A reassessment of the type locality of the giant rat Solomys salamonis (Rodentia:Muridae) from the Solomon Islands

The Solomon Islands support a diverse and highly endemic rodent fauna. Most species are poorly known and rarely encountered. Solomys salamonis is one such endemic species known only from the holotype collected in 1881. The type locality for the species has been repeatedly confused in the literature, and this uncertainty has hampered attempts to evaluate the status of the species. I reassessed the type locality based on review of the published literature and records and archives of the Australian Museum, Sydney. My review indicates that the type locality is Ugi Island, not Florida Island as widely reported in the recent literature. A subsequent, preliminary survey on Ugi Island failed to confirm the presence of the species; however, the occurrence of some original forest on Ugi Island encourages further detailed surveys to determine whether S. salamonis is still extant

A new species of giant rat (Muridae, Uromys) from Vangunu, Solomon Islands

We describe the first new rodent species from Solomon Islands in more than 80 years. This new giant rat is known from a single specimen captured in a commercially felled Dillenia salomonensis tree on Vangunu Island. Morphologically, it closely resembles a fascinating secondary radiation of 3 species of Uromys (Cyromys) that are endemic to Guadalcanal Island. The cranium can be readily distinguished from those of other species of Uromys by its shorter maxillary tooth row, and shorter incisive foramina. The existence of this species has been suspected for over 2 decades. It is rare and cryptic, and conservation status is Critically Endangered due to its small distributional range, apparent low population densities, and rapid progress of commercial logging on Vangunu Island. Further surveys to locate additional animals and support for community led conservation initiatives on Vangunu are urgently needed to safeguard the species

Buying through your teeth: traditional currency and conservation of flying foxes Pteropus spp. in Solomon Islands

Globally, island bats are vulnerable to subsistence hunting, with widespread population declines, local extirpations and extinctions. Bats are important to the ecological functioning of remote oceanic islands, and thus the sustainable management of hunting of flying foxes Pteropus spp. is a conservation priority in the Pacific. In Solomon Islands people hunt flying foxes for bushmeat and their canine teeth, which are used as traditional currency. The value of teeth potentially increases hunting pressure on species of Pteropus. We interviewed 197 people on Makira Island to determine the nature of this use and how it may influence flying-fox populations. We asked questions to gather information about hunting practices, the value of canine teeth, utilization of traditional currency, and population trends of Pteropus. Flying-fox teeth remain highly valued on Makira. It is primarily the teeth of P. tonganus that are used rather than those of the smaller P. cognatus. Although flying foxes are not targeted solely for their teeth, this added value seemingly drives hunters to focus on P. tonganus. Hunting varied across five regions of Makira and high hunting pressure corresponded with perceived rarity of P. tonganus. Regions with low hunting pressure may be opportune locations to initiate flying-fox conservation on Makira

Tailoring release protocols to individual species and sites: one size does not fit all

Reintroduction programs for threatened species often include elaborate release strategies designed to improve success, but their advantages are rarely tested scientifically. We used a set of four experiments to demonstrate that the influence of release strategies on short-term reintroduction outcomes is related to both intrinsic and extrinsic factors. We compared different reintroduction strategies for three mammal species in an arid environment where exotic mammalian predators were removed. Wild greater stick-nest rats selected vegetation shelter sites with greater structural density than captive-bred rats, travelled further from the release site and experienced lower rates of mortality. In comparison, there was no difference in mortality or movement between wild and captive-bred greater bilbies. Burrowing bettongs and greater bilbies were also subjected to immediate and delayed release strategies and whilst no difference was detected in bilbies, bettongs that were subjected to delayed releases lost less weight and took less time to establish burrows than those that were immediately released. Interspecific differences in treatment response were attributed to predation risk, the nature of the release site, and behavioural traits such as shelter investment and sociality. Our varied results highlight the inadequacies of review articles focusing on optimum release protocols due to their attempt to generalise across species and release sites. We provide an example of a predictive model to guide future release strategy experimentation that recognises the range of intrinsic and extrinsic factors influencing reintroduction outcomes. We encourage researchers to treat programs experimentally, identify individual site and species characters that may influence release strategies and record data on movements, mortality, weight dynamics, and settling times and distances. The inherent issues of small sample size and low statistical power that plague most reintroduction experiments suggests there is also a need for increased standardisation and publication of data sets to enable appropriate meta-analyses to occur

Going the distance on kangaroos and water: A review and test of artificial water point closures in Australia

