World's Mammals Research Articles

Evolutionary history and environmental variability structure contemporary tropical vertebrate communities

AbstractAimTropical regions harbour over half of the world's mammals and birds, but how their communities have assembled over evolutionary timescales remains unclear. To compare eco‐evolutionary assembly processes between tropical mammals and birds, we tested how hypotheses concerning niche conservatism, environmental stability, environmental heterogeneity and time‐for‐speciation relate to tropical vertebrate community phylogenetic and functional structure.LocationTropical rainforests worldwide.Time periodPresent.Major taxa studiedGround‐dwelling and ground‐visiting mammals and birds.MethodsWe used in situ observations of species identified from systematic camera trap sampling as realized communities from 15 protected tropical rainforests in four tropical regions worldwide. We quantified standardized phylogenetic and functional structure for each community and estimated the multi‐trait phylogenetic signal (PS) in ecological strategies for the four regional species pools of mammals and birds. Using linear regression models, we test three non‐mutually exclusive hypotheses by comparing the relative importance of colonization time, palaeo‐environmental changes in temperature and land cover since 3.3 Mya, contemporary seasonality in temperature and productivity and environmental heterogeneity for predicting community phylogenetic and functional structure.ResultsPhylogenetic and functional structure showed non‐significant yet varying tendencies towards clustering or dispersion in all communities. Mammals had stronger multi‐trait PS in ecological strategies than birds (mean PS: mammal = 0.62, bird = 0.43). Distinct dominant processes were identified for mammal and bird communities. For mammals, colonization time and elevation range significantly predicted phylogenetic clustering and functional dispersion tendencies respectively. For birds, elevation range and contemporary temperature seasonality significantly predicted phylogenetic and functional clustering tendencies, respectively, while habitat diversity significantly predicted functional dispersion tendencies.Main conclusionsOur results reveal different eco‐evolutionary assembly processes structuring contemporary tropical mammal and bird communities over evolutionary timescales that have shaped tropical diversity. Our study identified marked differences among taxonomic groups in the relative importance of historical colonization and sensitivity to environmental change.

Indicators to monitor the status of the tree of life.

Following the failure to fully achieve any of the 20 Aichi biodiversity targets, the future of biodiversity rests in the balance. The Convention on Biological Diversity's Kunming-Montreal Global Biodiversity Framework (GBF) presents the opportunity to preserve nature's contributions to people (NCPs) for current and future generations by conserving biodiversity and averting extinctions. There is a need to safeguard the tree of life-the unique and shared evolutionary history of life on Earth-to maintain the benefits it bestows into the future. Two indicators have been adopted within the GBF to monitor progress toward safeguarding the tree of life: the phylogenetic diversity (PD) indicator and the evolutionarily distinct and globally endangered (EDGE) index. We applied both to the world's mammals, birds, and cycads to show their utility at the global and national scale. The PD indicator can be used to monitor the overall conservation status of large parts of the evolutionary tree of life, a measure of biodiversity's capacity to maintain NCPs for future generations. The EDGE index is used to monitor the performance of efforts to conserve the most distinctive species. The risk to PD of birds, cycads, and mammals increased, and mammals exhibited the greatest relative increase in threatened PD over time. These trends appeared robust to the choice of extinction risk weighting. EDGE species had predominantly worsening extinction risk. A greater proportion of EDGE mammals (12%) had increased extinction risk compared with threatened mammals in general (7%). By strengthening commitments to safeguarding the tree of life, biodiversity loss can be reduced and thus nature's capacity to provide benefits to humanity now and in the future can be preserved.

