Southern elephant seals (Mirounga leonina) typically give birth to a single pup and raise it over a short 24-day lactation period. Lactation is characterised by: maternal fasting, rapid pup growth and abrupt weaning after which the weaned pups rely on stored fat for growth and survival. Females are not able to transfer all of their stored resources to their pups because they themselves need to use some to return to their remote foraging grounds after the breeding effort. Therefore the amount of energy expended by a female during lactation may affect not only the survival of her pup, but her own survival and future reproductive success. Female southern elephant seals are therefore under strong selective pressure to allocate finite amounts of resources to their pups. In the rare event of producing twins, females that wean both pups are likely to experience reduced reproductive success. Twin births accounted for 0.38% of all the observed elephant seal births at Macquarie Island in 1999. The mean birth masses, weaning lengths and lactation duration for twin and singleton pups did not differ significantly but weaning mass, weaning girths and lactation growth rates did differ significantly. In all cases, singleton pups were larger and grew faster than twin pups. Twin pups suffered greater pre-weaning mortality than singletons (16.7% and 4.6% respectively) and fewer were seen alive after 18 months (20% compared with 47% respectively).
Scats were collected from itinerant male Hooker's sea lions, Phocarctos hookeri, at Macquarie Island and the uneroded faunal remains used to assess the diet. Uneroded sagittal otoliths were used to identify teleost fish and to calculate fish size. Prey items included 14 taxa of teleost fish, cephalopods, gastropods, crustaceans and fur seals. Fish constituted the primary component of the diet. Prey species previously uncommon in the diet of seals and penguins around Macquarie Island were commonly eaten by Hooker's sea lions. The sub-Antarctic horse fish (Zanclorhynchus spinifer) and the Patagonian tooth fish (Dissostichus eleginoides) were the two most abundant species and occurred in 62.5% and 41.7% of all scats respectively. There were no age-specific and individual differences in the diet of sea lions. Seasonal variances in diet were absent. Small plastic fragments (diameter ∼1 mm) were found only in association with otoliths of Electrona subaspera. Some overlap was seen between the diet of itinerant male Hooker's sea lions and the commercial fisheries that currently operate around Macquarie Island.
Wildlife researchers and conservation biologists are encountering growing research difficulties due to strong and effective advocacy of animal welfare concerns. However, collecting information on the basic biology of animals, which is often essential to effective conservation and management, frequently involves invasive research. The latter is unacceptable to some animal welfare advocates, even if it ultimately leads to better conservation outcomes. For effective biodiversity conservation it is imperative that conservation and wildlife researchers lucidly present the case for their research on individual animals. This requires conservation biologists and the research community in general, to present these arguments in the public domain as well as in peer-reviewed literature. Moreover, it is important to measure how these activities affect animals. Only then can we show that high quality research activities often have little or no effects on animal vital rates and performance.
Context Spread of the invasive cane toad (Rhinella marina) across northern Australia is of concern. Predator species, including the freshwater crocodile (Crocodylus johnstoni), are susceptible to cane toad toxins when ingested. Upstream populations of freshwater crocodiles are smaller than downstream counterparts because of limited resources. We measured the impact of cane toad arrival on densities of these upstream populations.
Aims Our aim was to determine whether the influx of cane toads had a negative impact on populations of upstream 'stunted' freshwater crocodiles.
Methods Population surveys for crocodiles were conducted in three upstream creek systems, using day- and night-based survey methods, before the arrival of cane toads in the area. These surveys were repeated under similar conditions following the arrival of cane toads, to compare the distribution and densities of freshwater crocodiles and, hence, measure the impact of cane toads.
Key results There were significant declines in crocodile density at two survey sites following the arrival of cane toads, and we found dead crocodiles and cane toad carcasses with crocodile bite marks. The third site showed no change in density. There was a decline in mean density across all sites from 3.0 crocodiles km–1 to 1.1 crocodiles km–1 following the arrival of cane toads.
