Vinay Udyawer

Antipredator tactics: a kin‐selection benefit for defensive spines in coral catfish?

Publisher: Wiley

Date: 10-11-2020

DOI: 10.1111/OIK.07838

A standardised framework for analysing animal detections from automated tracking arrays

Publisher: Springer Science and Business Media LLC

Date: 12-2018

DOI: 10.1186/S40317-018-0162-2

Coming up for air: thermal dependence of dive behaviours and metabolism in sea snakes.

Publisher: The Company of Biologists

Date: 2016

DOI: 10.1242/JEB.146571

Abstract: Cutaneous gas exchange allows some air-breathing ing ectotherms to supplement their pulmonary oxygen uptake, which may allow prolongation of es 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 uptake and activity levels across thermal environments in ing ectotherms. Here, we show in two species of sea snake (spine-bellied sea snake, Hydrophis curtus and elegant sea snake, Hydrophis elegans) that increasing temperature elevates surfacing rate, increases total oxygen consumption and decreases e duration. The majority of es observed in both species remained within estimated maximal aerobic limits. While cutaneous gas exchange accounted for a substantial proportion of total oxygen consumption (up to 23%), unexpectedly it was independent of water temperature and activity levels, suggesting a diffusion-limited mechanism. Our findings demonstrate that rising water temperature and a limited capability to up-regulate cutaneous oxygen uptake may compromise the proficiency with which sea snakes perform prolonged es. This may hinder their capacity to withstand ongoing anthropogenic activities like trawl fishing, and increase their susceptibility to surface predation as their natural environments continue to warm.

Multi-year effects of wildlife tourism on shark residency and implications for management

Publisher: Elsevier BV

Date: 2023

DOI: 10.1016/J.MARPOL.2022.105362

Widespread diversity deficits of coral reef sharks and rays

Publisher: American Association for the Advancement of Science (AAAS)

Date: 16-06-2023

DOI: 10.1126/SCIENCE.ADE4884

Abstract: A global survey of coral reefs reveals that overfishing is driving resident shark species toward extinction, causing ersity 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 in idual shark species were not detected at 34 to 47% of surveyed reefs. As reefs become more shark-depleted, rays begin to dominate assemblages. Shark-dominated assemblages persist in wealthy nations with strong governance and in highly protected areas, whereas poverty, weak governance, and a lack of shark management are associated with depauperate assemblages mainly composed of rays. Without action to address these ersity deficits, loss of ecological function and ecosystem services will increasingly affect human communities.

Temporal and spatial activity‐associated energy partitioning in free‐swimming sea snakes

Publisher: Wiley

Date: 15-05-2017

DOI: 10.1111/1365-2435.12882

Coordinated and communal hunting behaviours by Erabu sea krait Laticauda semifactiata

Publisher: Authorea, Inc.

Date: 13-02-2023

DOI: 10.22541/AU.167631322.24665235/V1

Abstract: 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 hunting party to encounter and capture prey in these complex habitats. Here we recorded 52 instances of communal hunting by Erabu sea snakes with conspecifics and other predatory fishes at recreational e sites in Southern Lombok, Indonesia. These observations highlight the potential higher cognitive capacity of sea snakes to coordinate activities around communal hunting events.

Individual and Population Benefits of Marine Reserves for Reef Sharks

Publisher: Elsevier BV

Date: 02-2020

DOI: 10.1016/J.CUB.2019.12.005

Abstract: 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 in idual sharks and baited remote underwater video surveys undertaken in 36 countries to construct an empirically supported in idual-based model that estimates the conservation effectiveness of MPAs for five species of coral reef-associated sharks (Triaenodon obesus, Carcharhinus melanopterus, Carcharhinus amblyrhynchos, Carcharhinus perezi, and Ginglymostoma cirratum). We demonstrate how species-specific in idual movement traits can contribute to fishing mortality of sharks found within MPAs as they move outside to adjacent fishing grounds. We discovered that the world's officially recorded coral reef-based managed areas (with a median width of 9.4 km) would need to be enforced as strict no-take MPAs and up to 5 times larger to expect protection of the majority of in iduals of the five investigated reef shark species. The magnitude of this effect depended on local abundances and fishing pressure, with MPAs required to be 1.6-2.6 times larger to protect the same number of Atlantic and Caribbean species, which occur at lower abundances than similar species in the western Pacific. Furthermore, our model was used to quantify partially substantial reductions (>50%) in fishing mortality resulting from small increases in MPA size, allowing us to bridge a critical gap between traditional conservation planning and fisheries management. Overall, our results highlight the challenge of relying on abundance data alone to ensure that estimates of shark conservation impacts of MPAs follow the precautionary approach.

Long-distance movements of free-ranging sea snakes (Hydrophis, Elapidae)

Publisher: Springer Science and Business Media LLC

Date: 28-07-2023

DOI: 10.1007/S00338-023-02408-1

Prioritising search effort to locate previously unknown populations of endangered marine reptiles

Publisher: Elsevier BV

Date: 06-2020

DOI: 10.1016/J.GECCO.2020.E01013

Peaceful coexistence between people and deadly wildlife: Why are recreational users of the ocean so rarely bitten by sea snakes?

