Academic literature on the topic 'Mammals melanesia'

Basic knowledge of species diversity and distributions underpins the study of island biogeography and is fundamental for conservation planning. In Solomon Islands, new mammals continue to be described and several lineages are yet to be documented from large islands where, presumably, they should occur. On Malaita and Makira, no giant rats (Solomys or Uromys), or monkey-faced bats (Pteralopex) have been documented by scientists, but traditional knowledge suggests they exist. In East Kwaio, Malaita, we combined traditional knowledge and scientific methods to survey mammals and search for these taxa. Camera traps, mist nets, spotlight surveys, echolocation call recorders, rat traps and active searches were used to produce an inventory of the island’s mammals. No Solomys, Uromys or Pteralopex were captured. However, detailed accounts suggest that giant rats and monkey-faced bats were present as recently as 1996 and 2002 respectively. Moreover, we consider the presence of gnawed Canarium nuts an indicator that giant rats still persist. The human population of Malaita is dense, hunting pressure appears high, feral cats are common, and logging is rapidly reducing primary forests. A notable feature of this work has been the commitment towards collaboration and upskilling landowners in mammal survey techniques. This collaboration has helped fuel a growing conservation movement on Malaita and led to the designation of three large conservation areas. Gathering evidence for the existence of undescribed mammals on Malaita is paramount for reducing further extinctions in Melanesia. Continued support for skilled community members in East Kwaio will be key to collecting this evidence.

Transposable elements (TEs), also known as jumping genes, are sequences able to move or copy themselves within a genome. As TEs move throughout genomes they often act as a source of genetic novelty, hence understanding TE evolution within lineages may help in understanding environmental adaptation. Studies into the TE content of lineages of mammals such as bats have uncovered horizontal transposon transfer (HTT) into these lineages, with squamates often also containing the same TEs. Despite the repeated finding of HTT into squamates, little comparative research has examined the evolution of TEs within squamates. Here we examine a diverse family of Australo–Melanesian snakes (Hydrophiinae) to examine if the previously identified, order-wide pattern of variable TE content and activity holds true on a smaller scale. Hydrophiinae diverged from Asian elapids ~30 Mya and have since rapidly diversified into six amphibious, ~60 marine and ~100 terrestrial species that fill a broad range of ecological niches. We find TE diversity and expansion differs between hydrophiines and their Asian relatives and identify multiple HTTs into Hydrophiinae, including three likely transferred into the ancestral hydrophiine from fish. These HTT events provide the first tangible evidence that Hydrophiinae reached Australia from Asia via a marine route.

Comprehensive morphology-based taxonomic revisions are presented for four mammal genera endemic to the Australo-Papuan region. These include Pseudohydromys Rummler, 1934 and Mallomys Thomas, 1898, small- and large-bodied rodent genera, respectively, endemic to montane areas on mainland New Guinea; the marsupial genus Spilocuscus Gray, 1862, distributed throughout lowland areas of mainland New Guinea, on most adjacent island groups, and in tropical northern Australia; and Pteralopex Thomas, 1888, a genus of large-bodied fruit-bats endemic to the Solomon and Fijian Archipelagos of outer Melanesia. Museum specimens of “moss-mice” traditionally classified in the genera Pseudohydromys, Microhydromys Tate and Archbold, 1941, Neohydromys Laurie, 1952, and Mayermys Laurie and Hill, 1954 are here referred to three generic-level lineages, Pseudohydromys (11 species), Microhydromys (one recognized species), and Mirzamys new genus (for two newly-described species). The 11 species of Pseudohydromys recognized here include six that are newly described. Much of this newly-characterized biological diversity is sympatric diversity. For example, samples attributed in the past to Pseudohydromys murinus Rummler, 1934 include two species, P. berniceae n. sp. and P. eleanorae n. sp., which have been collected syntopically with true P. murinus. Likewise, samples attributed in the past to Pseudohydromys occidentalis Tate, 1951 are also shown to represent a number of “cryptic” lineages sympatric with true P. occidentalis, including P. patriciae n. sp. and Mirzamys louiseae n. sp., as well as an additional overlooked allopatric taxon, Mirzamys norahae n. sp. Within Mallomys, the nature and extent of sympatric interactions between the giant-rats M. rothschildi Thomas, 1898, M. aroaensis (De Vis, 1907), and M. istapantap Flannery, Aplin, and Groves, 1989 are reviewed and clarified. Subspecific boundaries within M. rothschildi are re-assessed, and in total seven species of Mallomys are recognized, including M. hercules Thomas, 1912, an allospecies endemic to the outlying mountain ranges of the Huon Peninsula, and two newly-described species from other outlying mountain blocks (the Arfak Mountains of western New Guinea and Mt. Bosavi in south-central New Guinea). The spotted cuscuses, genus Spilocuscus, are difficult to classify at species-level because most taxa in the genus are distributed allopatrically or parapatrically. A minimum of seven geographic “morphs” can be recognized in the genus on the basis of size and pelage characters. The oldest name in the genus, S. maculatus, is shown to refer to dark-spotted cuscuses from the Moluccas and southern New Guinea, not to the orange and white cuscuses from northern New Guinea, as traditionally applied. A review of craniometric and qualitative morphological traits confirms that each of these “morphs” (as delineated by external morphology) is characterized by other distinctive morphological attributes; this fact and the lack of evidence for introgression between any of these various taxa is used to argue that most of these seven morphologically-distinctive lineages should be recognized as distinct allospecies. Only two taxa in the genus co-occur sympatrically—the large-bodied, black-saddled/spotted taxon S. rufoniger and a smaller, orange and white species, both of which are shown to be widely distributed in both northern and western New Guinea. No scientific name is available for the latter taxon, which is newly designated as Spilocuscus tardus n. sp. Taxa traditionally classified in Pteralopex are referred here to two distinct genera, Pteralopex, comprising only those species endemic to the Solomon Archipelago, and Mirimiri Helgen, 2005, for the monotypic Fijian representative M. acrodonta (Hill and Beckon, 1978). Five species of Pteralopex are recognized in total. Museum specimens traditionally identified as “Pteralopex anceps” are shown to represent two sympatric species, P. anceps Andersen, 1909 and P. flanneryi Helgen, 2005 (the largest species in the genus), both of which are endemic to islands in the north-eastern Solomon Islands that were once part of a larger Pleistocene landmass; insular co-occurrence of P. atrata Thomas, 1888 and the recently-described P. taki Parnaby, 2002 on New Georgia is also newly documented. Each of these revisions highlights sympatric interactions and substantial undiagnosed biological diversity overlooked by previous reviewers, and illuminates intraregional biogeographic boundaries more accurately as a result. Before I began this study four years ago, a total of 17 mammal species were formally recognized within the genera Pseudohydromys, Neohydromys, Mayermys, Microhydromys, Mallomys, Spilocuscus, and Pteralopex (Flannery 1995a, 1995b). This thesis defends the recognition of 33 species within those same generic lineages, which suggests that the magnitude of biological diversity across the Melanesian mammal fauna could well be underestimated by fully one-half. Preliminary results reflecting complementary discoveries of overlooked sympatric diversity in other Melanesian mammal genera (Uromys, Microperoryctes, Myoictis, Pteropus, Nyctimene, Leptomys, and others) are also briefly discussed. Similar comprehensive reviews, analysing morphometric attributes and qualitative anatomical characters of all available museum specimens, are still needed for all remaining Melanesian mammal genera before any reasonable holistic portrayal of community ecology and historical biogeography can be developed for the Melanesian mammal fauna as a whole.
Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2007