Conclusions There was an overall decrease in crocodile densities and a reduction in distribution following the arrival of cane toads into the survey area. Dead crocodiles and evidence of their having eaten cane toads strongly suggest that these declines were caused directly by the arrival of cane toads into the area. One site showed no apparent change other than an increase in wariness, which may reflect the distribution of available feeding and shelter resources among the three sites.
Implications These results suggest that upstream freshwater crocodile populations are highly susceptible to cane toad toxins, and that impacts on their population can include local extirpation. Considering their morphological and possibly genetic distinctiveness, the loss of these unique populations is of conservation concern.
Context Following centuries of intense human exploitation, the global stocks of hawksbill turtle have decreased precipitously and the species is currently considered Critically Endangered by the IUCN. Australia supports the largest breeding aggregations worldwide; however, there are no accurate estimates of population abundance and seasonality for hawksbill turtles at important nesting grounds in eastern Arnhem Land.
Aims This study was designed to fill in this lack of ecological information and assist with the conservation and management of hawksbill turtles. More specifically, our overarching goals were to assess nesting seasonality, habitat preferences and provide the first estimate of annual nesting population size at a Northern Territory rookery.
Methods In 2009 and 2010 we collected beach monitoring, satellite telemetry and sand temperature data over two nesting seasons at a group of three islands located 30 km off Groote Eylandt in the Gulf of Carpentaria, northern Australia. We subsequently analysed these data to unravel hawksbill nesting behaviour and reproductive outputs, and examined the vulnerability of this rookery to climate change.
Key results Hawksbill turtle nesting seasonality consistently started in mid-May, peaked in mid-August and ended in late November. Annual nesting abundance showed a near 3-fold increase between 2009 and 2010, with an average of 220 and 580 hawksbill females nesting on this island group respectively. Sand temperature at 50 cm reached more than 30°C at all monitored sites during most of the peak of the incubation period.
Conclusions This remote and untouched group of islands constitutes a major hawksbill turtle rookery both nationally and globally. While anthropogenic impacts and predation are low year round, climate change threatens to skew hatchling sex ratios, eventually leading to an increase in hatchling mortality.
Implications Additional ground-based surveys are required to refine the accuracy of population estimates presented in this study. Given the paucity of data in the region, we recommend this island group off Groote Eylandt be used as a population-monitoring index site for the eastern Arnhem Land hawksbill turtle breeding aggregation.
Context Some large herbivores introduced to Australia have achieved population densities so high as to cause considerable ecological damage. Intriguingly, others have been relatively less successful and have correspondingly perturbed their new environments less. An excellent example is two similar-sized bovine species that established feral populations in the Northern Territory of Australia in the mid-19th century. Asian swamp buffalo (Bubalus bubalis) rapidly colonised the tropical savannas, causing ecological degradation, especially on freshwater swamps. In contrast, banteng (Bos javanicus) are restricted to their point of introduction and have caused relatively negligible ecological damage. Understanding the reasons of this differential success is of theoretical and applied interest and contributes to managing large herbivore populations for ex situ conservation and feral-animal control. Aims To compare the population structure of buffalo and banteng on the basis of shot samples, so as to construct life tables for four contemporary (low-density) buffalo populations, and collated data from previous work from three historical (high-density) buffalo populations and one banteng population (the only extant ex situ population in existence). Further, to provide a validation of age estimation with and without informed priors in a Bayesian model comparing horn length and ages estimated from tooth cementum annuli. Finally, to interpret our results in the context of relative invasion potential of the two bovid species. Key Results For both species, survival of juveniles was the most important demographic component influencing deterministic population growth. However, buffalo have the demographic capacity to recover swiftly after control because of high survival and fertility rates across a range of population densities. Fertility of buffalo was historically greater than that of banteng, and buffalo fertility increased as their populations were reduced. Conclusions These findings highlight how subtle differences in demographic rates and feeding ecology can influence the success (high population growth and range expansion) of large herbivores, knowledge which is increasingly important for managing invasive species effectively. Implications We show that that individual life-history traits and demographic performance, especially fertility, play an important role in determining the spread of invasive bovids in a novel environment.
