Vinay Udyawer

Large predator attacks on humans often provoke calls for animal population reduction, assuming it will reduce such incidents. Whilst this seems logical, there is currently little evidence supporting a consistent link between large predator density and attacks on humans. Here, we assessed whether large predator density is linked to the frequency of...

Tag-recapture programs to monitor the movements of fish populations are among some of the longest-running citizen-science datasets to date. Here, using half a century of yellowtail kingfish (Seriola lalandi, Carangidae) tag-recapture data collected through citizen-science projects, we report novel insights into population connectivity in Australia...

Background Accurate predictions of animal occurrence in time and space are crucial for informing and implementing science-based management strategies for threatened species. Methods We compiled known, available satellite tracking data for pygmy blue whales in the Eastern Indian Ocean (n = 38), applied movement models to define low (foraging and re...

Many shark populations are in decline around the world, with severe ecological and economic consequences. Fisheries management and marine protected areas (MPAs) have both been heralded as solutions. However, the effectiveness of MPAs alone is questionable, particularly for globally threatened sharks and rays (‘elasmobranchs’), with little known abo...

Background Acoustic telemetry has become a fundamental tool to monitor the movement of aquatic species. Advances in technology, in particular the development of batteries with lives of > 10 years, have increased our ability to track the long-term movement patterns of many species. However, logistics and financial constraints often dictate the locat...

The transition from terrestrial to aquatic life by hydrophiine elapid snakes modified targets of natural selection and likely affected sexual selection also. Thus, the shift to marine life also might have affected sexual dimorphism. Our measurements of 419 preserved specimens of six species of aipysurine snakes (genera Emydocephalus and Aipysurus)...

Opportunistic observations of Erabu sea kraits (Laticauda semifaciata) provide evidence that this species undertake a novel foraging tactic; coordinated communal hunting. Erabu sea kraits prey on cryptic fish species in highly complex reef habitats. Intra- and interspecific cooperative hunting strategies may increase chances for all members of the...

One-third of all elasmobranchs (sharks and rays) are threatened with extinction. Euryhaline and estuarine generalist elasmobranchs are a group of 29 species that occupy non-marine environments during particular life-stages. These species are poorly known and disproportionately threatened, with 72.4% at risk of extinction or Data Deficient. A detail...

The capacity for individuals to move long distances can profoundly influence how species are affected by localised threatening processes. Previous studies on the movement patterns of sea snakes have highlighted the highly site-attached nature of some species, but constraints on collecting data at large spatial and temporal scales have underestimate...

Habitat associations and preferences of animals can be inferred from how long they remain within close proximity to a certain location. The residency index (RI) is a common metric used in acoustic telemetry studies to assess how long an individual spends in an area. However, the methods used to calculate RI can affect the interpretation of telemetr...

A global survey of coral reefs reveals that overfishing is driving resident shark species toward extinction, causing diversity deficits in reef elasmobranch (shark and ray) assemblages. Our species level analysis revealed global declines of 60 to 73% for five common resident reef shark species and that individual shark species were not detected at...

Large‐bodied frugivores are essential to the ecological function of rainforest communities. The southern cassowary ( Casaurius casuarius johnsonii ) is the only large frugivore in the tropical rainforests of Australia. Here, we assessed whether cassowaries remain important to native plant seed dispersal in areas where the rainforest is highly fragm...

Opportunistic observation of Erabu sea snakes ( Laticauda semifaciata ) provide evidence that these species undertake a novel foraging tactic; coordinated communal hunting. Erabu sea snakes prey on cryptic fish species in highly complex reef habitats. Intra- and interspecific cooperative hunting strategies may increase chances for all members of th...

Opportunistic observation of Erabu sea snakes (Laticauda semifaciata) provide evidence that these species undertake a novel foraging tactic; coordinated communal hunting. Erabu sea snakes prey on cryptic fish species in highly complex reef habitats. Intra- and interspecific cooperative hunting strategies may increase chances for all members of the...

Wildlife tourism can assist species conservation through community-involvement and education, while contributing to regional economies. In the last decade, shark diving has become increasingly popular among wildlife tourists worldwide, including cage-diving with white sharks (Carcharodon carcharias). In Australia, birthplace of the white shark divi...

Unifying models have shown that the amount of space used by animals (e.g., activity space, home range) scales allometrically with body mass for terrestrial taxa; however, such relationships are far less clear for marine species. We compiled movement data from 1,596 individuals across 79 taxa collected using a continental passive acoustic telemetry...

The first survey of sea snakes (Elapidae, Hydrophiinae) at the remote Entrecasteaux atolls, Coral Sea, was conducted using remote unbaited 360° video cameras (RUV360), in 2021. We detected 49 snakes belonging to at least six species (Aipysurus duboisii, A. laevis, Hydrophis coggeri, H. macdowelli, H. major and H. ornatus) at the two largest atolls,...