Grazing regime effects on bird biodiversity overwhelmed by an interference competitor

The majority of the world's mammal biomass is domestic livestock. Intensive livestock grazing can negatively impact some elements of biodiversity. We quantified the effects of grazing management on bird occupancy over a 10-year period in patches of Australian endangered temperate woodland within paddocks subjected to one of three grazing regimes: continuous set stocking, rotational, and total livestock exclusion. Grazing may affect birds through altering resource availability, influencing vegetation structure, or affecting the occurrence of noisy miners (Manorina melanocephala), a native honeyeater that engages in interference competition with other birds.Using Bayesian generalized linear mixed models and multispecies occupancy modelling, we quantified relative and interactive effects on bird biodiversity of grazing, vegetation structure, and noisy miner occupancy. We found only muted grazing regime effects on woodland birds. However, many species responded to vegetation structure. Small invertivorous woodland birds responded positively to sapling abundance, and some (larger) species responded positively to the abundance of trees >50 cm. Furthermore, species richness increased with increased sapling abundance and trees >50 cm. The largest effects were associated with noisy miner occurrence, which drove reductions in small-bodied, invertivorous birds, effectively “swamping” the positive effects of vegetation attributes on these species.The profound impacts of noisy miners present challenges for bird conservation in woodland ecosystems, especially those subject to grazing. Management to reduce grazing pressure by domestic livestock may eventually help limit the impacts of the noisy miner, in part by facilitating natural regeneration of temperate woodlands to which small-bodied woodland birds respond positively.

Priorities for conserving the world’s terrestrial mammals based on over-the-horizon extinction risk

Three major axes of global change put the world's mammal biodiversity at risk: climate change, human population growth, and land-use change.1,2,3,4,5,6,7,8,9,10,11,12 In some parts of the world the full effects of these threats on species will only be felt in decades to come, yet conservation emphasizes species currently threatened with extinction, by threats that have already occurred. There have been calls for conservation to become more proactive by anticipating and protecting species that may not yet be threatened, but have a high chance of becoming threatened in the future.3,6,8,10,12,13,14 We refer to this as "over-the-horizon" extinction risk, and we identify such species among the world's nonmarine mammals by considering not only the severity of increase in threats faced by each species, but also the way each species' biology confers sensitivity or robustness to threats. We define four future risk factors based on species' biology and projected exposure to severe change in climate, human population, and land use. We regard species with two or more of these risk factors as especially vulnerable to future extinction risk.10,15,16,17,18,19 Our models predict that by 2100 up to 1,057 (20%) of nonmarine mammal species will have combinations of two or more future risk factors. These species will be particularly concentrated in two future risk hotspots in sub-Saharan Africa and southern/eastern Australia. Proactively targeting species with over-the-horizon extinction risk could help to future-proof global conservation planning and prevent a new wave of mammal species from becoming threatened with extinction by the end of this century.

Global protected areas seem insufficient to safeguard half of the world's mammals from human-induced extinction

Protected areas (PAs) are a cornerstone of global conservation and central to international plans to minimize global extinctions. During the coming century, global ecosystem destruction and fragmentation associated with increased human population and economic activity could make the long-term survival of most terrestrial vertebrates even more dependent on PAs. However, the capacity of the current global PA network to sustain species for the long term is unknown. Here, we explore this question for all nonvolant terrestrial mammals for which we found sufficient data, ∼4,000 species. We first estimate the potential population size of each such mammal species in each PA and then use three different criteria to estimate if solely the current global network of PAs might be sufficient for their long-term survival. Our analyses suggest that current PAs may fail to provide robust protection for about half the species analyzed, including most species currently listed as threatened with extinction and a third of species not currently listed as threatened. Hundreds of mammal species appear to have no viable protected populations. Underprotected species were found across all body sizes, taxonomic groups, and geographic regions. Large-bodied mammals, endemic species, and those in high-biodiversity tropical regions were particularly poorly protected by existing PAs. As new international biodiversity targets are formulated, our results suggest that the global network of PAs must be greatly expanded and most importantly that PAs must be located in diverse regions that encompass species not currently protected and must be large enough to ensure that protected species can persist for the long term.