Context. Understanding how the individual movement patterns and dispersion of a population change following wildlife management interventions is crucial for effective population management. Aims. We quantified the impacts of two wildlife management strategies, a lethal intervention and a subsequent barrier intervention, on localised populations of the two most common macropod species in Tasmania, the Tasmanian pademelon (Thylogale billardierii) and the red-necked wallaby (Macropus rufogriseus rufogriseus). This manipulation allowed us to examine two competing hypotheses concerning the distribution of individuals in animal populations – the Ideal Free Distribution (IFD) hypothesis and the Rose Petal (RP) hypothesis. We predicted that the RP would be supported if individuals maintained their previous home ranges following intervention, whereas the IFD would be supported if individuals redistributed following the management interventions. Methods. The movement patterns of T. billardierii and M. r. rufogriseus were tracked using GPS technology before and after the two management interventions. Key results. Following lethal intervention, pademelons and wallabies (1) maintained their home-range area, (2) increased their utilisation of agricultural habitat and (3) shifted their mean centroid locations compared with the pre-intervention period. Following barrier intervention, pademelons and wallabies (1) maintained their home-range area, (2) decreased their utilisation of agricultural habitat and (3) shifted their mean centroid locations compared with the pre-intervention period. Conclusions. On the basis of the individual responses of macropods to the management strategies (1) lethal intervention appeared to induce small shifts in home-range distributions of those remaining individuals in the population with home ranges overlapping the areas of lethal intervention and (2) barrier intervention is likely to induce whole-scale population movements of the animals that survive the lethal intervention in their search of an alternative food source. Both species displayed spatial and temporal shifts in their home-range distributions in response to lethal and barrier interventions that appear to conform broadly to predictions of IFD, at least in the timeframe of the present experiment. Implications. Wildlife management strategies, which are increasingly constrained by ethical, socio-political and financial considerations, should be based on ecological and behavioural data regarding the likely responses of the target population.
Hot-iron brands were used to mark permanently 14 000 six-week-old southern elephant seal (Mirounga leonina L.) pups at Macquarie Island between 1993 and 2000. We assessed temporal changes in the quality of 4932 brands applied in 1998 and 1999 to determine the duration of the brand wound, and the relationships between brand healing, brand readability and the amount of skin and hair damage peripheral to the brand characters. Most (98%) brand wounds were healed within one year. Brand-mark healing, peripheral skin damage and brand readability were significantly (P < 0.05) correlated. The proportion of healed and readable brands increased in the population during the first annual moult, and thereafter these proportions remained high (>95%) for the marked population. The mean number of brand characters with peripheral skin damage decreased significantly over the same period. The seal's annual hair and skin moult is the process that contributed most to the healing of brand wounds. We also assessed our branding technique to determine whether any of the features we measured contributed to a poor-quality brand. Excessive pressure used during brand-iron application is the most probable cause of unsightly peripheral skin damage, but this damage is short lived.
The coronavirus disease 2019 (COVID-19) pandemic is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This pathogen has spread rapidly across the world, causing high numbers of deaths and significant social and economic impacts. SARS-CoV-2 is a novel coronavirus with a suggested zoonotic origin with the potential for cross-species transmission among animals. Antarctica can be considered the only continent free of SARS-CoV-2. Therefore, concerns have been expressed regarding the potential human introduction of this virus to the continent through the activities of research or tourism to minimise the effects on human health, and the potential for virus transmission to Antarctic wildlife. We assess the reverse-zoonotic transmission risk to Antarctic wildlife by considering the available information on host