Toxic tucker: the potential impact of Cane Toads on Australian reptiles

2006 ◽  
Vol 12 (1) ◽  
pp. 40 ◽  
Author(s):  
James G. Smith ◽  
Ben L. Phillips

Cane Toads Bufo marinus are a highly successful invasive species, having invaded more than twenty countries in the last 150 years. In Australia, they currently occupy more than 1 million square kilometres. Toads are highly toxic and Australian predators have no evolutionary history with the cardiac toxins in toad skin. As such, toads constitute a novel and extremely toxic prey for Australia's predators. Australia's reptiles are perhaps the largest group likely to be affected by the invasion of the toad. By examining species distributions, we conclude that 59% of agamids, 85% of the varanids and all of Australia's crocodiles and freshwater turtles are potentially at risk from toads. We then assayed eleven species of reptile; one freshwater turtle (Chelidae), two crocodiles (Crocodylidae), two dragons (Agamidae), one python (Pythonidae) and five species of monitor (Varanidae) for resistance to toad toxin. We found a high level of variation between species in resistance to toad toxin but in all cases (except for one species of crocodile) all species were easily capable of eating a toad large enough to kill them. We conclude that toads pose a real and ongoing threat to the majority of Australian reptile species we examined.

2012 ◽  
Vol 12 (3) ◽  
pp. 35-49 ◽  
Author(s):  
Bernadete Maria de Sousa ◽  
Samuel Campos Gomides ◽  
Alexandre de Assis Hudson ◽  
Leonardo Barros Ribeiro ◽  
Iara Alves Novelli

The Atlantic Forest of the state of Minas Gerais, as well as the remnants of this domain in the rest of Brazil, suffers a marked reduction in size and anthropogenic alteration. This habitat degradation is directly reflected in the decrease of species richness within these natural environments. In this sense, the inventory of extant species is necessary to understand the species composition of regions under threat. Despite the great richness of existing reptile species in Minas Gerais, the level of knowledge about the fauna in this state is considered unsatisfactory and very fragmented. The aim of this study was to record the composition of the reptile fauna of the municipality of Juiz de Fora through the revision of specimens housed at the Herpetological Collection of the Federal University of Juiz de Fora (CHUFJF-Reptiles) and published papers. Better documentation of the reptilian fauna for the region not only expands the knowledge of the herpetofauna of Minas Gerais, but also contributes to regional conservation planning, such as "Biota Minas" program in the states of the Minas Gerais, Brazil. A total of 41 reptile species (two freshwater turtles, two amphisbaenians, 13 lizards and 24 snakes) belonging to 12 families were recorded. We highlight the record of the freshwater turtle Hydromedusa maximiliani, which is considered a species sensitive to anthropogenic impact and currently is seen only in protected areas in Juiz de Fora, as well as Ecpleopus gaudichaudii, Enyalius brasiliensis, Heterodactylus imbricatus, Placosoma glabellum and Micrurus corallinus, that are dependent on well-preserved forest areas. The reptile composition is more similar to Viçosa and other surrounding regions, despite the presence of many species that are not shared between these locations. This fact demonstrates the importance of the collection in terms of representativeness of the local and regional fauna as well as providing a valuable source of information for future studies of Brazilian herpetofauna in general.