On the Qualitative Improvement of the Wildlife Protection Legislation

The Russian Federation is inhabited by about 150 thousand species of animals and this figure accounts for 9% of the world’s fauna. Guided by the logic of the utilitarian economic and legal approach called rational use of natural resources, this number includes a set of living organisms of all types of wild animals that permanently or temporarily inhabit the territory of the Russian Federation and are in a state of natural freedom, as well as related to the natural resources of the continental shelf and the exclusive economic zone of Russia, which are only part of the subject of the emerging complex branch of faunal law, together with wild animals in captivity, service animals, domestic animals, agricultural animals, and living organisms obtained as a result of the use of genetic engineering technologies. Higher mammals are sentient beings, that is, they are capable of experiencing suffering, pain, emotions, and the development of intelligence is confirmed by solving the most complex natural problems and puzzles, which allows us to consider them as individuals of non-human nature and non-human origin, and therefore it is incorrect to associate some of the objects of the animal world belonging to higher mammals with objects of property rights, that is, things. Commercial, amateur and sports hunting are types of hunting in Russia, carried out by trapping or shooting, expressed in the killing of hunting resources, that is, objects of the animal world that can be used for hunting. Hunting in the domestic legislation is a form of leisure, recreation and economic activity that ignores the natural rights of higher animals, including the right to life. A characteristic feature of the Law "On Responsible Treatment of Animals" is that its norms and principles for the treatment of animals do not apply to objects of the animal world, marine and aquatic mammals, animals classified as hunting resources, agricultural animals, living organisms created as a result of genetic engineering activities, which significantly reduces its humanistic significance.

Ultraconserved Elements Improve the Resolution of Difficult Nodes within the Rapid Radiation of Neotropical Sigmodontine Rodents (Cricetidae: Sigmodontinae).

Sigmodontine rodents (Cricetidae, Sigmodontinae) represent the second largest muroid subfamily and the most species-rich group of New World mammals, encompassing above 410 living species and ca. 87 genera. Even with advances on the clarification of sigmodontine phylogenetic relationships that have been made recently, the phylogenetic relationships among the 12 main groups of genera (i.e., tribes) remain poorly resolved, in particular among those forming the large clade Oryzomyalia. This pattern has been interpreted as consequence of a rapid radiation upon the group entrance into South America. Here, we attempted to resolve phylogenetic relationships within Sigmodontinae using target capture and high-throughput sequencing of ultraconserved elements (UCEs). We enriched and sequenced UCEs for 56 individuals and collected data from four already available genomes. Analyses of distinct data sets, based on the capture of 4634 loci, resulted in a highly resolved phylogeny consistent across different methods. Coalescent species-tree-based approaches, concatenated matrices, and Bayesian analyses recovered similar topologies that were congruent at the resolution of difficult nodes. We recovered good support for the intertribal relationships within Oryzomyalia; for instance, the tribe Oryzomyini appears as the sister taxa of the remaining oryzomyalid tribes. The estimates of divergence times agree with the results of previous studies. We inferred the crown age of the sigmodontine rodents at the end of the Middle Miocene, while the main lineages of Oryzomyalia appear to have radiated in a short interval during the Late Miocene. Thus, the collection of a genomic-scale data set with a wide taxonomic sampling provided resolution for the first time of the relationships among the main lineages of Sigmodontinae. We expect the phylogeny presented here will become the backbone for future systematic and evolutionary studies of the group.[Coalescent; Muroidea; Oryzomyalia; phylogenomics; polytomy; Rodentia; Sigmodontalia; species tree; UCEs.].

On the role of (and threat to) natural history museums in mammal conservation: an African small mammal perspective

The global environment is faced with growing threats from anthropogenic disturbance, propelling the Earth into a 6th mass extinction. For the world's mammals, this is reflected in the fact that 25% of species are threatened with some risk of extinction. During this time of species loss and environmental alteration, the world's natural history museums (NHMs) are uniquely poised to provide novel insight into many aspects of conservation. This review seeks to provide evidence of the importance of NHMs to mammal conservation, how arguments against continued collecting of physical voucher specimens is counterproductive to these efforts, and to identify additional threats to collecting with a particular focus on small mammals across Africa. NHMs contribute unique data for assessing mammal species conservation status through the International Union for Conservation of Nature's (IUCN) Red List of Threatened species. However, NHMs' contributions to mammal conservation go well beyond supporting the IUCN Red List, with studies addressing topics such as human impacts, climate change, genetic diversity, disease, physiology, and biodiversity education. Increasing and diverse challenges, both domestic and international, highlight the growing threats facing NHMs, especially in regards to the issue of lethally sampling individuals for the purpose of creating voucher specimens. Such arguments are counterproductive to conservation efforts and tend to reflect the moral opposition of individual researchers than a true threat to conservation. The need for continued collecting of holistic specimens of all taxa across space and time could not be more urgent, especially for underexplored biodiversity hotspots facing extreme threats such as the Afrotropics.

