6 results on '"Greenwell, Claire"'
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2. Liked to death: the impacts of social media and photography on biodiversity.
- Author
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Davis RA, Greenwell C, Davis BJ, and Bateman PW
- Subjects
- Animals, Social Media, Biodiversity, Photography, Conservation of Natural Resources
- Abstract
The advent and everyday prominence of social media has fuelled a rise in nature tourism and photography to share experiences online. This is increasingly resulting in disturbance to natural environments and causing a range of direct and indirect impacts to native species. We highlight the key negative impacts of social media on biodiversity and determine which characteristics predispose some taxa to a greater threat from social media than others. Direct disturbances arising from social media use include behavioural and physiological impacts, such as disruptions to breeding and feeding and increased predation risk. The use of call playback, drones and baiting of animals for photographs also have a range of negative impacts. Other direct impacts include the capture and handling of animals for photographs and damage and trampling to plants. Indirect impacts include the spread of diseases and increased poaching of flora and fauna. We advocate for the instigation of codes of ethics and tighter controls around the use and promotion of flora and fauna on social media. We propose a framework that considers species most at risk from social media activities, especially those that are rare, sessile and have restricted ranges., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
3. Cat Gets Its Tern: A Case Study of Predation on a Threatened Coastal Seabird.
- Author
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Greenwell CN, Calver MC, and Loneragan NR
- Abstract
Domestic cats have a cosmopolitan distribution, commonly residing in urban, suburban and peri-urban environments that are also critical for biodiversity conservation. This study describes the impact of a desexed, free-roaming cat on the behavior of a threatened coastal seabird, the Australian Fairy Tern, Sternula nereis nereis , in Mandurah, south-western Australia. Wildlife cameras and direct observations of cat incursions into the tern colony at night, decapitated carcasses of adult terns, dead, injured or missing tern chicks, and cat tracks and scats around the colony provided strong evidence of cat predation, which led to an initial change in nesting behavior and, ultimately, colony abandonment and the reproductive failure of 111 nests. The death of six breeding terns from the population was a considerable loss for this threatened species and had the potential to limit population growth. This study highlights the significant negative impacts of free-roaming cats on wildlife and the need for monitoring and controlling cats at sites managed for species conservation. It also provides strong evidence against the practice of trap-neuter-release programs and demonstrates that desexed cats can continue to negatively impact wildlife post-release directly through predation, but also indirectly through fundamental changes in prey behavior and a reduction in parental care.
- Published
- 2019
- Full Text
- View/download PDF
4. Regional differences in the feeding of the ambush predator Neosebastes pandus and comparisons of diets in the Scorpaenidae, Triglidae and Platycephalidae.
- Author
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Greenwell CN, Coulson PG, Tweedley JR, and Loneragan NR
- Subjects
- Animals, Body Size, Ecosystem, Feeding Behavior, Fishes, Gastrointestinal Contents, Predatory Behavior, Seasons, Western Australia, Diet, Perciformes
- Abstract
This study provides a comprehensive assessment of the dietary composition of the ambush predator Neosebastes pandus and compares the diets of 49 species from 39 studies of three benthic predatory families in the Scorpaeniformes: Scorpaenidae (20 species), Triglidae (19 species) and Platycephalidae (10 species). A total of 275 N. pandus were collected from the west (Rottnest Island) and south (Esperance) coasts of south-western Australia and the percentage frequency and volumetric contribution of the stomach contents identified. Fish from the west coast consumed a greater mean number of broad taxonomic groups and were more diverse in their diet than fish from the south coast. Cephalopods, brachyurans and teleosts were the largest overall contributors to diet, with teleosts being more important to diets of west-coast fish and polychaetes for south-coast fish. This reflects differences in habitat between the two locations. Dietary composition also changed with increasing body size, reflecting morphological changes that allow bigger fish to capture and ingest larger, more mobile prey. Meta-analysis of the diets of 49 species of scorpaenid, triglid and platycephalid revealed that they feed predominantly on teleosts and large crustaceans. Significant differences in diet were detected among families, with platycephalids being the most distinct and feeding more on teleosts than scorpaenids and triglids., (© 2018 The Fisheries Society of the British Isles.)
