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The Philippine archipelago hosts an exceptional diversity of murid rodents that have diversified following several independent colonization events. Here, we report the discovery of a new species of rodent from Mt. Kampalili on eastern Mindanao Island. Molecular and craniodental analyses reveal this species as a member of a Philippine "New Endemic" clade consisting of Tarsomys , Limnomys , and Rattus everetti (tribe Rattini). This new species of "shrew-mouse" is easily distinguished from its relatives in both craniodental and external characteristics including a long, narrow snout; small eyes and ears; short, dark, dense fur dorsally and ventrally; stout body with a tapering, visibly haired tail shorter than head and body length; stout forepaws; bulbous and nearly smooth braincase; narrow, tapering rostrum; short incisive foramina; slender mandible; and narrow, slightly opisthodont incisors. This new genus and species of murid rodent illustrates that murids of the tribe Rattini have exhibited greater species and morphological diversification within the Philippines than previously known and provides evidence that Mt. Kampalili represents a previously unrecognized center of mammalian endemism on Mindanao Island that is deserving of conservation action. [ABSTRACT FROM AUTHOR]

Island radiations represent unique evolutionary histories in unique ecological contexts. These radiations provide opportunities to investigate ecological diversification in groups that typically exhibit niche partitioning among their constituents, including partitioning of food resources. DNA metabarcoding produces finer levels of diet identification than traditional methods, allowing us to examine dietary niche partitioning in communities or clades in which species share superficially similar diets. Here, we use DNA metabarcoding to investigate dietary niche partitioning in an endemic radiation of mammals in the Philippines. Our data reveal niche partitioning as well as phylogenetically‐uncorrelated adaptive evolution in this small mammal community. Because 70% of the focal species belong to the tribe Chrotomyini, an endemic Philippine radiation of murid rodents that feed extensively on earthworms, this study sheds light on dietary adaptation and its role in the co‐occurrence of closely related species. Our results reveal fine‐scale resource partitioning within this community; our data provide compelling evidence for niche partitioning of diet that was masked by previous diet categories and will help in further dissecting the model adaptive radiation of endemic small mammals on Luzon. This study reinforces the notion that DNA metabarcoding can be a valuable tool for investigating both ecological relationships and evolutionary ecology at the community and phylogenetic level, respectively. [ABSTRACT FROM AUTHOR]

The 18 extant members of the Tribe Phloeomyini, the "cloud rats," constitute an endemic Philippine radiation of arboreal herbivores that range in size from ca. 18 g to 2.7 kg, most occurring in cloud forest above 1,200 m elevation. Although calibrated phylogenies indicate that the Phloeomyini is estimated to have begun diversifying within the Philippines by ca. 10–11 million years ago, no extinct fossil species have been described, severely limiting our understanding of this distinctive radiation. Our studies of fossil and subfossil small mammal assemblages from the lowland Callao Caves complex in NE Luzon, Philippines, have produced specimens of Phloeomyini that date from ca. 67,000 BP to the Late Holocene (ca. 4,000 to 2,000 BP). We identify three extinct species that we name as new members assigned to the genera Batomys , Carpomys , and Crateromys , distinguished from congeners by body size, distinctive dental and other morphological features, and occupancy of a habitat (lowland forest over limestone) that differs from the high-elevation mossy forest over volcanic soils occupied by their congeners. Batomys cagayanensis n. sp. is known only from two specimens from ca. 67,000 BP; Carpomys dakal n. sp. and Crateromys ballik n. sp. were present from ca. 67,000 BP to the Late Holocene. These add to the species richness and morphological diversity of this endemic Philippine radiation of large folivores, and show specifically that the lowland fauna of small mammals on Luzon was more diverse in the recent past than it is currently, and that Luzon recently supported five species of giant rodents (ca. 1 kg or more). All three occurred contemporaneously with Homo luzonensis , and two, the new Carpomys and Crateromys , persisted until the Late Holocene when multiple exotic mammal species, both domestic and invasive, were introduced to Luzon, and new cultural practices (such as making pottery) became evident, suggesting that modern humans played a role in their extinction. [ABSTRACT FROM AUTHOR]