susceptibility, dynamics of the infection in humans, and contact interactions between humans and Antarctic wildlife. The environmental conditions in Antarctica seem to be favourable for the virus stability. Indoor spaces such as those at research stations, research vessels or tourist cruise ships could allow for more transmission among humans and depending on their movements between different locations the virus could be spread across the continent. Among Antarctic wildlife previous in silico analyses suggested that cetaceans are at greater risk of infection whereas seals and birds appear to be at a low infection risk. However, caution needed until further research is carried out and consequently, the precautionary principle should be applied. Field researchers handling animals are identified as the human group posing the highest risk of transmission to animals while tourists and other personnel pose a significant risk only when in close proximity (< 5 m) to Antarctic fauna. We highlight measures to reduce the risk as well as identify of knowledge gaps related to this issue. ; This work is an outcome of the Working Group of Wildlife Health Monitoring of the SCAR Expert Group of Birds and Marine Mammals. AB is supported by the Spanish Research Agency project (CTM2015-64720). AG is supported by the Defence Advanced Research Projects Agency (DARPA PREEMPT Cooperative Agreement No. D18AC00031). The content of the information does not necessarily reflect the position or the policy of the US government, and no official endorsement should be inferred. AV is supported by National Science Foundation (USA) Polar program (award # 1947040). CRM is supported by Australia's Integrated Marine Observing System. IMOS is enabled by the National Collaborative Research Infrastructure Strategy (NCRIS). It is operated by a consortium of institutions as an unincorporated joint venture, with the University of Tasmania as Lead Agent. JID is supported by Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) and Universidad Nacional de La Plata UNLP (N#859). VM is supported by National Science Foundation (USA) Polar program (PLR 1543459). TB is supported by CNRS, French Polar Institute Project ECOPATH (IPEV 1151), ZATA and OSU OREME. DGA is supported by INACH T-23-19 project. ; Peer reviewed
Funding and support for the November 2019 Network Development Workshop was provided by the Integrated Marine Observing System (IMOS) and the Australia Research Council's Special Research Initiative for Antarctic Gateway Partnership (SR140300001) through the University of Tasmania's Institute of Marine and Antarctic Studies. IMOS is a national collaborative research infrastructure, supported by the Australian Government and operated by a consortium of institutions as an unincorporated joint venture, with the University of Tasmania as Lead Agent. This research contributes to the Australian Research Council Discovery Project DP180101667 and DP210103091. SBe was supported under the Australian Research Council DECRA DE180100828. IJ was supported by Macquarie University's co-Funded Fellowship Program with external partners: Office of Naval Research (N00014-18-1-2405); the Integrated Marine Observing System – Animal Tracking Facility; the Ocean Tracking Network; Taronga Conservation Society; Birds Canada; and Innovasea/Vemco. AS was supported by a 2020 Pew Fellowship in Marine Conservation. DM was supported by the European Union's Horizon 2020 Research and Innovation Program under the Marie Skłodowska-Curie grant agreement (No. 794938). ; Marine animals equipped with biological and physical electronic sensors have produced long-term data streams on key marine environmental variables, hydrography, animal behavior and ecology. These data are an essential component of the Global Ocean Observing System (GOOS). The Animal Borne Ocean Sensors (AniBOS) network aims to coordinate the long-term collection and delivery of marine data streams, providing a complementary capability to other GOOS networks that monitor Essential Ocean Variables (EOVs), essential climate variables (ECVs) and essential biodiversity variables (EBVs). AniBOS augments observations of temperature and salinity within the upper ocean, in areas that are under-sampled, providing information that is urgently needed for an improved understanding of climate and ocean variability and for forecasting. Additionally, measurements of chlorophyll fluorescence and dissolved oxygen concentrations are emerging. The observations AniBOS provides are used widely across the research, modeling and operational oceanographic communities. High latitude, shallow coastal shelves and tropical