- Published
- 2018
- Full Text
- View/download PDF
5. Direct Reflectance Measurements from Drones: Sensor Absolute Radiometric Calibration and System Tests for Forest Reflectance Characterization.
- Author
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Hakala T, Markelin L, Honkavaara E, Scott B, Theocharous T, Nevalainen O, Näsi R, Suomalainen J, Viljanen N, Greenwell C, and Fox N
- Abstract
Drone-based remote sensing has evolved rapidly in recent years. Miniaturized hyperspectral imaging sensors are becoming more common as they provide more abundant information of the object compared to traditional cameras. Reflectance is a physically defined object property and therefore often preferred output of the remote sensing data capture to be used in the further processes. Absolute calibration of the sensor provides a possibility for physical modelling of the imaging process and enables efficient procedures for reflectance correction. Our objective is to develop a method for direct reflectance measurements for drone-based remote sensing. It is based on an imaging spectrometer and irradiance spectrometer. This approach is highly attractive for many practical applications as it does not require in situ reflectance panels for converting the sensor radiance to ground reflectance factors. We performed SI-traceable spectral and radiance calibration of a tuneable Fabry-Pérot Interferometer -based (FPI) hyperspectral camera at the National Physical Laboratory NPL (Teddington, UK). The camera represents novel technology by collecting 2D format hyperspectral image cubes using time sequential spectral scanning principle. The radiance accuracy of different channels varied between ±4% when evaluated using independent test data, and linearity of the camera response was on average 0.9994. The spectral response calibration showed side peaks on several channels that were due to the multiple orders of interference of the FPI. The drone-based direct reflectance measurement system showed promising results with imagery collected over Wytham Forest (Oxford, UK)., Competing Interests: The authors declare no conflict of interest.
- Published
- 2018
- Full Text
- View/download PDF
6. Spectral radiance source based on supercontinuum laser and wavelength tunable bandpass filter: the spectrally tunable absolute irradiance and radiance source.
- Author
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Levick AP, Greenwell CL, Ireland J, Woolliams ER, Goodman TM, Bialek A, and Fox NP
- Abstract
A new spectrally tunable source for calibration of radiometric detectors in radiance, irradiance, or power mode has been developed and characterized. It is termed the spectrally tunable absolute irradiance and radiance source (STAIRS). It consists of a supercontinuum laser, wavelength tunable bandpass filter, power stabilization feedback control scheme, and output coupling optics. It has the advantages of relative portability and a collimated beam (low étendue), and is an alternative to conventional sources such as tungsten lamps, blackbodies, or tunable lasers. The supercontinuum laser is a commercial Fianium SC400-6-02, which has a wavelength range between 400 and 2500 nm and a total power of 6 W. The wavelength tunable bandpass filter, a PhotonEtc laser line tunable filter (LLTF), is tunable between 400 and 1000 nm and has a bandwidth of 1 or 2 nm depending on the wavelength selected. The collimated laser beam from the LLTF filter is converted to an appropriate spatial and angular distribution for the application considered (i.e., for radiance, irradiance, or power mode calibration of a radiometric sensor) with the output coupling optics, for example, an integrating sphere, and the spectral radiance/irradiance/power of the source is measured using a calibration optical sensor. A power stabilization feedback control scheme has been incorporated that stabilizes the source to better than 0.01% for averaging times longer than 100 s. The out-of-band transmission of the LLTF filter is estimated to be < -65 dB (0.00003%), and is sufficiently low for many end-user applications, for example the spectral radiance calibration of earth observation imaging radiometers and the stray light characterization of array spectrometers (the end-user optical sensor). We have made initial measurements of two end-user instruments with the STAIRS source, an array spectrometer and ocean color radiometer.
- Published
- 2014
- Full Text
- View/download PDF
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