Grazing by overabundant herbivores can cause land degradation and reduce biological diversity. Across arid and semi-arid Australia, predator control, pasture improvement, and artificial water points (AWP) have contributed to increased populations of kangaroos and wallaroos (Macropus spp.). Control efforts (e.g. culling, predator reintroduction, fertility control) can be expensive, controversial and/or unsustainable in the long term. Closure of AWP is an alternative. We reviewed closures in Australia and found experimental tests have been few, and results unconvincing for two main reasons. Firstly, no study has tested AWP closures over distances influential to kangaroos. We identified seven AWP closure experiments in Australia. Five did not generate areas beyond 5 km from water and two used a method ineffective for excluding kangaroos. Secondly, post-closure monitoring has frequently been too short to detect changes amongst natural environmental fluctuations. Our own experimental AWP closure did not influence kangaroo populations and reaffirmed that kangaroo densities are dictated by food availability in Australia's water rich rangelands. Larger experiments are needed with systematic AWP closures that generate water remote landscapes, preferably exceeding 10 km from water. Monitoring must span dry, hot periods of below average rainfall when kangaroos are most likely dependent on drinking water

Terrestrial vertebrate richness of the inhabited Torres Strait Islands, Australia

Located between New Guinea and Australia, Torres Strait and its islands provide an opportunity to examine the results of recent isolation on the Australo-Papuan fauna. However, records of the modern diversity of terrestrial vertebrates on the islands remained scattered and poorly documented. Analyses of terrestrial vertebrate inventories and physical island variables can provide insight into pre-existing conditions of the Sahul land bridge and useful strategies for conservation efforts. We collated all available records of terrestrial vertebrates from the 17 inhabited islands and supplemented these with our own systematic surveys. We used Spearman’s rank correlation coefficient and nested analysis to determine how species richness relates to physical island variables. We also used cluster analysis to group similar islands based on their vertebrate assemblages. Vertebrate richness is not correlated with Simpson’s habitat diversity but is correlated with total number of habitat types, indicating that rare habitats may contribute disproportionately to richness. The archipelago supports a depauperate Australo-Papuan fauna and the assemblages found on smaller islands are subsets of those on larger islands. Island size is the most effective predictor of species richness, and the analysis reveals that geographically related islands support similar suites of species. The frequency with which our surveys added new records to individual island inventories highlights the need for additional sampling in the region

Ecological generalism and resilience of tropical island mammals to logging: a 23 year test

Tropical forest disturbance is a key driver of global biodiversity decline. On continents, the effects of logging are greatest on endemic species, presumably because disturbance is more likely to cover narrower distributions (the "cookie cutter" model). Islands hold disproportionate biodiversity, and are subject to accelerating biotic homogenization, where specialist endemics are lost while generalists persist. We tested responses of tropical island mammals to logging at multiple spatial scales, using a long-term experimental test in a Pacific archipelago. The most widely distributed ecological generalists did not decline after logging, and we detected no overall changes in relative abundance or species diversity. However, endemics with small ranges did decline in response to logging. The least mobile and most range-restricted species declined even at the smallest spatial scale, supporting the cookie cutter model for sedentary species, and suggesting that habitat change due to selective logging is contributing to biotic homogenization on islands

White-footed dunnarts (Sminthopsis leucopus) in Queensland’s Wet Tropics, with the description of a new subspecies

A population of white-footed dunnarts (Sminthopsis leucopus) occurs in the Wet Tropics bioregion of tropical north Queensland, Australia separated by about 1800 km from conspecifics in temperate New South Wales, Victoria and Tasmania. We conducted targeted surveys for S. leucopus in north-east Queensland and obtained new records, including the first reported capture of the species in Queensland in 18 years. We assessed the genetic and morphological divergence of the north Queensland population against New South Wales, Victorian and Tasmanian S. leucopus, in conjunction with distribution and habitat differences, to assess whether this isolate should be described as a distinct taxon. Sequencing of the mitochondrial Cytochrome b gene revealed genetic divergence estimates of 2.3–2.8% and 4.3–4.8% between the north Queensland population and S. l. ferruginifrons (Victoria) and S. l. leucopus (Tasmania) respectively. Based on genetic divergence, cranial morphology, differences in habitat, and geographical isolation, we describe the north Queensland population as a new subspecies of Sminthopsis leucopus. We suggest a conservation classification of Endangered given its small distribution, apparent low density, tropical upland location and potential threats, especially related to climate change

The mammals of northern Melanesia: speciation, ecology, and biogeography

1. Analyses of the distributions of northern Melanesia's avifauna have helped researchers formulate major theories of evolution, speciation, and biogeography. In comparison, the region's mammalian fauna has been the subject of few empirical analyses of biogeography. Knowledge of mammalian biogeography is needed to formulate sound conservation strategies for mammals in the region and will help further advance these theories