125 research outputs found

    Systematics of oriental Pygmy squirrels of the genera Exilisciurus and Nannosciurus (Mammalia: Sciuridae)

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    http://deepblue.lib.umich.edu/bitstream/2027.42/56414/1/MP170.pd

    Morphology, genetics, and ecology of pocket gophers (genus Geomys) in a narrow hybrid zone

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    A population of hybrid pocket gophers (Geomys bursarius × G. lutescens) exists 1–2 km west of Oakdale, Antelope County, Nebraska, U.S.A. The hybrids occur in soil that has characteristics intermediate between that occupied by G. lutescens (sand) and by G. bursarius (silt loam); the vegetation associations on the different soils are Sandhills Prairie and Tall-grass Prairie, respectively, with mixed prairie on the intermediate soils. Hybrids are identifiable on the basis of both qualitative and quantitative morphological characteristics, allozymes and karyology. Concordance between morphological, allozymic, karyotypic and ecological data sets is very high. Hybrids appear to reproduce normally and survive well; i.e. they suffer no obvious loss of fitness. Backcrossing to either parental type is apparently rare. The parental species each support obligate parasitic lice (Geomydoecus: Trichodectidae) of different species; these species are not sister species. We suggest that hybrid zones resulting from primary and secondary contact may be distinguished by (1) concordance of clines in different character sets, (2) fossil and biogeographic data, and (3) parasite data. We conclude that this zone resulted from secondary contact, and that the zone is maintained either by selection against hybrids (less likely) or by hybrid superiority (more likely)

    Mammals of Dinagat and Siargao Islands, Philippines

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    http://deepblue.lib.umich.edu/bitstream/2027.42/57135/1/OP699.pd

    A new species of tube-nosed fruit bat (Nyctimene) from Negros Island, Philippines (Mammalia: Pteropodidae)

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    http://deepblue.lib.umich.edu/bitstream/2027.42/57144/1/OP708.pd

    Introduction

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75737/1/j.1095-8312.1986.tb01745.x.pd

    New species of Rattus

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    32 p. : ill., maps ; 26 cm.Includes bibliographical references (p. 30-32)."A new species, Rattus tawitawiensis, is described from Tawitawi Island in the southern Sulu Islands. It is native to the island, whereas Rattus rattus mindanensis, which also occurs there, is not. The known mammalian fauna of the Sulu Archipelago has characteristics indicating that the islands have had no recent land-bridge connection to either Borneo or Mindanao; this is consistent with geological evidence. The new species has no close relative now living in either the Philippine Islands to the east or on the islands and peninsula of the Sunda Shelf to the west. In morphology, the Tawitawi rat is most similar to species of Rattus living on islands rimming the Sunda Shelf beyond the 180 m bathymetric line. These peripheral isolates appear to be most similar to Rattus tiomanicaus among the extant fauna of the Sunda Shelf"--P. [1]

    Relationships of pocket gophers of the genus Geomys from the Central and Northern Great Plains

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    Three species of pocket gophers of the genus Geomys exist in the Great Plains north of Texas. The northernmost of these, G. bursarius, consists of the widespread, variable nominate subspecies and two more restricted, less variable subspecies (G. b. illinoensis and G. b. wisconsinensis). The second species, from the central plains, G. lutescens, has two subspecies within the study area (G. l. lutescens and G. l. major), and one or more extralimital subspecies. The third species, G. breviceps, is represented in the southern plains (in Oklahoma) by G. b. sagittalis, and by several subspecies outside of our study area. All species are distinguishable on the basis of cranial morphology, karyology, and ectoparasite fauna, and show minor differences in bacula. All specimens previously thought to be intergrades between the three species were reexamined and found to be clearly assignable to one species or the other, with no evidence of intergradation. Hybridization between G. bursarius and G. lutescens occurs only at a single locality in Nebraska, and introgression there is inconsequential. Hybridization between G. lutescens and G. breviceps probably occurs in several places in east-central Oklahoma, but the hybrid zones are narrow, and gene flow appears to be restricted. Variation within all species is mostly clinal; non-clinal variation is thought to be due to the late-Pleistocene history of the gophers. Analysis of cranial and other characters indicates that G. bursarius and G. lutescens are recently derived from a stock similar to G. breviceps and G. personatus. Geomys pinctis had the most primitive features of the species considered, and was probably separated from the others at an early date

    Tarsomys and Limnomys

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    138 p. : ill., maps ; 26 cm.Includes bibliographical references (p. 135-138)."Species of Tarsomys and Limnomys are found only on the island of Mindanao in the Philippine Archipelago. Both genera were named by Mearns in 1905 but never adequately diagnosed or described, a situation we rectify in this report. Tarsomys contains the type species, T. apoensis, which has been collected only from tropical lower and upper montane rain forest between 5200 and 7500 ft, and a new species, T. echinatus, known by a sample from tropical lowland evergreen rain forest between 2700 and 3700 ft. Limnomys is monotypic and the species L. sibuanus is represented by only five examples obtained from tropical montane rain forest between 6200-7200 and 9000 ft. Among Philippine murines, the phylogenetic alliances of Tarsomys and Limnomys are with species of Tryphomys, Abditomys, Bullimus, and Rattus. These genera form one of three groups which reflect the broad outlines of a pattern of phylogenetic relationships estimated by us from a preliminary survey of primitive and derived character states among samples of native Philippine murine rodents, based primarily on study skins and skulls. Another group contains the species of Phloeomys, Crateromys, Carpomys, Batomys, Apomys, Crunomys, Archboldomys, Chrotomys, Celaenomys, and Rhynchomys. The final group holds only Anonymomys mindorensis. The relationships of Tarsomys and Limnomys to members within their group are unresolvable within the context of our study"--P. 3

    Report on a Survey of Mammals of the Sierra Madre Range, Luzon Island, Philippines

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    An inventory of mammals was undertaken at 11 localities along the Sierra Madre range in 2002 to 2005, in areas where few or no data were available previously.  The inventory included lowland and montane forest habitats, at elevations from 300 to 1500 m.  Thirty-eight species of mammals were recorded, including nine new records for the mountain range.  One species, Kerivoula cf. papillosa, had not been recorded previously from the Philippines, and one, Coelops hirsutus, was known previously only from Mindanao and Mindoro Islands.  Two species, in the genera Apomys and Chrotomys, may represent previously unknown species.  We captured Archboldomys musseri only on Mt. Cetaceo, supporting previous evidence that it is endemic only to that mountain.A modified mist-netting technique (V-net) for insectivorous bats was effectively used to capture these species. The new records clearly demonstrate that the mammalian fauna of the Sierra Madre is poorly known.  Surveys of many additional areas are needed in all known habitat types along the Sierra Madre, especially karst, ultrabasic, and mossy forest, to fully document its diversity
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