seas have historically been sampled poorly with traditional observing platforms for many reasons including sea ice presence, limited satellite coverage and logistical costs. Animal-borne sensors are helping to fill that gap by collecting and transmitting in near real time an average of 500 temperature-salinity-depth profiles per animal annually and, when instruments are recovered (∼30% of instruments deployed annually, n = 103 ± 34), up to 1,000 profiles per month in these regions. Increased observations from under-sampled regions greatly improve the accuracy and confidence in estimates of ocean state and improve studies of climate variability by delivering data that refine climate prediction estimates at regional and global scales. The GOOS Observations Coordination Group (OCG) reviews, advises on and coordinates activities across the global ocean observing networks to strengthen the effective implementation of the system. AniBOS was formally recognized in 2020 as a GOOS network. This improves our ability to observe the ocean's structure and animals that live in them more comprehensively, concomitantly improving our understanding of global ocean and climate processes for societal benefit consistent with the UN Sustainability Goals 13 and 14: Climate and Life below Water. Working within the GOOS OCG framework ensures that AniBOS is an essential component of an integrated Global Ocean Observing System. ; Publisher PDF ; Peer reviewed
The global lockdown to mitigate COVID-19 pandemic health risks has altered human interactions with nature. Here, we report immediate impacts of changes in human activities on wildlife and environmental threats during the early lockdown months of 2020, based on 877 qualitative reports and 332 quantitative assessments from 89 different studies. Hundreds of reports of unusual species observations from around the world suggest that animals quickly responded to the reductions in human presence. However, negative effects of lockdown on conservation also emerged, as confinement resulted in some park officials being unable to perform conservation, restoration and enforcement tasks, resulting in local increases in illegal activities such as hunting. Overall, there is a complex mixture of positive and negative effects of the pandemic lockdown on nature, all of which have the potential to lead to cascading responses which in turn impact wildlife and nature conservation. While the net effect of the lockdown will need to be assessed over years as data becomes available and persistent effects emerge, immediate responses were detected across the world. Thus, initial qualitative and quantitative data arising from this serendipitous global quasi-experimental perturbation highlights the dual role that humans play in threatening and protecting species and ecosystems. Pathways to favorably tilt this delicate balance include reducing impacts and increasing conservation effectiveness. ; The Canada Research Chairs program provided funding for the core writing team. Field research funding was provided by A.G. Leventis Foundation; Agence Nationale de la Recherche, [grant number ANR-18-32–0010CE-01 (JCJC PEPPER)]; Agencia Estatal de Investigaci; Agência Regional para o Desenvolvimento da Investigação Tecnologia e Inovação (ARDITI), [grant number M1420-09-5369-FSE-000002]; Alan Peterson; ArcticNet; Arkadaşlar; Army Corp of Engineers; Artificial Reef Program; Australia's Integrated Marine Observing System (IMOS), National Collaborative; Research Infrastructure Strategy (NCRIS), University of Tasmania; Australian Institute of Marine Science; Australian Research Council, [grant number LP140100222]; Bai Xian Asia Institute; Batubay Özkan; BC Hydro Fish and Wildlife Compensation Program; Ben-Gurion University of the Negev; Bertarelli Foundation; Bertarelli Programme in Marine Science; Bilge Bahar; Bill and Melinda Gates Foundation; Biology Society of South Australia; Boston University; Burak Över; California State Assembly member Patrick O'Donnell; California State University Council on Ocean Affairs, Science & Technology; California State University Long Beach; Canada Foundation for Innovation (Major Science Initiative Fund and funding to Oceans Network Canada), [grant number MSI 30199 for ONC]; Cape Eleuthera Foundation; Centre National d'Etudes Spatiales; Centre National de la Recherche Scientifique; Charles Darwin Foundation, [grant number 2398]; Colombian Institute for the Development of Science and Technology (COLCIENCIAS), [grant number 811–2018]; Colombian Ministry of Environment and Sustainable Development, [grant number 0041–2020]; Columbia Basin Trust; Commission