Australian Biota Research Articles

The Study of The Varanus Komodoensis Venom

As a very ancient and mysterious species, Varanus komodoensis is the world's largest monitor lizard, the world's largest living lizard, and the last descendant of the Australian biota, his mystery makes scholars all over the world want to uncover its mysterious veil. This article studies exactly what he is most famous for, namely the authenticity of his venom and the way it hunts. This article examines the many aspects known about it, including its venom, its drool, and the truth about its hunting methods. And concluded that its method of hunting was relatively simple and crude, using its strong torso function to maximize the lethality of its strong jaw and strong tail, quickly stunning and killing its prey, instead of using what people used to think. To hunt with virus-filled saliva or venom-filled glands. The main purpose of this study is to provide a better understanding of what is Komodo dragon. To enrich its image in the eyes of the people. And to dispel some timeless misconceptions, that they are very mysterious and fascinating creatures, that deserve protection and numbers are not many that they need help even more.

A new Eocene species of presbyornithid (Aves, Anseriformes) from Murgon, Australia

The taxa found in an Eocene deposit, near Murgon, Queensland, the only pre-Oligocene Paleogene site recording a terrestrial vertebrate fauna from Australia, are very significant for the insight they provide concerning the evolution of the Australian biota. Here we resolve the identity of fossils previously referred to the Graculavidae, waterbirds of then unresolved affinities. We taxonomically describe the first bird to be named from this fauna, Murgonornis archeri gen. et sp. nov., Presbyornithidae. Our findings reveal that presbyornithids were widespread globally in the earliest Eocene, and that this family had a history on Australia from at least 55 Ma until ca. 24 Ma, when they disappear from the fossil record.Trevor H. Worthy [trevor.worthy@flinders.edu.au], College of Science and Engineering, Flinders University, GPO Box 2100, Adelaide 5001, SA, Australia; Vanesa L. De Pietri [vanesa.depietri@canterbury.ac.nz], University of Canterbury, School of Earth and Environment, Private Bag 4800, Christchurch 8140, New Zealand; R. Paul Scofield [pscofield@canterburymuseum.com], Canterbury Museum, 11 Rolleston Avenue, Christchurch 8013, New Zealand; Suzanne J. Hand [s.hand@unsw.edu.au], Earth and Sustainability Science Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia.

A new look at an old Australian raptor places Taphaetus lacertosus de Vis 1905 in the Old World vultures (Accipitridae: Aegypiinae).

The Australian Pleistocene fossil record of the Accipitridae (hawks, eagles and Old World vultures) is sparse and poorly known. Only two extinct confirmed accipitrid species have been described for this time period; both have received little investigation since their description. One is Taphaetus lacertosus de Vis, 1905, described from a distal humerus and a quadrate from north-eastern South Australia. While this species was verified as an accipitrid in subsequent studies, its more precise taxonomic affinities have remained conjectural. In this study, a new analysis incorporating newly referred material and phylogenetic analyses using a wide range of accipitriforms reveals that the lectotype humerus of T. lacertosus is an Old World vulture in the subfamily Aegypiinae. The associated quadrate, one of two original syntypes from which de Vis named this species, is of an indeterminate species of ardeid. We erect the novel genus Cryptogyps, to accommodate the species lacertosus, as it cannot be placed in Taphaetus de Vis, 1891, because the type species of this genus, Uroaetus brachialis de Vis, 1889, was transferred back to the genus Uroaetus, a synonym of Aquila Brisson, by de Vis in 1905. Further, U. brachialis is now considered a synonym of Aquila audax (Latham, 1801). Moreover, Taphaetus de Vis, 1891 is a senior homonym of Taphaetus de Vis, 1905, type species Taphaetus lacertosus de Vis, 1905, making the 1905 version of the genus unavailable. Newly referred fossils from Wellington Caves (NSW) and the Nullarbor Plains (WA) reveal this taxon had a wide geographical range across Pleistocene Australia. The referred tarsometatarsus lacks hyper-developed trochleae, indicating that Cryptogyps lacertosus (de Vis, 1905) comb. nov., was probably a scavenger like other aegypiines. Identification of Cryptogyps lacertosus as an aegypiine significantly expands the palaeogeographical range of the Old World vultures, hitherto unknown in Australia. The avian guild of large, obligate scavenging birds of prey, is currently absent in the modern Australian biota, but its former presence is not surprising given the megafauna-rich communities of the Pleistocene.