2018 ◽  
Vol 2 (2) ◽  
pp. 63-70 ◽  
Author(s):  
R. Obour

Broussonetia papyrifera is an exotic tree widely grown for paper production. Due to its prolific regeneration it has invaded forestcanopy gaps and degraded farmlands and has now become an invasive species in Ghana. In enhancing its value for use the plantwas evaluated as potential forage for grazing animals vis-à-vis other two existing forage plants: Ficus exasperata and Leucaenaleucocephala.The study assessed the palatability and preference of Broussonetia papyrifera using sheep and goats for the wet anddry seasons.The species were assessed in indoor pen feeding trials using eight-unit (3×3 m) pens with the cafeteria method.The amount of forage offered was 100g (fresh material) in all instances for each species and for ten minutes. Adesign basedon 3×2×2 factorial in Randomized Complete Block Design (RCBD) was used to test the differences in palatability betweenthe three forage species.Results revealed that palatability was higher (P<0.05) in Leucaena leucocephala compared with Ficusexasperata and Broussonetia papyrifera for sheep and goats across seasons. The trend shown might be the result of the effectsof familiarity with the Leucaena leucocephala since animals tend to select plants that are familiar than newly introduced andunfamiliar plants. The study also revealed high level of condensed tannin (CT) in Broussonetia papyrifera which might haveinterfered with forage intake by the animals.There were no significant differences in palatability of Broussonetia papyrifera forgoat in both dry and wet season interactions and Ficus exasperata for goat in both dry and wet season interactions (P>0.05).Thestudy concluded that Broussonetia papyrifera could be a potential feed for both sheep and goats across seasons.The researchrecommended that livestock farmers should incorporate Broussonetia papyrifera feed into their programmes for both sheep andgoats and should be introduced to animals from infancy so that it may become a familiar feed for them.


Diversity ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 71
Author(s):  
Charalampos Dimitriadis ◽  
Ivoni Fournari-Konstantinidou ◽  
Laurent Sourbès ◽  
Drosos Koutsoubas ◽  
Stelios Katsanevakis

Understanding the interactions among invasive species, native species and marine protected areas (MPAs), and the long-term regime shifts in MPAs is receiving increased attention, since biological invasions can alter the structure and functioning of the protected ecosystems and challenge conservation efforts. Here we found evidence of marked modifications in the rocky reef associated biota in a Mediterranean MPA from 2009 to 2019 through visual census surveys, due to the presence of invasive species altering the structure of the ecosystem and triggering complex cascading effects on the long term. Low levels of the populations of native high-level predators were accompanied by the population increase and high performance of both native and invasive fish herbivores. Subsequently the overgrazing and habitat degradation resulted in cascading effects towards the diminishing of the native and invasive invertebrate grazers and omnivorous benthic species. Our study represents a good showcase of how invasive species can coexist or exclude native biota and at the same time regulate or out-compete other established invaders and native species.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Adam G. Clause ◽  
Aaron J. Celestian ◽  
Gregory B. Pauly

AbstractPlastic pollution, and especially plastic ingestion by animals, is a serious global issue. This problem is well documented in marine systems, but it is relatively understudied in freshwater systems. For turtles, it is unknown how plastic ingestion compares between marine and non-marine species. We review the relevant turtle dietary literature, and find that plastic ingestion is reported for all 7 marine turtle species, but only 5 of 352 non-marine turtle species. In the last 10 years, despite marine turtles representing just 2% of all turtle species, almost 50% of relevant turtle dietary studies involved only marine turtles. These results suggest that the potential threat of plastic ingestion is poorly studied in non-marine turtles. We also examine plastic ingestion frequency in a freshwater turtle population, finding that 7.7% of 65 turtles had ingested plastic. However, plastic-resembling organic material would have inflated our frequency results up to 40% higher were it not for verification using Raman spectroscopy. Additionally, we showcase how non-native turtles can be used as a proxy for understanding the potential for plastic ingestion by co-occurring native turtles of conservation concern. We conclude with recommendations for how scientists studying non-marine turtles can improve the implementation, quality, and discoverability of plastic ingestion research.


AI and Ethics ◽  
2021 ◽  
Author(s):  
Muhammad Ali Chaudhry ◽  
Emre Kazim

AbstractIn the past few decades, technology has completely transformed the world around us. Indeed, experts believe that the next big digital transformation in how we live, communicate, work, trade and learn will be driven by Artificial Intelligence (AI) [83]. This paper presents a high-level industrial and academic overview of AI in Education (AIEd). It presents the focus of latest research in AIEd on reducing teachers’ workload, contextualized learning for students, revolutionizing assessments and developments in intelligent tutoring systems. It also discusses the ethical dimension of AIEd and the potential impact of the Covid-19 pandemic on the future of AIEd’s research and practice. The intended readership of this article is policy makers and institutional leaders who are looking for an introductory state of play in AIEd.