Aim: To determine the historical dynamics of colonization and whether the relative timing of colonization predicts diversification rate in the species‐rich, murine rodent communities of Indo‐Australia. Location: Indo‐Australian Archipelago including the Sunda shelf of continental Asia, Sahul shelf of continental Australia, the Philippines and Wallacea of Indonesia. Taxon: Order Rodentia, Family Muridae. Methods: We used a fossil‐calibrated molecular phylogeny and Bayesian biogeographical modelling to infer the frequency and temporal sequence of biogeographical transitions among Sunda, Sahul, the Philippines and Wallacea. We estimated diversification rates for each colonizing lineage using a method‐of‐moments estimator of net diversification and Bayesian mixture model estimates of diversification rate shifts. Results: We identified 17 biogeographical transitions, including nine originating from Sunda, seven originating from Sulawesi and broader Wallacea and one originating from Sahul. Wallacea was colonized eight times, the Phillipines five times, Sunda twice and Sahul twice. Net diversification rates ranged from 0.2 to 2.12 species/lineage/My with higher rates in secondary and later colonizers than primary colonizers. The highest rates were in the genus Rattus and their closest relatives, irrespective of colonization history. Main Conclusions: Our inferences from murines demonstrate once again the substantial role of islands as sources of species diversity in terrestrial vertebrates of the IAA with most speciation events occurring on islands. Sulawesi and broader Wallacea have been a major source of colonists for both island and continental systems. Crossings of Wallace's Line were more common than subsequent transitions across Lydekker's Line to the east. While speciation following colonization of oceanic archipelagos and large islands is consistent with adaptive radiation theory and ideas regarding ecological opportunity, we did not observe a strong signal of incumbency effects. Rather, subsequent colonists of landmasses radiated unhindered by previous radiations. [ABSTRACT FROM AUTHOR]

Arboreal locomotion allows access to above-ground resources and might have fostered the diversification of mammals. Nevertheless, simple morphological measurements that consistently correlate with arboreality remain indefinable. As such, the climbing habits of many species of mammals, living and extinct, remain speculative. We collected quantitative data on the climbing tendencies of 20 species of murine rodents, an ecologically and morphologically diverse clade. We leveraged Bayesian phylogenetic mixed models (BPMMs), incorporating intraspecific variation and phylogenetic uncertainty, to determine which, if any, traits (17 skeletal indices) predict climbing frequency. We used ordinal BPMMs to test the ability of the indices to place 48 murine species that lack quantitative climbing data into three qualitative locomotor categories (terrestrial, general and arboreal). Only two indices (both measures of relative digit length) accurately predict locomotor styles, with manus digit length showing the best fit. Manus digit length has low phylogenetic signal, is largely explained by locomotor ecology and might effectively predict locomotion across a multitude of small mammals, including extinct species. Surprisingly, relative tail length, a common proxy for locomotion, was a poor predictor of climbing. In general, detailed, quantitative natural history data, such as those presented here, are needed to enhance our understanding of the evolutionary and ecological success of clades. [ABSTRACT FROM AUTHOR]

The Ilin cloud rat Crateromys paulus, identified from a single individual in 1981 and collected from an undocumented location in Ilin Island, Mindoro, Philippines, is now considered to be ‘‘data deficient’’ and possibly extinct. 96 murid dental fossil remains were recently recovered within a two-meter excavation of well stratified and chronometrically dated deposits at the archaeological sites of Bubog I and Bubog II on Ilin Island. Research on these well-preserved murid rodent remains confirms the past presence of C. paulus on Ilin Island and describes for the first time variability in dental morphology of this species. The succession of fossils within the detailed stratigraphic sequence also provides us with information on C. paulus throughout the Holocene and on its possible recent extinction. [ABSTRACT FROM AUTHOR]

We describe a new species of Batomys from Mt. Isarog, southern Luzon. Morphological and genetic studies of newly obtained specimens of Batomys granti from the type locality on Mt. Data and other high mountains in the Central Cordillera of northern Luzon, and previously referred specimens from Mt. Isarog on the southern peninsula of Luzon, support the separation of the population from Mt. Isarog as a distinct species that is sister to B. granti and demonstrate the existence of B. granti as a widespread species in the Cordillera. The new species occurs only in montane and mossy forest from 1350 m to 1800 m, and is separated from the nearest known population of B. granti by about 450 km. Limited ecological data indicate that it is a nocturnal herbivore. Recognition of this species raises the number of native murid species on Luzon to 44, and the number of species in the endemic Philippine cloud-rat clade to 18. The new species occurs within a national park that is not currently under threat. [ABSTRACT FROM AUTHOR]

During July 2011, a single Cordillera striped shrew-rat ( Chrotomys whiteheadi) was collected from the Philippines and its faeces examined for coccidian parasites. It harboured an eimerian that we describe here as new. Oocysts of Eimeria macarthuri sp. n. were spheroidal to subspheroidal with a bi-layered wall and measured (length × width, L × W) 18.2 × 17.0 μm, with an L/W ratio of 1.1. A micropyle, oocyst residuum and polar granule were absent. Sporocysts were ovoidal, 9.0 × 6.4 μm, with an L/W ratio of 1.3. A nipple-like Stieda body was present as well as a substieda body. A granular sporocyst residuum was present. To our knowledge, E. macarthuri represents the only coccidian ever described from a rodent of the Philippines. [ABSTRACT FROM AUTHOR]

