Melizar V. Duya

Chapter 1: Seven New Species and a New Subgenus of Forest Mice (Rodentia: Muridae: Apomys) from Luzon Island

Abstract Surveys of small mammals on carefully selected mountains and mountain ranges on Luzon Island, Philippines, since 2000 have led to the discovery of seven previously unknown species of forest mice, Apomys, a remarkable radiation on just a portion of one island. On the basis of morphological and cytochrome (cyt) b DNA sequence data presented here, we propose a new subgenus, Megapomys, to include the large-bodied members of the genus, which form a monophyletic unit of relatively large mice (averaging ca. 65–110 g) with tails about as long as or slightly shorter than the length of the head and body; all of these species forage on the ground. Other members of the genus are assigned to the subgenus Apomys; they are smaller (ca. 18–41 g), have long tails, and usually or often forage above the ground surface. Members of the subgenus Megapomys include four previously recognized species (A. abrae, A. datae, A. gracilirostris, and A. sacobianus) and the seven new species described here (A. aurorae, A. banahao, A. brownorum, A. magnus, A minganensis, A. sierrae, and A. zambalensis). All occur in northern and central Luzon Island, with the exception of one species that occurs on Mindoro Island; none is present in southern Luzon. Each species can be distinguished both morphologically and genetically. Although there are few records of Megapomys below 500 m elevation, they are common above about 1000 m, and some species occur near the peaks of the highest mountains on Luzon (i.e., up to nearly 2900 m). On four mountain ranges, two species of the subgenus co-occur, one at lower and one at higher elevations, although there is usually some syntopic overlap. Sister-species usually occur allopatrically in different mountain ranges, with one possible exception. Some of these species occur in areas not previously known to support endemic mammals, indicating that these areas are previously unrecognized areas of mammalian endemism where further study is warranted.

Archboldomys (Muridae: Murinae) Reconsidered: A New Genus and Three New Species of Shrew Mice from Luzon Island, Philippines

ABSTRACT Shrew mice of the genus Archboldomys are poorly known members of an endemic clade of vermivorous/insectivorous murid rodents confined to Luzon Island, Philippines. Three species of these small, ground-living, diurnal mice were previously known, all from a handful of specimens from a few localities. The pattern of morphological and genetic differentiation among additional specimens of shrew mice from our recent field surveys in the Central Cordillera and Sierra Madre mountains of Luzon document the presence of two distinct species groups within Archboldomys as previously defined, as well as three new species. Gene-sequence data from the mitochondrial cytochrome b and nuclear IRBP genes confirm the existence of six distinct species, but also show that Archboldomys, as previously defined, is composed of two clades that are not sister taxa. Reevaluation of the presumed morphological synapomorphies among these shrew mice, together with analyses of karyological and gene-sequence data, support the following: (1) erection of Soricomys, new genus; (2) transfer of A. kalinga and A. musseri to Soricomys; and (3) recognition of Archboldomys maximus, n. sp., Soricomys leonardocoi, n. sp., and Soricomys montanus, n. sp. The new genus and species are described, and their phylogenetic relationships, biogeography, and conservation are discussed.

Conservation Genetics of the Philippine Tarsier: Cryptic Genetic Variation Restructures Conservation Priorities for an Island Archipelago Primate

Establishment of conservation priorities for primates is a particular concern in the island archipelagos of Southeast Asia, where rates of habitat destruction are among the highest in the world. Conservation programs require knowledge of taxonomic diversity to ensure success. The Philippine tarsier is a flagship species that promotes environmental awareness and a thriving ecotourism economy in the Philippines. However, assessment of its conservation status has been impeded by taxonomic uncertainty, a paucity of field studies, and a lack of vouchered specimens and genetic samples available for study in biodiversity repositories. Consequently, conservation priorities are unclear. In this study we use mitochondrial and nuclear DNA to empirically infer geographic partitioning of genetic variation and to identify evolutionarily distinct lineages for conservation action. The distribution of Philippine tarsier genetic diversity is neither congruent with expectations based on biogeographical patterns documented in other Philippine vertebrates, nor does it agree with the most recent Philippine tarsier taxonomic arrangement. We identify three principal evolutionary lineages that do not correspond to the currently recognized subspecies, highlight the discovery of a novel cryptic and range-restricted subcenter of genetic variation in an unanticipated part of the archipelago, and identify additional geographically structured genetic variation that should be the focus of future studies and conservation action. Conservation of this flagship species necessitates establishment of protected areas and targeted conservation programs within the range of each genetically distinct variant of the Philippine tarsier.