Oryx ◽  
2013 ◽  
Vol 47 (4) ◽  
pp. 607-615 ◽  
Author(s):  
James E. Paterson ◽  
Brad D. Steinberg ◽  
Jacqueline D. Litzgus

AbstractThe viability of freshwater turtle populations is largely dependent on the survivorship of reproducing females but females are frequently killed on roads as they move to nesting sites. Installing artificial nesting mounds may increase recruitment and decrease the risk of mortality for gravid females by enticing them to nest closer to aquatic habitats. We evaluated the effectiveness of artificial nesting mounds installed in Algonquin Park, Canada. Artificial mounds were monitored for 2 years to determine if turtles would select them for nest sites. We also simulated turtle paths from wetlands to nests to determine the probability that females would encounter the new habitat. A transplant experiment with clutches of Chrysemys picta and Chelydra serpentina eggs compared nest success and incubation conditions in the absence of predation between artificial mounds and natural sites. More turtles than expected used the artificial mounds, although mounds comprised a small proportion of the available nesting habitat and the simulations predicted that the probability of females encountering mounds was low. Hatching success was higher in nests transplanted to artificial mounds (93%) than in natural nests (56%), despite no differences in heat units. Greater use than expected, high hatching success, and healthy hatchlings emerging from nests in artificial mounds suggest promise for their use as conservation tools.


Cells ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1962
Author(s):  
Muhammad Aslam ◽  
Yury Ladilov

An outbreak of the novel coronavirus (CoV) SARS-CoV-2, the causative agent of COVID-19 respiratory disease, infected millions of people since the end of 2019, led to high-level morbidity and mortality and caused worldwide social and economic disruption. There are currently no antiviral drugs available with proven efficacy or vaccines for its prevention. An understanding of the underlying cellular mechanisms involved in virus replication is essential for repurposing the existing drugs and/or the discovery of new ones. Endocytosis is the important mechanism of entry of CoVs into host cells. Endosomal maturation followed by the fusion with lysosomes are crucial events in endocytosis. Late endosomes and lysosomes are characterized by their acidic pH, which is generated by a proton transporter V-ATPase and required for virus entry via endocytic pathway. The cytoplasmic cAMP pool produced by soluble adenylyl cyclase (sAC) promotes V-ATPase recruitment to endosomes/lysosomes and thus their acidification. In this review, we discuss targeting the sAC-specific cAMP pool as a potential strategy to impair the endocytic entry of the SARS-CoV-2 into the host cell. Furthermore, we consider the potential impact of sAC inhibition on CoV-induced disease via modulation of autophagy and apoptosis.


2012 ◽  
Vol 39 (8) ◽  
pp. 705 ◽  
Author(s):  
Deborah S. Bower ◽  
Clare E. Death ◽  
Arthur Georges

Context The increasing intensity and extent of anthropogenically mediated salinisation in freshwater systems has the potential to affect freshwater species through physiological and ecological processes. Determining responses to salinisation is critical to predicting impacts on fauna. Aims We aimed to quantify the response of wild-caught turtles from freshwater lakes that had become saline in the lower Murray River catchment. Methods Plasma electrolytes of all three species of freshwater turtle from South Australia were compared among two freshwater sites (Horseshoe Lagoon and Swan Reach), a brackish lake (Lake Bonney) and a saline lake (Lake Alexandrina). Key results Chelodina longicollis, C. expansa and Emydura macquarii from a brackish lake had higher concentrations of plasma sodium and chloride than those from freshwater habitats. However, osmolytes known to increase under severe osmotic stress (urea and uric acid) were not elevated in brackish sites. Turtles from the highly saline lake were colonised by an invasive marine worm which encased the carapace and inhibited limb movement. Conclusions Freshwater turtles in brackish backwaters had little response to salinity, whereas the C. longicollis in a saline lake had a significant physiological response caused by salt and further impacts from colonisation of marine worms. Implications Short periods of high salinity are unlikely to adversely affect freshwater turtles. However, secondary ecological processes, such as immobilisation from a marine worm may cause unexpected impacts on freshwater fauna.


Sign in / Sign up

Export Citation Format

Share Document