A glide over the Indo-Australian geological maze: repeated transgressions of Lydekker’s and Wallace’s Lines in archdukes, barons and dukes (Nymphalidae: Limenitidinae: Adoliadini)

Abstract Archdukes, barons, counts, dukes and marquises are forest-dwelling butterflies found in mainland Asia and most islands of the Indo-Australian archipelago west of Wallace’s Line, with only a few species occurring as far east as the Bismarck Archipelago. This pattern is unusual among butterfly groups of the region, which often present more widespread geographical ranges bearing little signature of Lydekker’s and Wallace’s Lines. Using a molecular multimarker matrix, we infer the first dated phylogeny for this clade and estimate its biogeographical history. We recover the Oriental genus Euthalia as polyphyletic, although other genera are monophyletic. The clade originated in continental Indomalaya in the late Oligocene ~24 Mya, when the Indo-Australian archipelago was at one of the most dynamic stages of its orogeny. Multiple independent colonization events towards the Lesser Sunda Islands, Moluccas, Australia and New Guinea suggest the relative permeability of Lydekker’s and Wallace’s Lines to these butterflies. Colonization of Melanesia took place twice, probably before the recent formation of Sulawesi. The study of Indo-Australian Adoliadini provides additional evidence that biogeographical barriers long thought to prevent exchange between the Asian and Australian biotas are, in fact, permeable especially to vagile insect lineages in the region.

Possible windborne transmission of giant willow aphid Tuberolachnus salignus (Gmelin) (Hemiptera: Aphididae: Lachninae) westward from New Zealand to Australia

ABSTRACTThe first records of Tuberolachnus salignus (Gmelin), the giant willow aphid, were reported from New Zealand and Australia in December 2013 and March 2014 respectively. The host plants are various members of Salix and Populus. The pathway used by the aphid to enter Australasia remains unknown, but natural aerial dispersal across the Tasman Sea is proposed to explain its first appearance within 3 months in Australia and New Zealand. Previous examples of aphids crossing the Tasman Sea are summarised. Windborne transmission due to the predominantly westerly winds from Australia to New Zealand is more likely based on past experience. However, we demonstrate using the HYSPLIT air trajectory model that it is possible that the aphid was carried on a reverse trajectory from New Zealand to southern Tasmania. Without more regular and systematic surveillance of New Zealand and Australian insect biota, it will continue to be difficult to ascertain the timing, origin and dispersal pathways of introduced insects.

Does extreme flooding drive vegetation and faunal composition across the Gulf Plains of north‐eastern Australia?

AbstractHigh levels of sub‐speciation in Australian mesic zone taxa have been attributed to the creation of biogeographic barriers by Pleistocene expansion of the arid zone. However, several of these barriers also align with major floodplains. The Carpentarian Barrier in the Gulf Plains (GUP) – one of Australia's most significant biogeographic barriers – experiences extreme floods on a sub‐decadal timescale. These floods rise suddenly, cover thousands of square kilometres to a depth of several metres and can take weeks to subside. We investigated whether these floods have shaped community composition. If this is the case, species that are particularly vulnerable to extreme flooding – understorey animals and woody plants, particularly shrubs – should be under‐represented, and grasslands should be over‐represented on GUP floodplains. We used Akaike selection of logistic models to assess influence of floodplains and other potential drivers on grassland distribution and shrub abundance, and on representation of understorey fauna. We also compared post‐flood faunal records with the bioregional data set to assess influence of the 2009 flood on representation of understorey reptiles. Grasslands and shrub‐free vegetation were significantly over‐represented and understorey fauna significantly under‐represented on floodplains, even when the influences of other factors were taken into account. Understorey Gekkota were absent from – and understorey skinks under‐represented in – recently flooded areas. Hence, floods appear to have shaped community composition on GUP floodplains by selectively displacing and/or destroying woody plants – particularly shrubs – and understorey animals. Our findings demonstrate association rather than causality, but show that further examination of the ecological and biogeographic impacts of extreme flooding is warranted. Influence of floods on the Australian biota should be considered an ongoing ecological and evolutionary driver, and one that is likely to intensify as extreme floods are expected to become more frequent under climate change.