The world's highest-living mammal

The world's highest-living mammal

Evidence of zoonotic leprosy in Pará, Brazilian Amazon, and risks associated with human contact or consumption of armadillos.

Mycobacterium leprae (M. leprae) is a human pathogen and the causative agent for leprosy, a chronic disease characterized by lesions of the skin and peripheral nerve damage. Zoonotic transmission of M. leprae to humans by nine-banded armadillos (Dasypus novemcinctus) has been shown to occur in the southern United States, mainly in Texas, Louisiana, and Florida. Nine-banded armadillos are also common in South America, and residents living in some areas in Brazil hunt and kill armadillos as a dietary source of protein. This study examines the extent of M. leprae infection in wild armadillos and whether these New World mammals may be a natural reservoir for leprosy transmission in Brazil, similar to the situation in the southern states of the U.S. The presence of the M. leprae-specific repetitive sequence RLEP was detected by PCR amplification in purified DNA extracted from armadillo spleen and liver tissue samples. A positive RLEP signal was confirmed in 62% of the armadillos (10/16), indicating high rates of infection with M. leprae. Immunohistochemistry of sections of infected armadillo spleens revealed mycobacterial DNA and cell wall constituents in situ detected by SYBR Gold and auramine/rhodamine staining techniques, respectively. The M. leprae-specific antigen, phenolic glycolipid I (PGL-I) was detected in spleen sections using a rabbit polyclonal antibody specific for PGL-I. Anti-PGL-I titers were assessed by ELISA in sera from 146 inhabitants of Belterra, a hyperendemic city located in western Pará state in Brazil. A positive anti-PGL-I titer is a known biomarker for M. leprae infection in both humans and armadillos. Individuals who consumed armadillo meat most frequently (more than once per month) showed a significantly higher anti-PGL-I titer than those who did not eat or ate less frequently than once per month. Armadillos infected with M. leprae represent a potential environmental reservoir. Consequently, people who hunt, kill, or process or eat armadillo meat are at a higher risk for infection with M. leprae from these animals.

Declining populations in one of the last refuges for threatened mammal species in northern Australia

AbstractAustralia has contributed a disproportionate number of the world's mammal extinctions over the past 200 years, with the greatest loss of species occurring through the continent's southern and central arid regions. Many taxonomically and ecologically similar species are now undergoing widespread decline across the northern Australian mainland, possibly driven by predation by feral cats and changed fire regimes. Here, we report marked recent declines of native mammal species in one of Australia's few remaining areas that support an intact mammal assemblage, Melville Island, the largest island off the northern Australian coast. We have previously reported a marked decline on Melville Island of the threatened brush‐tailed rabbit‐rat (Conilurus penicillatus) over the period 2000–2015, linked to predation by feral cats. We now report a 62% reduction in small mammal trap‐success and a 36% reduction in site‐level species richness over this period. There was a decrease in trap‐success of 90% for the northern brown bandicoot (Isoodon macrourus), 64% for the brush‐tailed rabbit‐rat and 63% for the black‐footed tree‐rat (Mesembriomys gouldii), but no decline for the common brushtail possum (Trichosurus vulpecula). These results suggest that populations of native mammals on Melville Island are exhibiting similar patterns of decline to those recorded in Kakadu National Park two decades earlier, and across the northern Australian mainland more generally. Without the implementation of effective management actions, these species are likely to be lost from one of their last remaining strongholds, threatening to increase Australia's already disproportionate contribution to global mammal extinctions.

Bushmeat hunting and extinction risk to the world's mammals.

Terrestrial mammals are experiencing a massive collapse in their population sizes and geographical ranges around the world, but many of the drivers, patterns and consequences of this decline remain poorly understood. Here we provide an analysis showing that bushmeat hunting for mostly food and medicinal products is driving a global crisis whereby 301 terrestrial mammal species are threatened with extinction. Nearly all of these threatened species occur in developing countries where major coexisting threats include deforestation, agricultural expansion, human encroachment and competition with livestock. The unrelenting decline of mammals suggests many vital ecological and socio-economic services that these species provide will be lost, potentially changing ecosystems irrevocably. We discuss options and current obstacles to achieving effective conservation, alongside consequences of failure to stem such anthropogenic mammalian extirpation. We propose a multi-pronged conservation strategy to help save threatened mammals from immediate extinction and avoid a collapse of food security for hundreds of millions of people.