Publisher: Wiley

Date: 11-05-2011

DOI: 10.1002/PAN3.10190

A review of the life history and ecology of euryhaline and estuarine sharks and rays

Publisher: Springer Science and Business Media LLC

Date: 23-10-2023

DOI: 10.1007/S11160-023-09807-1

The southern cassowary (Casuarius casuarius johnsonii) remains an important disperser of native plants in fragmented rainforest landscapes

Publisher: Wiley

Date: 21-03-2015

DOI: 10.1111/AEC.13309

Abstract: 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 fragmented, and exotic fruits are abundant. To do this, we developed a tri‐axial acceleration logger integrated with a motion sensor and VHF radio transmitter. The telemetry device was small enough to be hidden inside a native fruit. The cassowaries ingested it, transported it and defecated it up to 24 h later with the seeds from the fruits they had ingested during the tracking period. The telemetry device was then located by VHF radio and collected with the scat. The distance travelled, activity profile, consumed fruit ersity, and scat energy content were assessed for cassowaries inhabiting regions with different degrees of urbanization. We found that cassowaries inhabiting more urbanized areas consumed the greatest proportion of fruits from exotic plants (~30%) but still incorporated a significant proportion of fruits from native plants in their diet. These in iduals existed in higher states of activity and rested less than in iduals inhabiting more intact swathes of rainforest, actively moving between urban gardens and the rainforest. The study shows cassowaries have a flexible foraging strategy that has enabled them to persist in rainforest‐fragmented landscapes. They remain a significant disperser of seeds from native plants between rainforest patches, and as such, cassowaries remain essential in maintaining native plant ersity within these fragmented patches.

Continental-scale animal tracking reveals functional movement classes across marine taxa

Publisher: Springer Science and Business Media LLC

Date: 27-02-2018

DOI: 10.1038/S41598-018-21988-5

Abstract: 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 network connects localized projects, enabling simultaneous monitoring of multiple species over scales ranging from 100 s of meters to 1000 s of kilometers. There is a need to evaluate the utility of this national network in monitoring animal movement ecology, and to identify the spatial scales that the network effectively operates over. Cluster analyses assessed movements and residency of 2181 in iduals from 92 species, and identified four functional movement classes apparent only through aggregating data across the entire national network. These functional movement classes described movement metrics of in iduals rather than species, and highlighted the plasticity of movement patterns across and within populations and species. Network analyses assessed the utility and redundancy of each component of the national network, revealing multiple spatial scales of connectivity influenced by the geographic positioning of acoustic receivers. We demonstrate the significance of this nationally coordinated network of receivers to better reveal intra-specific differences in movement profiles and discuss implications for effective management.

Dietary shifts may underpin the recovery of a large carnivore population

Publisher: The Royal Society

Date: 04-2022

DOI: 10.1098/RSBL.2021.0676

Abstract: 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 isotopes δ 13 C and δ 15 N in bones of crocodiles s led 40 to 55 years ago (small population) with bones from contemporary in iduals (large population). We found that δ 13 C and δ 15 N values were significantly lower in contemporary crocodiles than in the historical cohort, inferring a shift in prey preference away from marine and into terrestrial food webs. We propose that an increase in intraspecific competition within the recovering crocodile population, alongside an increased abundance of feral ungulates occupying the floodplains, may have resulted in the crocodile population shifting to feed predominantly upon terrestrial food sources. The number of feral pigs consumed to sustain and grow crocodile biomass may help suppress pig population growth and increase the flow of terrestrially derived nutrients into aquatic ecosystems. The study highlights the significance of prey availability in contributing to large carnivore population recovery.

Rates of population differentiation and speciation are decoupled in sea snakes

Publisher: The Royal Society

Date: 10-2018

DOI: 10.1098/RSBL.2018.0563

Abstract: Comparative phylogeography can inform many macroevolutionary questions, such as whether species ersification is limited by rates of geographical population differentiation. We examined the link between population genetic structure and species ersification in the fully aquatic sea snakes (Hydrophiinae) by comparing mitochondrial phylogeography across northern Australia in 16 species from two closely related clades that show contrasting ersification dynamics. Contrary to expectations from theory and several empirical studies, our results show that, at the geographical scale studied here, rates of population differentiation and speciation are not positively linked in sea snakes. The eight species s led from the rapidly speciating Hydrophis clade have weak population differentiation that lacks geographical structure. By contrast, all eight s led Aipysurus–Emydocephalus species show clear geographical patterns and many deep intraspecific splits, but have threefold slower speciation rates. Alternative factors, such as ecological specialization, species duration and geographical range size, may underlie rapid speciation in sea snakes.

Massey University

Location: New Zealand

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James Cook University

Location: Australia

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Australian Institute Of Marine Science

Location: Australia

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Linkage Projects - Grant ID: LP200100222

Start Date: 03-2021

End Date: 03-2024

Amount: $535,200.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP210103369

Start Date: 10-2021

End Date: 09-2024

Amount: $391,000.00

Funder: Australian Research Council