Lawrence Heaney

For several centuries, biologists have pointed to island archipelagos as natural laboratories where biological processes can be studied.  My research focuses on the evolutionary origin, ecological maintenance, and conservation of natural biological diversity in two areas: Southeast Asia, especially the Philippines, and the Intermountain West of the United States.  I study mammals that live on land - on the ground, in trees, and in the air.

Philippine Mammal Project

Research in the Philippines has absorbed much of my time since 1981, when I made my first trip to conduct field studies at several locations on Luzon and Negros islands.  Then, as now, I sought to understand the processes that influence the number of species that live on a given island; the distribution of species within the archipelago; the relationships of species that are unique (endemic) to the archipelago or some limited part of the archipelago; the processes of colonization, speciation, and extinction that have taken place; the impact of past and present climate on the diversity of mammals; and the role of the geological history of the archipelago in shaping the current mammal fauna.  I expected the project to last about five years; that was 30 years ago. Along the way, we have found a great many things that we did not expect - and each has added important questions that must be answered to achieve those initial (and increasingly complex) goals.

The adjacent map shows the locations of the primary study areas where we have obtained detailed information.  In each of these areas, we have conducted standardized surveys of the mammals, using a set of procedures that are comparable across all locations.  In each area, we endeavor to sample in such a way that we obtain as complete a list of mammal species that are present as is possible.  This requires that we sample along the entire elevational gradient (from bottom to top of the mountain), along disturbance gradients (from agricultural fields to old-growth forest), and in any special habitats (such as caves).  Conducting a full survey in each area requires from a week (in the simplest of situations) to three months, for a crew of five to eight people.  Most of the field work for the last 20 years has been conducted in collaboration with Danny Balete, Eric Rickart, Phillip Alviola, Aloy Duya, Liza Duya, and Sweepea Veluz.

When we began the project, the mammal fauna of the Philippines was thought to be the best known in SE Asia, in terms of having a complete list of species that are present and basic information on distribution and ecology.  We now know that was spectacularly wrong; since 1981, about fifty species of previously unknown mammals have been formally described from the Philippines, all but twelve by our research team, and we are studying specimens of what appear to be several dozen more (for more information, check out the Synopsis of Philippine Mammalswebsite).  Few countries have seen similar numbers of new species of mammals, and all of them are much larger in area, and since all of the new species are endemic, the Philippines now ranks as having among the highest concentrations of unique species of any country.

Most of these discoveries have taken place in the context of surveys in areas selected because they fit predictions from biogeographical models.  In brief, our models predict that every island (or set of islands) that is surrounded entirely by deep water (over 120 m) will have endemic mammal species.  Thus, islands as large as Luzon or as small as Lubang, Sibuyan and Camiguin have unique species of mammals; and the number of species is correlated with island area.  Within the larger islands, such as Luzon, we have learned that each isolated mountain range (surrounded by areas below about 200 m elevation) is also a unique center of mammalian diversity, and the higher the mountain the more endemic mammal species are present.  Even small ranges, such as Mts. Banahaw-San Cristobal, have at least five endemic species.  We now know that there are at least 9 mountain centers of endemism on Luzon Island, as the result of our focused field and museum studies beginning in 2000.  Each of these individual centers of endemism hold as many or more unique species than most individual countries in Europe.

It was long thought that lowland tropical rainforest holds the largest number of species of any given group.  We have learned that this is true for bats, but not for other groups of mammals in the Philippines and many other parts of the world.  On any individual mountain range, the number of species in the lowlands is small, and rises gradually with increasing elevation, to about 2000 to 2200 meters, at which point it ceases to rise, then gradually begins to decrease as elevation increases still further.  We have learned that most of the species endemic to a given mountain range occur at high elevation, in cool, wet mossy forest.  This has led us to studies of the impact of climate, vegetation, soil conditions, competitors, and predators that might be responsible for this pattern.

Using DNA sequence data, we have been able to confirm earlier studies based on morphology that most Philippine species of mammals are closely related to other Philippine mammals; in other words, most species are members of an entire branch on the “tree of life” that occurs only in the Philippines.  Thus, the ca. 50 species of “earthworm mice” (species in the genera Apomys, Archboldomys, Chrotomys, Soricomys,, and Rhynchomys) are a branch that lives nowhere else, and have diversified from a single ancestor species that we estimate arrived in the Philippines 7 to 8 million years ago.  The 15 or more species of cloud rats (Batomys, Carpomys, Crateromys, Musseromys, and Phloeomys) form another branch found only in the Philippines; and many other smaller branches are also unique to the Philippines.  Clearly, although their ancestors arrived millions of years ago from the Asian mainland, speciation within the Philippines has produced most of the mammalian diversity that is present today.  Much of this research has been done in collaboration with Sharon Jansa and Scott Steppan.