Historical reconstruction unveils the risk of mass mortality and ecosystem collapse during pancontinental megadrought

An important new hypothesis in landscape ecology is that extreme, decade-scale megadroughts can be potent drivers of rapid, macroscale ecosystem degradation and collapse. If true, an increase in such events under climate change could have devastating consequences for global biodiversity. However, because few megadroughts have occurred in the modern ecological era, the taxonomic breadth, trophic depth, and geographic pattern of these impacts remain unknown. Here we use ecohistorical techniques to quantify the impact of a record, pancontinental megadrought period (1891 to 1903 CE) on the Australian biota. We show that during this event mortality and severe stress was recorded in >45 bird, mammal, fish, reptile, and plant families in arid, semiarid, dry temperate, and Mediterranean ecosystems over at least 2.8 million km2 (36%) of the Australian continent. Trophic analysis reveals a bottom-up pattern of mortality concentrated in primary producer, herbivore, and omnivore guilds. Spatial and temporal reconstruction of premortality rainfall shows that mass mortality and synchronous ecosystem-wide collapse emerged in multiple geographic hotspots after 2 to 4 y of severe (>40%) and intensifying rainfall deficits. However, the presence of hyperabundant herbivores significantly increased the sensitivity of ecosystems to overgrazing-induced meltdown and permanent ecosystem change. The unprecedented taxonomic breadth and spatial scale of these impacts demonstrate that continental-scale megadroughts pose a major future threat to global biodiversity, especially in ecosystems affected by intensive agricultural use, trophic simplification, and invasive species.

Biocontrol in Australia: Can a carp herpesvirus (CyHV-3) deliver safe and effective ecological restoration?

The Australian Government is considering Cyprinid herpesvirus 3 (CyHV-3) for biocontrol of invasive common carp (Cyprinus carpio L.). We review the evidence-base for its potential ecological risks, benefits and effectiveness. Lower carp abundance may boost native fish biomass and improve water clarity, but there is little evidence available to suggest that the virus, alone or used in combination with other methods, can deliver effective or safe biocontrol. Further, the virus may already be present in Australia. Overseas, the virus has caused sporadic and localized mortalities of carp in lakes and rivers, but has generally had no long-term measurable effect on wild carp or native fish populations. The temperature range of disease (18–28 °C), unknown co-factors causing outbreaks, and predictable re-colonization and recruitment boom of immune and virus-resistant carp, following a biocontrol release, remain formidable and unmitigated barriers to success. CyHV-3 infection trials on Australian biota have unexplained high mortality rates of recreationally-important and threatened fishes, and the role of asymptomatic carriers remains uncertain. Finally, Australia has national and international obligations to ensure that there are no perverse outcomes from biocontrol actions. Despite political pressure, there is no environmental justification to rush the release of this virus. To achieve the Government goals of restoring native biodiversity we advocate that key uncertainties, risks and efficacy barriers first need to be addressed. It is only then that viral biocontrol could be considered a viable tool to complement broader ecological restoration strategies for Australia’s waterways.

Biological responses to the press and pulse of climate trends and extreme events

The interaction of gradual climate trends and extreme weather events since the turn of the century has triggered complex and, in some cases, catastrophic ecological responses around the world. We illustrate this using Australian examples within a press–pulse framework. Despite the Australian biota being adapted to high natural climate variability, recent combinations of climatic presses and pulses have led to population collapses, loss of relictual communities and shifts into novel ecosystems. These changes have been sudden and unpredictable, and may represent permanent transitions to new ecosystem states without adaptive management interventions. The press–pulse framework helps illuminate biological responses to climate change, grounds debate about suitable management interventions and highlights possible consequences of (non-) intervention.

