance along an elevational gradient in the Philippines. Biotropica
     29: 349-363.
Santos, J. V. 1986. Philippine bamboos. In Guide to Philippine Flora and Fauna
Tan, B. C., E. S. Fernando, and J. P. Rojo. 1986. An updated list of endangered
     Philippine plants. Yushiana 3(2):1-5.
Tan, B. C. and Z. Iwatsuki. 1991. A new annotated Philippine moss checklist.
     Harvard Papers in Botany 3:1-64.
Utzurrum, R. C. B. 1992. Conservation status of Philippine fruit bats
     (Pteropodidae). Silliman Journal 36: 27-45.
Utzurrum, R. C. B. 1995. Feeding ecology of Philippine fruit bats: patterns of
     resource use and seed dispersal, pp. 63-77. In Racey, P. A., and
     S. M. Swift (eds.), Ecology, Evolution, and Behaviour of Bats. Symposia
     of the Zoological Society of London 67: 1-421.
Vitug, M. D. 1993. Power from the forest: the politics of logging. Philippine
     Center for Investigative Journalism, Manila. 277 pp.
Whitmore, T. C. 1984. Tropical Rain Forests of the Far East. Clarendon
     Press, Oxford, 352 pp.
Wildlife Conservation Society of the Philippines. 1997. Philippine Red Data
     Book. Bookmark, Inc., Makati City. 262 pp.
World Bank. 1989. Philippines: Environment and Natural Resource Management
     Study. The World Bank, Washington. 170 pp.

The Field Museum thanks the above individuals and agencies for permission to reproduce copyrighted materials on this site.
The original reference may be cited as follows:

Heaney, L. R. and J. C. Regalado, Jr. 1998. Vanishing Treasures of the Philippine Rain Forest. The Field Museum, Chicago. 88 pp.

© 2007 The Field Museum, All Rights Reserved
1400 S. Lake Shore Dr, Chicago, IL 60605-2496


  1. This comment has been removed by a blog administrator.

  2. This comment has been removed by a blog administrator.

  3. This comment has been removed by a blog administrator.

  4. This comment has been removed by a blog administrator.

  5. This comment has been removed by a blog administrator.

  6. For the better experience of audio-listening, HTC Desire C provides you with Beats Audio.

    If you wish to answer a quick question, again, use your Smartphone to go online and search
    for that quick answer. It can also be used
    to quickly search Google or Wikipedia.

    Here is my web-site - galaxy s4