Two previously unrecognized species of the genus Hymenolepis are described based on specimens obtained from murid rodent species Bullimus luzonicus, Apomys microdon, and Rattus everetti collected on Luzon Island, Philippines. Hymenolepis bicauda n. sp. differs from all known Hymenolepis spp. in relative position of the poral dorsal and ventral osmoregulatory canals, gravid uterus occupying less than half the length of proglottid, relatively few eggs, and the highly characteristic longitudinal split of proglottids at the end of the gravid strobila. Hymenolepis haukisalmii n. sp. differs from all known Hymenolepis spp. in the relative position of both poral and aporal dorsal and ventral osmoregulatory canals and uterus lacking dorsal and ventral diverticula. The shift in the relative position of the dorsal and ventral osmoregulatory canals was not known in Hymenolepis from rodents in other regions of the world and is reminiscent of the situation observed in Hymenolepis erinacei, parasitic in hedgehogs, and members of the genus Talpolepis, parasitic in moles. The cosmopolitan species Hymenolepis diminuta was the only member of the genus previously reported from the Philippines. [ABSTRACT FROM AUTHOR]

Murid rodents of the endemic genus Batomys are diverse and geographically widely distributed in the Philippines. Four species have been recognized: B. dentatus and B. granti on Luzon, B. salomonseni on several islands comprising the Mindanao faunal region, and B. russatus on Dinagat Island. A recent survey of small mammals in eastern Mindanao recorded the presence of Batomys on Mt. Hamiguitan, the only other documented occurrence of this genus on Mindanao Island outside of Mt. Kitanglad. Comparison of external morphology as well as cranial and dental features of the Hamiguitan Batomys with available specimens of congeners indicates that although it is closely allied to B. salomonseni, a number of distinct traits separate it from all its congeners, and we describe it as a new species, B. hamiguitan. This species corroborates the hypothesis that the island of Mindanao is comprised of multiple centers of endemism, of which the southeastern highland of Mt. Hamiguitan is one. [ABSTRACT FROM AUTHOR]

Rhynchomys belongs to a unique assemblage of Philippine rodents that exhibit a combination of primitive features as well as unique morphological specializations. These nocturnal "shrew-rats," with highly specialized vermivorous and insectivorous food habits, are endemic to Luzon Island. Analyses of external, cranial, and dental features support the recognition of 4 species, 2 of which are described in this paper. All are restricted to high-elevation habitats, about 1,100 m and above, in montane and mossy forest on northern, western, and southeastern Luzon. Habitat vicariance and subsequent divergence in isolation is the probable mode of diversification in Rhynchomys as well as in other murid clades whose members are restricted to high-elevation habitats. The discovery of locally endemic species of Rhynchomys both confirms the existence of multiple centers of endemism on Luzon and underscores the need to establish and maintain additional protected areas on the island. [ABSTRACT FROM AUTHOR]

The 22 genera and 64 species of rodents (Muridae: Murinae) distributed in the Philippine Islands provide a unique opportunity to study patterns and processes of diversification in island systems. Over 90% of these rodent species are endemic to the archipelago, but the relative importance of dispersal from the mainland, dispersal within the archipelago, and in situ differentiation as explanations of this diversity remains unclear, as no phylogenetic hypothesis for these species and relevant mainland forms is currently available. Here we report the results of phylogenetic analyses of the endemic Philippine murines and a wide sampling of murine diversity from outside the archipelago, based on the mitochondrial cytochrome b gene and the nuclear-encoded IRBP exon 1. Analysis of our combined gene data set consistently identified five clades comprising endemic Philippine genera, suggesting multiple invasions of the archipelago. Molecular dating analyses using parametric and semiparametric methods suggest that colonization occurred in at least two stages, one ca. 15 Mya, and another 8 to 12 million years later, consistent with the previous recognition of “Old” and “New” endemic rodent faunas. Ancestral area analysis suggests that the Old Endemics invaded landmasses that are now part of the island of Luzon, whereas the three New Endemic clades may have colonized through either Mindanao, Luzon, or both. Further, our results suggest that most of the diversification of Philippine murines took place within the archipelago. Despite heterogeneity between nuclear and mitochondrial genes in most model parameters, combined analysis of the two data sets using both parsimony and likelihood increased phylogenetic resolution; however, the effect of data combination on support for resolved nodes was method dependent. In contrast, our results suggest that combination of mitochondrial and nuclear data to estimate relatively ancient divergence times can severely compromise those estimates, even when specific methods that account for rate heterogeneity among genes are employed. [Biogeography; divergence date estimation; mitochondrial DNA; molecular systematics; Murinae; nuclear exon; Philippines; phylogeny.] [ABSTRACT FROM AUTHOR]