Chapter 3: The Mammals of the Mingan Mountains, Luzon Evidence for a New Center of Mammalian Endemism

Abstract We conducted an elevational transect survey of mammals on the highest peak in the Mingan Mountains of Aurora and Nueva Ecija provinces in the central Sierra Madre Range of Luzon from May to August 2006 and documented 35 species of mammals. These included one shrew (Soricidae), six fruit bats (Pteropodidae), one ghost bat (Megadermatidae), three horseshoe bats (Rhinolophidae), three roundleaf bats (Hipposideridae), four evening bats (Vespertilionidae), one macaque (Cercopithecidae), 12 mice and rats (Muridae), two civets (Viverridae), one wild pig (Suidae), and one deer (Cervidae). Our survey of this small, poorly known mountain range included the discovery of two new species of forest mice (Apomys), a new species of shrew-mouse (Archboldomys), a probable new species of shrew-rat (Rhynchomys), and an unidentified species of tube-nosed bat (Murina). Species richness of bats decreased with increasing elevation, whereas that for native non-volant small mammals increased with increasing elevation up to 1677 m, then declined at 1681 and 1785 m. Statistically significant diel activity and bait preferences were observed among the native non-volant small mammals. Only the two species of small forest mice (Apomys microdon and A. musculus) were captured exclusively above ground; the other non-volant small mammals were nearly always captured on the ground. The Mingan Mountains, with either three or four endemic species, are clearly a significant center of mammalian endemism, deserving of conservation.

New Forest Gecko (Squamata; Gekkonidae; Genus Luperosaurus) from Mt. Mantalingajan, Southern Palawan Island, Philippines

Abstract We describe a new species of Luperosaurus from Mt. Mantalingajan, southern Palawan Island, Philippines. The new species is distinguished from all other species of Luperosaurus by the combination of its large body size (81.3 mm for the single male specimen), near complete absence of interdigital webbing, absence of cutaneous expansions on limbs except for a minute flap on the posterior margins of the hind limbs, the presence of differentiated, moderately enlarged chin shields, 40 precloacofemoral pore-bearing scales, the limitation of scattered flattened dorsal tubercles to only the posterior portions of the torso, absence of spinose or recurved ornamental tubercles on the head and nuchal region, and convex to posteriorly raised tubercles clustered at the posterior margins of caudal tail annuli. Because the new species shares features with species in both species of Luperosaurus and Gekko, we compare the new species to (and distinguish it from) both genera. The new species is distinguished from all Southeast Asian Gekko by the combination of its smaller body size, relatively short, stout limbs, presence of only moderately enlarged, slightly imbricate ventral body scales, differentiated postmentals not highly elongate, dorsal body tubercles limited to posterior trunk and not arranged in rows, absence of enlarged, spinose tubercles on the limbs and tail, and tail encircled by small scales (enlarged subcaudals absent). The new species further emphasizes the biogeographic distinctiveness (from Sundaland fauna) and level of vertebrate endemism of Palawan Island and underscores the degree to which the biodiversity of the Philippines is not fully understood.

A New Species of Stream Frog (Sanguirana) from the Mountains of Luzon Island, Philippines

Abstract:  We describe a distinctively patterned new species of cascade stream frog from the mountains of Nueva Vizcaya and Aurora provinces, Luzon Island. The new species belongs to the genus Sanguirana, the definition of which we expand to include all Philippine species previously referred to the Rana (Hylarana) everetti complex. The new species is distinguished from other members of the genus by its possession of a bright yellow-green dorsum with conspicuous orange flower-shaped spots in females, bright white, postaxial dermal flanges on the limbs, green-to-purple flank transition, and a highly tuberculate, white venter, in addition to the absence of a dark canthal stripe. The new species is known only from high-gradient, cascading mountain streams between elevations of 750 and 1450 m in mature secondary forest and minimally disturbed primary forests. The discovery of such a distinctive new species emphasizes the relatively high degree to which endemic anuran diversity in the Philippines is still underestimated and underappreciated.