The rarest of them all

When Sam Turvey stared into the face of a Hainan gibbon he knew he had to join the effort to save the world's rarest mammal

Hidden in plain sight: Cryptic and endemic malaria parasites in North American white-tailed deer (Odocoileus virginianus).

Malaria parasites of the genus Plasmodium are diverse in mammal hosts, infecting five mammalian orders in the Old World, but were long considered absent from the diverse deer family (Cervidae) and from New World mammals. There was a description of a Plasmodium parasite infecting a single splenectomized white-tailed deer (WTD; Odocoileus virginianus) in 1967 but none have been reported since, which has proven a challenge to our understanding of malaria parasite biogeography. Using both microscopy and polymerase chain reaction, we screened a large sample of native and captive ungulate species from across the United States for malaria parasites. We found a surprisingly high prevalence (up to 25%) and extremely low parasitemia of Plasmodium parasites in WTD throughout the eastern United States. We did not detect infections in the other ungulate species nor in western WTD. We also isolated the parasites from the mosquito Anopheles punctipennis. Morphologically, the parasites resemble the parasite described in 1967, Plasmodium odocoilei. Our analysis of the cytochrome b gene revealed two divergent Plasmodium clades in WTD representative of species that likely diverged 2.3 to 6 million years ago, concurrent with the arrival of the WTD ancestor into North America across Beringia. Multigene phylogenetic analysis placed these clades within the larger malaria parasite clade. We document Plasmodium parasites to be common in WTD, endemic to the New World, and as the only known malaria parasites from deer (Cervidae). These findings reshape our knowledge of the phylogeography of the malaria parasites and suggest that other mammal taxa may harbor infection by endemic and occult malaria parasites.

Bats: a world of science and mystery

There are more than 1,300 species of bats - or almost a quarter of the world's mammal species. But before you shrink in fear from these furry of the night, consider the bat's fundamental role in our ecosystem. A single brown can eat several thousand insects in a night. Bats also pollinate and disperse the seeds for many of the plants we love, from bananas to mangoes and figs. Bats: A World of Science and Mystery presents these fascinating nocturnal creatures in a new light. Lush, full-color photographs portray bats in flight, feeding, and mating in views that show them in exceptional detail. The photos also take the reader into the roosts of bats, from caves and mines to the tents some bats build out of leaves. A comprehensive guide to what scientists know about the world of bats, the book begins with a look at bats' origins and evolution. The book goes on to address a host of questions related to flight, diet, habitat, reproduction, and social structure: Why do some bats live alone and others in large colonies? When do bats reproduce and care for their young? How has the ability to fly - unique among mammals - influenced bats' mating behavior? A chapter on biosonar, or echolocation, takes readers through the system of high-pitched calls bats emit to navigate and catch prey. More than half of the world's species are either in decline or already considered endangered, and the book concludes with suggestions for what we can do to protect these species for future generations to benefit from and enjoy. From the tiny bumblebee bat - the world's smallest mammal - to the Giant Golden-Crowned Flying Fox, whose wingspan exceeds five feet, A Battery of Bats presents a panoramic view of one of the world's most fascinating yet least-understood species.