New species of Acizzia (Hemiptera: Psyllidae) from an Australian endemic Solanum (Solanaceae)

AbstractAcizzia yeni sp. nov. is described from a single population on the Australian native plant, money‐leaf nightshade, Solanum nummularium S. Moore following its discovery during the 2009 ‘Bush Blitz’ survey of Lochada Reserve in semi‐arid Western Australia. The Australian Solanum‐feeding Acizzia now comprise four described species in a morphologically defined monophyletic group: Acizzia alternata Kent & Taylor, Acizzia credoensis Taylor & Kent, Acizzia solanicola Kent & Taylor and A. yeni sp. nov. The host range of these species is expanded from commercial and garden crops, e.g. eggplant, Solanum melongena L. and a weed, wild tobacco bush, Solanum mauritianum Scop., to include the Australian endemics flannel bush, Solanum lasiophyllum Dunal, Solanum nummularium and rock nightshade, Solanum petrophilum F. Muell. Notably, two of these species, A. credoensis and A. yeni sp. nov., were discovered, and the native host of another, A. solanicola, was identified as a direct result of Bush Blitz surveys in arid inland Australia, thereby establishing the Australian origin of the solanaceous‐feeding Acizzia. Further to updating our knowledge of the Australian biota, Bush Blitz surveys are here identified as a novel serendipitous means of providing targeted surveillance towards an increasingly economically important group of psyllids for pre‐emptive plant biosecurity.

Targeted capture to assess neutral genomic variation in the narrow-leaf hopbush across a continental biodiversity refugium

The Adelaide geosyncline, a mountainous region in central southern Australia, is purported to be an important continental refugium for Mediterranean and semi-arid Australian biota, yet few population genetic studies have been conducted to test this theory. Here, we focus on a plant species distributed widely throughout the region, the narrow-leaf hopbush, Dodonaea viscosa ssp. angustissima, and examine its genetic diversity and population structure. We used a hybrid-capture target enrichment technique to selectively sequence over 700 genes from 89 individuals across 17 sampling locations. We compared 815 single nucleotide polymorphisms among individuals and populations to investigate population genetic structure. Three distinct genetic clusters were identified; a Flinders/Gammon ranges cluster, an Eastern cluster, and a Kangaroo Island cluster. Higher genetic diversity was identified in the Flinders/Gammon Ranges cluster, indicating that this area is likely to have acted as a refugium during past climate oscillations. We discuss these findings and consider the historical range dynamics of these populations. We also provide methodological considerations for population genomics studies that aim to use novel genomic approaches (such as target capture methods) on non-model systems. The application of our findings to restoration of this species across the region are also considered.

Genome-Guided Discovery of Natural Products and Biosynthetic Pathways from Australia’s Untapped Microbial Megadiversity

Historically microbial natural product biosynthesis pathways were elucidated mainly by isotope labelled precursor directed feeding studies. Now the genetics underpinning the assembly of microbial natural products biosynthesis is so well understood that some pathways and their products can be predicted from DNA sequences alone. The association between microbial natural products and their biosynthesis gene clusters is now driving the field of ‘genetics guided natural product discovery’. This account overviews our research into cyanotoxin biosynthesis before the genome sequencing era through to some recent discoveries resulting from the mining of Australian biota for natural product biosynthesis pathways.

High-resolution, multiproxy palaeoenvironmental changes recorded from Two Mile Lake, southern Western Australia: implications for Ramsar-listed playa sites