Declines in abundance of sea snakes have been observed on reefs throughout the Indo-Pacific, although the reasons are unknown. To date, surveys have occurred on shallow reefs, despite sea snakes occurring over a large depth range. It is not known if populations of sea snakes in deep habitats have undergone similar declines. To address this, we anal...

Supporting the recovery of large carnivores is a popular yet challenging endeavour. Estuarine crocodiles in Australia are a large carnivore conservation success story, with the population having extensively recovered from past heavy exploitation. Here, we explored if dietary changes had accompanied this large population recovery by comparing the is...

Marine wildlife tourism is increasing in popularity, with operations targeting a wide range of taxa globally. While previous studies have mostly focused on assessing the effects of provisioning from tourism on focal species, non-focal species that unintentionally feed on supplemental food sources have largely been overlooked. This study improves ou...

Marine species and ecosystems are widely affected by anthropogenic stressors, ranging from pollution and fishing to climate change. Comprehensive assessments of how species and ecosystems are impacted by anthropogenic stressors are critical for guiding conservation and management investments. Previous global risk or vulnerability assessments have f...

Accessing the world's oceans is essential for monitoring and sustainable management of the maritime domain. Difficulty in reaching remote locations has resulted in sparse coverage, undermining our capacity to deter illegal activities and gather data for physical and biological processes. Uncrewed Surface Vessels (USVs) have existed for over two dec...

Background Information on site utilisation and movement is essential for managing species' resource requirements. Collecting these data requires frequent location sampling of multiple individuals, which can be challenging for small-bodied animals due to the often-large size of animal-borne satellite-based telemetry devices. We show how coded VHF-ra...

Over the past decade, vertebrate populations globally have experienced significant declines in distribution and abundance. Understanding the reasons behind these population declines is the first step in implementing appropriate management responses to improve conservation outcomes. Uncovering drivers of extirpation events after the fact, however, r...

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. Hundr...

Delineation of population structure (i.e. stocks) is crucial to successfully manage exploited species and to address conservation concerns for threatened species. Fish migration and associated movements are key mechanisms through which discrete populations mix and are thus important determinants of population structure. Detailed information on fish...

COVID-19 restrictions have led to an unprecedented global hiatus in anthropogenic activities, providing a unique opportunity to assess human impact on biological systems. Here, we describe how a national network of acoustic tracking receivers can be leveraged to assess the effects of human activity on animal movement and space use during such globa...

1. Research on interactions between humans and deadly snakes has focused on situ- ations that result in high rates of snakebite; but we can also learn from cases where snakes and people coexist peacefully. For example, coastal bays near Noumea, in the Pacific archipelago of New Caledonia, are used by thousands of tourists and snakes, but bites are...

A common strategy used to conserve turtles is to increase the number of hatchlings entering the population by protecting the nests. Typically, nest protection programs require regular and systematic abundance surveys conducted over lengthy periods between oviposition and sexual maturity (20+ years) to assess if this conservation strategy is effecti...

Morphological features that impair a predator's ability to consume a prey item may benefit individual prey; but what of features that prolong prey‐handling but do not enhance prey survival? For example, a striped eel catfish Plotosus lineatus will be fatally envenomated if struck by its specialist predator, the greater sea snake Hydrophis major. No...

The fitness of a predator depends upon its ability to locate and capture prey; and thus, increasing dietary specialization should favor the evolution of species-specific foraging tactics tuned to taxon-specific habitats and cues. Within marine environments, prey detectability (e.g., via visual or chemical cues) is affected by environmental conditio...

An Amendment to this paper has been published and can be accessed via a link at the top of the paper.

Using depth sensor transmitters and an array of acoustic receivers to monitor the facultative air-breathing Australian lungfish (Neoceratodus forsteri), we investigated habitat preferences and behavioral responses to seasonal hypoxic zones in a riverine impoundment. Threedimensional (3-D) kernel utilisation distribution (KUD) models revealed that d...

A common strategy used to conserve turtles is to increase the number of hatchlings entering the population by protecting the nests. Typically, nest protection programs require regular and systematic abundance surveys conducted over lengthy periods between oviposition and sexual maturity (20+ years) to assess if this conservation strategy is effecti...

Decades of overexploitation have devastated shark populations, leaving considerable doubt as to their ecological status1,2. Yet much of what is known about sharks has been inferred from catch records in industrial fisheries, whereas far less information is available about sharks that live in coastal habitats³. Here we address this knowledge gap usi...

Information on the spatial ecology of reef sharks is critical to understanding life-history patterns, yet gaps remain in our knowledge of how these species move and occupy space. Previous studies have focused on offshore reefs and atolls with little information available on the movement and space use of sharks utilising reef habitats closer to shor...