Chapter 4: Diversity of Small Mammals in Montane and Mossy Forests on Mount Cetaceo, Cagayan Province, Luzon

Abstract We surveyed non-volant mammals in montane (1300 and 1400 m) and mossy forest (1500 and 1550 m) on Mount Cetaceo in the northern Sierra Madre of northeast Luzon in 2004 and 2005. We recorded a total of 12 species of mammals, including one shrew (Soricidae), seven murid rodents (Muridae), one deer (Cervidae), one wild pig (Suidae), one macaque (Cercopithecidae), and one civet (Viverridae). In this paper, we present the first ecological data on two recently discovered species endemic to northeast Luzon, Archboldomys musseri and Apomys sierrae. We captured only three species at 1300 m; captured five species at 1400 m; captured or inferred six species at 1500 m; and documented four species at 1550 m. Combined with an earlier study at 960 m (3 species), these results imply that species richness might increase from the lowlands to ca. 1500 m. The small number of sampling localities prevented strong statistical inference, but percent trap success with roasted coconut bait declined with increased elevation along our short transect, and trap success with live earthworm bait increased along the transect, so that overall trap success varied little along the transect. The most abundant species, A. sierrae, significantly preferred earthworm bait and was significantly more abundant in mossy forest than in montane forest. The percentage of diurnal captures along the transect increased with increased elevation, from a low of 0% at 1300 m to nearly 11% at 1550 m, even though no species showed significantly more diurnal than nocturnal/crepuscular activity. These patterns are similar to those on other mountain peaks on Luzon. The number of native species recorded on Mt. Cetaceo (7), plus one species recorded in the nearby lowlands, is similar to the number expected on the basis of the peak elevation of Mt. Cetaceo, supporting the hypothesis that the diversity of small mammals on a given mountain on Luzon is correlated with the elevation of the peak. Large mammals on Mt. Cetaceo are actively hunted; because they use both lowland and montane/mossy forest habitats, they may be threatened by the combination of agricultural expansion in the lowlands and unregulated hunting.

Chapter 2: Mammalian Diversity Patterns on Mount Palali, Caraballo Mountains, Luzon

Abstract In 2005 and 2007, we conducted surveys of mammals along an elevational transect on Mount Palali (peak 1707 m) in the Caraballo Mountains, a poorly known mountain range on Luzon Island, Philippines. The surveys covered eight localities representing habitats from lowland agroforest and regenerating disturbed lowland rainforest at 780 m to mossy forest near the peak. We recorded 24 species, including one native shrew, one non-native shrew, five fruit bats, seven insectivorous bats, one monkey, six native rodents, two civets, and one pig. One species of Apomys is the newly described A. sierrae, and two species of Chrotomys are potentially undescribed species. Elevational patterns varied among mammals: bats were most diverse in the lowlands, native nonvolant small mammals had almost equal richness along the entire elevational transect, and most species of large mammals were present at all elevations. Bait attractiveness and diel activity pattern differed among native nonvolant small mammals: Apomys microdon and Rattus everetti were nocturnal and attracted to coconut baits, Chrotomys sp. 1 and 2 were mostly nocturnal and favored earthworms, Crocidura grayi showed no bait preference and was active during day and night, and A. sierrae showed no bait preference and was most active at night. The non-native Suncus murinus was restricted to highly disturbed areas at 780 m, whereas all native nonvolant small mammals were present in both degraded and undisturbed forest, supporting the hypothesis that non-native small mammals are not successful in invading native habitats on oceanic islands when the native community of small mammals is diverse. We conclude that all three rainforest types at all elevations, including newly regenerating forest, provide important habitat for mammals on Mount Palali.