The murine genera Celaenomys and Chrotomys comprise a group of semifossorial, vermivorous rodents endemic to the Philippines. Analysis of variation within this group supports the recognition of 4 named species occurring on the large islands of Luzon and Mindoro, as well as our description of a 5th species from Sibuyan, a small island in the central Philippines that has remained isolated from the other islands by deep water channels. Examination of cytochrome-b gene sequence data from 4 of the 5 taxa indicates that Celaenomys silaceus may be basal and sister to the other taxa but morphological and chromosomal data do not support the recognition of Celaenomys as a separate genus. Analysis of the sequence data indicates a relatively early separation of the Sibuyan species and a later split between 2 species of Chrotomys on Luzon. Diversification of Chrotomys appears to have involved speciation associated with both habitat vicariance on Luzon and overwater dispersal to neighboring islands. Most of the members of this clade are restricted to mid- or high-elevation forests, have limited geographic ranges within the archipelago, and some may be imperiled due to loss of natural habitat. [ABSTRACT FROM AUTHOR]

A new species of murine rodent is described from the Mt. Kitanglad Range of north-central Mindanao Island, Philippines. It is the 2nd known species of Limnomys, a genus endemic to Mindanao. The new species differs from Limnomys sibuanus in having a relatively longer tail, larger hind feet, softer pelage with grayish-white ventral coloration, larger skull with a longer rostrum, larger auditory bullae, larger molars, and other cranial and dental features. The new species apparently is nocturnal, omnivorous, and terrestrial-scansorial in habit. The 2 species of Limnomys have overlapping elevational ranges on Mt. Kitanglad and are known to occur syntopically at I locality. All 11 species of murines native to Mindanao occur in the Mt. Kitanglad range, and 2 are local endemics. The local occurrence of congeners in 4 genera suggests a repeated pattern of vicariance speciation and dispersal among highland areas of Mindanao. [ABSTRACT FROM AUTHOR]

Presents a study that described the Camiguin bullimus also known as Muridae found in the Philippines. Evaluation of the morphological variation within the genus; Details on the external, cranial and dental measurements of the population of Bullimus; Materials and methods; Result of the study.

Pneumocystis fungi are opportunistic parasites of mammalian lungs whose evolution, ecology and host specificity in natural host populations remain poorly understood and controversial. Using an extensive collection of 731 lung samples from 27 rodent species sampled in five Southeast Asian countries, and nested PCR amplification of mitochondrial and nuclear genes, we investigated the host specificity and genetic structure of Pneumocystis lineages infecting wild rodents. We also identified the rodent species playing a central role in the transmission of these parasites using network analysis and centrality measurement and we characterized the environmental conditions allowing Pneumocystis infection in Southeast Asia using generalized linear mixed models. Building upon an unprecedented Pneumocystis sampling from numerous rodent species belonging to closely related genera, our findings provide compelling evidence that the host specificity of Pneumocystis lineages infecting rodents is not restricted to a single host species or genus as often presented in the literature but it encompasses much higher taxonomic levels and more distantly related rodent host species. The phylogenetic species status at both mitochondrial and nuclear genetic markers of at least three new Pneumocystis lineages, highly divergent from Pneumocystis species currently described, is also suggested by our data. Our models show that the probability of Pneumocystis infection in rodent hosts is positively correlated to environmental variables reflecting habitat fragmentation and landscape patchiness. Synanthropic and habitat-generalist rodents belonging to the Rattus, Sundamys and Bandicota genera played a role of bridge host species for Pneumocystis spreading in these heterogeneous habitats, where they can reach high population densities. These are critical findings improving our understanding of the ecology of these enigmatic parasites and the role played by cospeciation and host switches in their evolution. Our results also confirmed the role of land-use change and habitat fragmentation in parasite amplification and spillover in rodents., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The article offers information on greater white-toothed shrew, Crocidura russula, in Ireland. The large rodent is said to be larger than their native Irish cousins such as pygmy shrew which arrived on the island as a stowaway on a ship from North Africa and Continental Europe. It was also found in the mossy mountains in Tipperary, Limerick and the Philippines, found in Luzon and Mount Pulag. Such species had not been seen since its discovery in 1896 by a British biologist. According to Lawrence Heaney of the Field Museum in Chicago, Illinois, the animal is one of the most spectacular cases of adaptive radiation by mammals anywhere in the world.

Echinostoma ilocanum is widespread among the Philippine Islands but only 3% of over 30,000 stools were found to be positive for eggs. The prevalence rates were highest in Ilocana populations of northern Luzon; 11% of over 7,000 stools examined, however, rates as high as 44% were found. Pila luzonica is eaten uncooked by some people and metacercariae from these snails developed into adults in a number of laboratory animals. Rats, mice and hamsters were the most susceptible with patent infections developing as early as 7 days and lasting for 328 days. There seems to be little disease in humans and animals infected with this parasite.