Taken together, these data indicate that colonization by mammals from outside the Philippines has been rare, and colonization between islands within the archipelago has been more common, but still a rather rare event best measured on a scale of hundreds of thousands to millions of years.  On that scale, the geology of the archipelago has been dynamic, with volcanoes erupting, some islands eroding away and others merging together, and “continental drift” (plate tectonics) causing divergent sets of islands to move into proximity.  It is a complex picture that we are gradually uncovering, with the potential to become an even better example of the processes of evolution than the far better-known Galapagos Islands.

With a current population of about 105 million citizens, the Philippines is one of the most heavily populated countries in the world.  Use of natural resources, through logging, mining, and agriculture, has often been very poorly managed, resulting in great environmental instability.  Many of the people are poor farmers, adding to stress on natural ecosystems (to learn more, see our website of Vanishing Treasures of the Philippine Rainforest).  Our team has responded in several ways to the need for conservation action.  First, we work actively and closely with the Philippine Department of Natural Resources (DENR), especially the Biodiversity Management Bureau, relaying to them the results of all of our studies, so that they have the most up-to-date information available.  With the DENR as a partner, in 2010 we launched the Synopsis of Philippine Mammalswebsite to provide a complete summary of the entire fauna of the country, written in a way that makes it useful to the general public, government officials, and research scientists.  Our studies of specific areas have provided much of the basis for declaring new national parks, including several that are currently “in the pipeline”, and for improved management at many others.  We have participated in the initial development and periodic updates of the official DENR list of threatened species of mammals, often providing the bulk of the information on the species.  We also have developed educational materials, including a series of posters with attractive drawings of the many endemic species of mammals, and guides to the mammals of particular national parks, all of which you can access here.  The project has also provided training opportunities to over 75 people within the Philippines, and to about 25 at the Field Museum in Chicago.

As one of the project’s most important contributions to Philippine conservation, in 1991 we obtained funding from the MacArthur Foundation that allowed the establishment of the Wildlife Conservation Society of the Philippines, which is an organization of over 500 members who share an active interest in research and management of wild organisms in the Philippines.  The WCSP provides a forum for exchange of ideas, data, questions, policies, and procedures among members from academia, non-government organizations, government officials, and concerned citizens through annual conferences and workshops.

This project has benefited greatly by interactions with many collaborators, based at organizations in the Philippines, United States, and around the globe.  The primary institutions have been the Department of Environment and Natural Resources, including the Biodiversity Management Bureau and the regional offices of the DENR; the Philippine National Museum; offices of the governors and mayors in all of our study areas; National Commission for Indigenous People; University of the Philippines (Diliman, Los Banos, and Baguio campuses); Silliman University; Leyte State University; Ateneo de Manila University; Conservation International - Philippines; the Haribon Foundation; the U.S. National Museum of Natural History; Utah Museum of Natural History; Geneva Museum of Natural History; Florida State University; University of Kansas; Lawrence University; University of Michigan; and University of Minnesota.  Primary collaborators in recent years have been Phillip Alviola; Danilo Balete; Louella Dolar; Mariano Roy Duya; Melizar Duya; Jacob Esselstyn; Nina Ingle; Sharon Jansa; Guy Musser; Eric Rickart; Manuel Ruedi; Jodi Sedlock; Scott Steppan; and Maria Josefa Veluz.  We thank the many people who have graciously provided their assistance and hospitality in the Philippines to make this project possible.  And finally, our deepest thanks to the Negaunee Foundation and Brown family for their support of our efforts to understand and protect the astounding mammal fauna of the Philippines.

Mammals of the “Sky Islands” of Utah and Nevada

In collaboration with my colleagues Eric Rickart, Curator of Vertebrates and Rebecca Rowe, Postdoctoral Researcher, at the Utah Museum of Natural History,  I have investigated the diversity and distribution patterns of the small mammals that live on the “sky islands” of the Intermountain West in Utah and Nevada.  As with the Philippine Mammal Project, we seek to understand the factors that influence patterns of species richness, both past and present.  We have conducted detailed, standardized surveys of over a dozen small mountain ranges to determine the distribution of species along the elevational gradient from dry desert at the bottom of most mountains to cool, moist conifer forest at the top.  DNA samples from the animals we capture are used to study the evolutionary origin and patterns of diversification of the fauna.  Whenever possible, we re-sample in places where mammalogists conducted similar surveys in the period of ca. 1910-1930.