for Environmental Cooperation; Cornell Lab of Ornithology; Cultural practices and environmental certification of beaches, Universidad de la Costa, Colombia, [grant number INV.1106–01–002-15, 2020–21]; Department of Conservation New Zealand; Direction de l'Environnement de Polynésie Française; Disney Conservation Fund; DSI-NRF Centre of; Excellence at the FitzPatrick Institute of African Ornithology; Ecology Project International; Emin Özgür; Environment and Climate Change Canada; European Community: RTD programme - Species Support to Policies; European Community's Seventh Framework Programme; European Union; European Union's Horizon 2020 research and innovation programme, Marie Skłodowska-Curie, [grant number 798091, 794938]; Faruk Eczacıbaşı; Faruk Yalçın Zoo; Field research funding was provided by King Abdullah University of Science and Technology; Fish and Wildlife Compensation Program; Fisheries and Oceans Canada; Florida Fish and Wildlife Conservation Commission, [grant numbers FWC-12164, FWC-14026, FWC-19050]; Fondo Europeo de Desarrollo Regional; Fonds québécois de la recherche nature et technologies; Foundation Segré; Fundação para a Ciência e a Tecnologia (FCT Portugal); Galapagos National Park Directorate research, [grant number PC-41-20]; Gordon and Betty Moore Foundation, [grant number GBMF9881 and GBMF 8072]; Government of Tristan da Cunha; Habitat; Conservation Trust Foundation; Holsworth Wildlife Research Endowment; Institute of Biology of the Southern Seas, Sevastopol, Russia; Instituto de Investigación de Recursos Biológicos Alexander von Humboldt; Instituto Nacional de Pesquisas Espaciais (INPE), Brazil; Israeli Academy of Science's Adams Fellowship; King Family Trust; Labex, CORAIL, France; Liber Ero Fellowship; LIFE (European Union), [grant number LIFE16 NAT/BG/000874]; Mar'a de Maeztu Program for Units of Excellence in R&D; Ministry of Science and Innovation, FEDER, SPASIMM,; Spain, [grant number FIS2016–80067-P (AEI/FEDER, UE)]; MOE-Korea, [grant number 2020002990006]; Mohamed bin Zayed Species Conservation Fund; Montreal Space for Life; National Aeronautics and Space Administration (NASA) Earth and Space Science Fellowship Program; National Geographic Society, [grant numbers NGS-82515R-20]; National Natural Science Fund of China; National Oceanic and Atmospheric Administration; National Parks Board, Singapore; National Science and Technology Major Project of China; National Science Foundation, [grant number DEB-1832016]; Natural Environment Research Council of the UK; Natural Sciences and Engineering Research Council of Canada (NSERC), Alliance COVID-19 grant program, [grant numbers ALLRP 550721–20, RGPIN-2014-06229 (year: 2014), RGPIN-2016-05772 (year: 2016)]; Neiser Foundation; Nekton Foundation; Network of Centre of Excellence of Canada: ArcticNet; North Family Foundation; Ocean Tracking Network; Ömer Külahçıoğlu; Oregon State University; Parks Canada Agency (Lake Louise, Yoho, and Kootenay Field Unit); Pew Charitable Trusts; Porsim Kanaf partnership; President's International Fellowship Initiative for postdoctoral researchers Chinese Academy of Sciences, [grant number 2019 PB0143]; Red Sea Research Center; Regional Government of the Azores, [grant number M3.1a/F/025/2015]; Regione Toscana; Rotary Club of Rhinebeck; Save our Seas Foundation; Science & Technology (CSU COAST); Science City Davos, Naturforschende Gesellschaft Davos; Seha İşmen; Sentinelle Nord program from the Canada First Research Excellence Fund; Servizio Foreste e Fauna (Provincia Autonoma di Trento); Sigrid Rausing Trust; Simon Fraser University; Sitka Foundation; Sivil Toplum Geliştirme Merkezi Derneği; South African National Parks (SANParks); South Australian Department for Environment and Water; Southern California Tuna Club (SCTC); Spanish Ministry for the Ecological Transition and the Demographic Challenge; Spanish Ministry of Economy and Competitiveness; Spanish Ministry of Science and Innovation; State of California; Sternlicht Family Foundation; Suna Reyent; Sunshine Coast Regional Council; Tarea Vida, CEMZOC, Universidad de Oriente, Cuba, [grant number 10523, 2020]; Teck Coal; The Hamilton Waterfront Trust; The Ian Potter Foundation, Coastwest, Western Australian State NRM; The Red Sea Development Company; The Wanderlust Fund; The Whitley Fund; Trans-Anatolian Natural Gas Pipeline; Tula Foundation (Hakai Institute); University of Arizona; University of Pisa; US Fish and Wildlife Service; US Geological Survey; Valencian Regional Government; Vermont Center for Ecostudies; Victorian Fisheries Authority; VMRC Fishing License Fund; and Wildlife Warriors Worldwide.