Strategies aimed to conserve and manage rare species are often hindered by the lack of data needed for their effective design. Incomplete and inaccurate data on habitat associations and current species distributions pose a barrier to effective conservation and management for several species of endemic sea snakes in Western Australia that are though...

No-take marine protected areas (MPAs) are a commonly applied tool to reduce human fishing impacts on marine and coastal ecosystems. However, conservation outcomes of MPAs for mobile and long-lived predators such as sharks are highly variable. Here, we use empirical animal tracking data from 459 individual sharks and baited remote underwater video s...

Background Over the past 15 years, the integration of localised passive telemetry networks into centralised data repositories has greatly enhanced our ability to monitor the presence and movements of highly mobile and migratory species. These large-scale networks are now generating big data, allowing meta-analyses across multiple species, locations...

A request for raw data from the corresponding authors of 771 animal biotelemetry-focused manuscripts, published between 1995 and 2015, highlighted a difference in data sharing practices across researcher career levels. Responses were positive in only 11% of requests made to corresponding authors (CAs) that were senior researchers, while 72% of resp...

Marine snakes represent the most speciose group of marine reptiles and are a significant component of reef and coastal ecosystems in tropical oceans. Research on this group has historically been challenging due to the difficulty in capturing, handling, and keeping these animals for field- and lab-based research. Inexplicable declines in marine snak...

Comparative phylogeography can inform many macroevolutionary questions, such as whether species diversification is limited by rates of geographical population differentiation. We examined the link between population genetic structure and species diversification in the fully aquatic sea snakes (Hydrophiinae) by comparing mitochondrial phylogeography...

Acoustic telemetry is a principle tool for observing aquatic animals, but coverage over large spatial scales remains a challenge. To resolve this, Australia has implemented the Integrated Marine Observing System's Animal Tracking Facility which comprises a continental-scale hydrophone array and coordinated data repository. This national acoustic ne...

Our ability to predict species responses to environmental changes relies on accurate records of animal movement patterns. Continental-scale acoustic telemetry networks are increasingly being established worldwide, producing large volumes of information-rich geospatial data. During the last decade, the Integrated Marine Observing System’s Animal Tra...

Proximity to land and sources of freshwater expose fishes residing on inshore reefs to fluctuating environmental conditions (e.g. high freshwater run-off/low salinity events). However, site attachment in many reef residents, such as reef sharks, could mean that relocation in response to unfavourable environmental conditions may not be feasible. Pas...

Partitioning energy between critical basal functions and activity‐associated behaviours is a primary determinant of animal survival. Consequently, habitat selection is likely to be driven by the efficiency with which resources can be acquired from a heterogeneous energy landscape. Determining how energy partitioning is achieved across temporal and...

Facultative air-breathing fish can persist in hypoxic waters due to their capacity to acquire atmospheric oxygen. Most studies examining responses of air-breathing fish to aquatic hypoxia have occurred under experimental conditions. How air-breathing fish respond to hypoxic conditions in the field has received less attention. Using depth sensor tra...

Sea snakes are an important component of bycatch in commercial and small-scale trawl fisheries in tropical waters and are highly vulnerable to fishing-related mortality. Extensive boat-based surveys were conducted to investigate the assemblage and abundance of sea snakes within a protected shallow coastal bay adjacent to productive trawl fishing gr...

Cutaneous gas exchange allows some air-breathing diving ectotherms to supplement their pulmonary oxygen uptake, which may allow prolongation of dives and an increased capacity to withstand anthropogenic and natural threatening processes that increase submergence times. However, little is known of the interplay between metabolism, bimodal oxygen upt...

Resource selection studies often use analytical techniques that provide information at either a population or an individual level. We applied a Bayesian hierarchical model that simultaneously estimates population- and individual-level habitat selection to explore how varying levels of dietary specialisation affect resource requirements of 2 species...

Link to article: http://nesptropical.edu.au/index.php/round-1-projects/project-3-2/

Natural and anthropogenic changes in the marine environment can strongly influence the biology and behaviour of coastal organisms. Understanding how animals that rely on these habitats respond to environmental change is crucial to inform when management actions should be implemented to mitigate or reduce impacts. Here passive acoustic telemetry was...

Background The study of animal movement and use of space have traditionally focused on horizontal and vertical movements separately. However, this may limit the interpretation of results of such behaviours in a three-dimensional environment. Here we use passive acoustic telemetry to visualise and define the three-dimensional use of space by two spe...

The distributions of three species of sea snake (olive sea snake, Aipysurus laevis; spine-bellied sea snake, Lapemis curtus and ornate sea snake, Hydrophis ocellatus) were estimated over 14 ̊ of latitude within the Great Barrier Reef Marine Park (GBRMP) using data from baited remote underwater video stations (BRUVS). A total of 2471 deployments of...