Numerous saline playa lakes exist across the arid, semiarid and temperate regions of Australia. These playa lakes exhibit a diverse range of hydrological conditions to which the Australian aquatic invertebrate biota have become adapted and which the biota can utilise as refugia in times of hydrological deterioration. Saline playas also yield palaeoenvironmental records that can be used to infer lacustrine and catchment responses to environmental variability. We present a palaeoenvironmental record recovered from Two Mile Lake, a saline playa from southern Western Australia. Dating, based on quartz optical luminescence and 14C accelerator mass spectrometry of biogenic carbonates and organic fibres, suggests that most of the sediment was rapidly deposited at 4.36 ± 0.25 thousand years ago. Ostracods and non-marine foraminifera preserved in the sediment show periods of faunal colonisation of the lake with oscillations between hypersaline and oligosaline conditions. The geochemistry of ostracod valves and foraminifera tests suggests higher-frequency variability within the lake, and palynological changes indicate landscape changes, possibly in response to fire. The Two Mile Lake record highlights the utility of saline playas as archives of environmental change that can be used to guide wetland health management, particularly under the impacts of a changing climate.

Management of Biodiversity in Australia

The concept of holistic ecosystem research, termed community-physiology, has gradually developed over the last 150 years. The discipline of community-physiology investigates the physico-chemical processes that determine the structure, growth and biodiversity of plant communities (with associated consumers and decomposers), both above and below ground, in space and time, from the tropical north to the temperate south of Australia. These physico-chemical processes (aerodynamic fluxes — frictional, thermal, evaporative ± atmospheric salinity — plus available soil water and soil nutrients) need to be clearly enunciated and integrated in ‘ecosystem models’ in order to predict the effect of perturbations (such as Global Warming, nutrient pollution, invasive biota, fire, overgrazing, etc.) on Australian ecosystems. An increase in global temperatures of 2 o C is predicted to affect the development of the foliage covers of overstorey and understorey strata resulting in open-forests —> woodlands —> open-woodlands —> tall shrublands —> low shrublands throughout Australia. In order to conserve Australian biota for posterity, community-physiologists, ecosystem modelers and environmental impact ecologists must have a deep understanding of the eco-physiology of producers, consumers and decomposers that compose an ecosystem and how these organisms interact with the continually-changing physico-chemical processes in the atmosphere and soil, in space and time.

Australia's arid-adapted butcherbirds experienced range expansions during Pleistocene glacial maxima.

A model of range expansions during glacial maxima (GM) for cold-adapted species is generally accepted for the Northern Hemisphere. Given that GM in Australia largely resulted in the expansion of arid zones, rather than glaciation, it could be expected that arid-adapted species might have had expanded ranges at GM, as cold-adapted species did in the Northern Hemisphere. For Australian biota, however, it remains paradigmatic that arid-adapted species contracted to refugia at GM. Here we use multilocus data and ecological niche models (ENMs) to test alternative GM models for butcherbirds. ENMs, mtDNA and estimates of nuclear introgression and past population sizes support a model of GM expansion in the arid-tolerant Grey Butcherbird that resulted in secondary contact with its close relative--the savanna-inhabiting Silver-backed Butcherbird--whose contemporary distribution is widely separated. Together, these data reject the universal use of a GM contraction model for Australia's dry woodland and arid biota.

Remarkable uniformity in the densities of feral honey bee Apis mellifera Linnaeus, 1758 (Hymenoptera: Apidae) colonies in South Eastern Australia

AbstractIt is often assumed that the density of feral honey bee colonies in Australia is sufficient to provide adequate pollination services to the many agricultural crops that require pollination. In contrast, there is concern that the density of feral colonies is sufficiently high to have inimical effects on Australian biota. For both these reasons, it is desirable to have robust estimates of the density of feral honey bee colonies in Australian landscapes. In this study, we mated four to five queens with wild drones at disturbed and undisturbed sites in three of the major ecosystems in Victoria Australia and examined the paternities of worker offspring to estimate the density of feral colonies within mating range of the test queens. We show that the density of feral colonies differs little with land use (cleared or uncleared) and is similar across the state. Our data suggest that the density of feral colonies is probably insufficient to provide adequate pollination of agricultural crops and that neither land use nor local climate variation is a major factor determining density. Finally, our data suggest that the mating range sampled by test queens is significantly greater than previously assumed.