Phylogenetic endemism in terrestrial mammals

AbstractAimPhylogenetic endemism (PE) identifies geographic concentrations of evolutionarily isolated and spatially restricted biota. Locations with high PE hold elements of biodiversity with little representation elsewhere and whose loss would impact disproportionately on phylogenetic diversity. We aim to determine the global distribution of PE for the world's mammals and to test hypotheses regarding the role of past and present environment and isolation in creating current patterns of evolutionary and spatial isolation.LocationGlobal land.MethodsIUCN range polygons were combined with a mammal supertree to estimate PE and related measures at three resolutions. We tested the relationship between PE and predictors representing current and Last Glacial Maximum (LGM) environment and isolation in a model selection framework, for all terrestrial mammals and separately for bats.ResultsWe identified 12 centres of mammal PE, with implications for conservation decisions. Endemism of mammal evolutionary diversity peaks predominantly in tropical and Southern Hemisphere island and montane regions. PE was most strongly associated with energy availability, isolation, elevation and low variability of current climate. Post LGM climate stability was a surprisingly weak predictor of PE compared with LGM climate itself. When controlling for current species ranges, PE is more strongly explained by past climate and past isolation.Main conclusionsWhile present conditions better explain species endemism, past climate and isolation are central to explaining PE. Isolation at the LGM was a significantly stronger predictor of PE than current isolation, confirming the key role of persistent barriers, even narrow ones such as Wallace's Line. This global evaluation of PE offers an innovative and effective way to capture and test the evolutionary underpinning of whole‐clade biogeography. With improving spatial and phylogenetic information, integrative measures such as PE offer a substantial contribution toward comprehending and conserving evolutionary diversity.

Priority Mammals for Biodiversity Conservation in Brazil

More than one fifth of the world's mammals are listed in an extinction risk category. However, extinction risk should not be the only criterion used in conservation prioritization schemes. Here, we used a species and spatial prioritization scheme for the conservation of Brazilian mammals that incorporates other parameters in addition to extinction risk. Our results suggest that 3.4% of all Brazilian mammal species are high priorities and 29.1% of all Brazilian ecoregions are also high priorities. Since 62.5% of the species identified as high-priority do not have any national conservation plan, we hope our results will help guide mammal conservation actions.

Metal accumulation in wild nine-banded armadillos

Nine-banded armadillos (Dasypus novemcinctus) are widespread and abundant New World mammals with a lifestyle that entails prolonged, intimate contact with soils. Thus, armadillos would seem a promising candidate as a sentinel species to monitor chemical contamination in terrestrial ecosystems. Surprisingly, there have been virtually no toxicology studies on armadillos. Here, we provide the first analysis of metal contaminants for wild armadillos. Liver tissues were obtained from 302 armadillos collected at 6 sites in Georgia and Florida, USA that varied in their extent of human disturbance, from rural pine plantations to highly modified military/space installations. Data were stratified by age (juvenile and adult), sex, and site. Temporal (yearly) variation was examined at two of the sites that were sampled over three consecutive years. Concentrations of aluminum, cadmium, copper, nickel, lead, and zinc were measured in liver samples from each site. Although reference levels are not available for armadillos, accumulated metal concentrations were comparable to those reported for other mammals. We found no evidence of sex or age differences in the concentrations of any metal, except for Cd (age) and Pb (sex and age). However, concentrations of most metals varied substantially across sites and over time. Finally, concentrations of many metals were positively correlated with one another, suggesting that they likely co-occurred in some areas. Collectively, this study indicates the utility of armadillos as a sentinel species for studies of metal contamination in terrestrial systems, and highlights the need for further studies of other toxicants in these animals.

The ecology of stress: a marriage of disciplines

The ecology of stress: a marriage of disciplines

The return of the living dead: unsettlement and the Tasmanian tiger

Australia has the ignominious distinction of having “lost” approximately half the world's mammals. Among these extinctions the Tasmanian tiger is perhaps the most iconic, not least because the “undead” thylacine has been routinely sighted since it passed into oblivion in the 1930s. I regard narratives of the “extinct” thylacine as a form of what Lacan called the “return of the real”, that is, a positionality between a symbolic death and an actual death. My methodology has been dictated as much by the elusiveness of my subject as by my own fascination with its discursive configuration. Following Steve Baker, I consider any understanding of the thylacine as being bound to its cultural representation; and as such I grant equal conceptual weight to accounts of the representational or the symbolic thylacine as I do to the “real” thylacine. Using published accounts of the colonial encounter with both the biophysical environment and the indigenous (Palawa) population, data drawn from an eclectic range of scientific and “natural history” texts as well as sources from popular culture, I argue that until the trauma of colonial abjection is reconciled (integrated into our historical memory) the undead will continue to return and haunt the Australian imaginary.