How Was the Australian Flora Assembled Over the Last 65 Million Years? A Molecular Phylogenetic Perspective

Australia has a mostly dry, open, fire-shaped landscape of sclerophyllous and xeromorphic flora dominated by eucalypt and acacia trees, with diverse shrubs from a few families such as Myrtaceae, Proteaceae, and Fabaceae. Using molecular phylogenies to test hypotheses derived from the fossil record, we review the principal forces that transformed the ancestral Gondwanan rainforest through the Cenozoic. Today's vegetation is a mix of ancient radiations that have persisted in Australia through dramatic climate change since before the breakup of Gondwana, and more recent lineages whose ancestors arrived by trans-oceanic dispersal. Signatures in the fossil record of lineage turnover and trait evolutionary change are detected in phylogenies, but often at earlier dates. The Australian biota is a sample of the wider region, with extinction of some taxa and radiation of others (due to chance and opportunity), but biotic and abiotic interactions have resulted in a unique flora and fauna.

Whose backyard? Some precautions in choosing recipient sites for assisted colonisation of Australian plants and animals

SummaryIn cases where assisted colonisation is the appropriate conservation tool, the selection of recipient sites is a major challenge. Here, we propose a framework for site selection that can be applied to the Australian biota, where planning for assisted colonisation is in its infancy. Characteristics that will be important drivers in the decision‐making process include the size of a recipient site, the potential to augment corridors and respond to niche gaps, the maximisation of climatic buffering, bioregional similarity, tenure security, and the minimisation of opportunities for hybridisation and invasiveness. Sites we suggest be precluded from assisted colonisation include sites of high species endemism, IUCN category 1 reference reserves and fully‐functioning threatened ecological communities.

Ivor Beatty: Publisher with a red pen.

PUBLISHERS have over time played enormous roles in the dissemination of written language and the communication of ideas through and between cultures. Too often they are dismissed as the rubber stamp on the title page or that part of the citations required in a bibliography. They are the least known yet most familiar names on a title page and for too many of us they are just an administrative necessity. The common image of the publisher is that of the business face and the practical production component of the publishing process. Compared to the author and the title of the book their names convey only broad categorical information to the readers. On joining the Pacific Conservation Biology, over ten years ago, I found that this stereotype was not true for Ivor Beatty. While he was all the things mentioned above he also entered into the publishing process with his red ink. His corrections to my manuscript were my first meeting with the man behind the name — he was the Beatty in Surrey Beatty & Sons. His corrections were a point of academic contention that I enjoyed with him; they were lesson well learnt. Many years before my first experience with Ivor’s red ink, on a lower rung of my educational ladder, I had chatted with Joe Forshaw about the disappearance of Australian publishers from the publishing of Australian biota. We could both recite a long list of names of well-known publishers who no longer published in Australia. The small market and prohibitive economic costs had pushed publishing off-shore. Australian science and its communication to Australians and the world were consequently suffering. The story is too familiar to repeat here and it occurs in many areas beyond publishing. However, Ivor Beatty continued publishing biological science in Australia. He provided the forum to get the message across the same forum that provides the authors a place to promote their ideas. Many of us have much to thank him for. It has been said that “It would be impossible to imagine any zoologist, botanist, ecologist or conservation biologist trained in Australia over the last 20 years who has not had their career influenced by contributions from Beatty’s publications” (Saunders et al. 2012). I concur: I cannot believe that any student or conservation biologist would not be citing from the extensive literature than has emanated from his publishing house. A search of any good university library would find many entries from Surrey Beatty & Sons under conservation headings and many with no comparable papers or chapters published elsewhere. As a student I benefited from this literature and as a professional academic my research continues to draw on publications that have moved through Ivor’s hands. While the authors and editors of the papers and chapters are ultimately responsible for the original ideas that are rarely or not published elsewhere, they would not have seen the light of day without Ivor’s hand. At the time of his passing I point to the litany of his publications from his lifetime of dedication to conservation biology and I celebrate his achievements and his life and I recall the publisher that corrected my manuscript with his red pen.

Bunnies, Bilbies, and the Ethic of Ecological Remembrance

Bunnies, Bilbies, and the Ethic of Ecological Remembrance