182 research outputs found
Studying seabird diet through genetic analysis of faeces: a case study on Macaroni Penguins (Eudyptes chrysolophus)
Determination of seabird diet usually relies on the analysis of stomach-content remains obtained through stomach flushing; this technique is both invasive and logistically difficult. We evaluate the usefulness of DNA-based faecal analysis in a dietary study on chick-rearing macaroni penguins (Eudyptes chrysolophus) at Heard Island. Conventional stomach-content data was also collected, allowing comparison of the approaches. Methodology/Principal Findings. Preyspecific PCR tests were used to detect dietary DNA in faecal samples and amplified prey DNA was cloned and sequenced. Of the 88 faecal samples collected, 39 contained detectable DNA from one or more of the prey groups targeted with PCR tests. Euphausiid DNA was most commonly detected in the early (guard) stage of chick-rearing, and detection of DNA from the myctophid fish Krefftichthys anderssoni and amphipods became more common in samples collected in the later (cre`che) stage. These trends followed those observed in the penguins’ stomach contents. In euphausiid-specific clone libraries the proportion of sequences from the two dominant euphausiid prey species (Euphausia vallentini and Thysanoessa macrura) changed over the sampling period; again, this reflected the trend in the stomach content data. Analysis of prey sequences in universal clone libraries revealed a higher diversity of fish prey than identified in the stomachs, but non-fish prey were not well represented. Conclusions/Significance. The present study is one of the first to examine the full breadth of a predator’s diet using DNA based faecal analysis. We discuss methodological difficulties encountered and suggest possible refinements. Overall, the ability of the DNA-based approach to detect temporal variation in the diet of macaroni penguins indicates this non-invasive method will be generally useful for monitoring population-level dietary trends in seabirds
Deep learning resolves representative movement patterns in a marine predator species
The analysis of animal movement from telemetry data provides insights into how and why animals move. While traditional approaches to such analysis mostly focus on predicting animal states during movement, we describe an approach that allows us to identify representative movement patterns of different animal groups. To do this, we propose a carefully designed recurrent neural network and combine it with telemetry data for automatic feature extraction and identification of non-predefined representative patterns. In the experiment, we consider a particular marine predator species, the southern elephant seal, as an example. With our approach, we identify that the male seals in our data set share similar movement patterns when they are close to land. We identify this pattern recurring in a number of distant locations, consistent with alternative approaches from previous research
(Re)imagining the ‘backstreet’:Anti-abortion campaigning against decriminalisation in the UK
The risk of death or serious injury from ‘backstreet abortions’ was an important narrative in the 20th century campaign to liberalise abortion in the UK. Since then, clinical developments have reduced the overall health risks of abortion, and international health organisations have been set up to provide cross-border, medically safe abortions to places where it is unlawful, offering advice and, where possible, supplying abortion pills. These changes mean that pro-choice campaigns in Europe have often moved away from the risks of ‘backstreet abortions’ as a central narrative when campaigning for abortion liberalisation. In contrast, in the UK, anti-abortion activists are increasingly using ideas about ‘backstreet abortions’ to resist further liberalisation. These claims can be seen to fit within a broader shift from morals to risk within moral regulation campaigns and build on anti-abortion messages framed as being ‘pro-women’, with anti-abortion activists claiming to be the ‘savers’ of women. Using a parliamentary debate as a case study, this article will illustrate these trends and show how the ‘backstreet’ metaphor within anti-abortion campaigns builds on three interconnected themes of ‘abortion-as-harmful’, ‘abortion industry’, and ‘abortion culture’. This article will argue that the anti-abortion movement’s adoption of risk-based narratives contains unresolved contradictions due to the underlying moral basis of their position. These are exacerbated by the need, in this case, to defend legislation that they fundamentally disagree with. Moreover, their attempts to construct identifiable ‘harms’ and vulnerable ‘victims’, which are components of moral regulation campaigns, are unlikely to be convincing in the context of widespread public support for abortion
'On the Wet Side of the Womb’:The construction of mothers in anti-abortion activism in England and Wales
Across the UK, there has been an increase in anti-abortion activism outside abortion clinics. The activism deployed includes explicitly religious activities such as ‘prayerful witnessing’ and ‘pavement counselling’, which aim to discourage women from entering clinics. This article stems from a wider ethnographic study of public activism over abortion to determine what claims about motherhood are being made within these debates. Two arguments are presented. First, how women’s role as mothers is central and essentialised in anti-abortion discourses, with the body of the mother often disappearing as activists seek to erode the distinction between a foetus and a baby by constructing pregnancy as a foetal environment. Motherhood is constructed as ‘natural’ and sacred, therefore abortion must be damaging because it destroys women’s ‘natural’ position. Second, the article argues that although the activists’ arguments are always religiously framed, their activism takes place in a largely secular context, meaning that they have to find ways of appealing to secular audiences. This leads to a complex interrelationship between secular and religious discourses, where theological viewpoints sit alongside ‘scientific’ claims to buttress activists’ views. This article explores how the presence and absence of mothers within activists’ narratives is due to the tensions between religiously based understandings of motherhood, and the need to appeal to a secular audience
A standardisation framework for bio‐logging data to advance ecological research and conservation
Bio‐logging data obtained by tagging animals are key to addressing global conservation challenges. However, the many thousands of existing bio‐logging datasets are not easily discoverable, universally comparable, nor readily accessible through existing repositories and across platforms, slowing down ecological research and effective management. A set of universal standards is needed to ensure discoverability, interoperability and effective translation of bio‐logging data into research and management recommendations.
We propose a standardisation framework adhering to existing data principles (FAIR: Findable, Accessible, Interoperable and Reusable; and TRUST: Transparency, Responsibility, User focus, Sustainability and Technology) and involving the use of simple templates to create a data flow from manufacturers and researchers to compliant repositories, where automated procedures should be in place to prepare data availability into four standardised levels: (a) decoded raw data, (b) curated data, (c) interpolated data and (d) gridded data. Our framework allows for integration of simple tabular arrays (e.g. csv files) and creation of sharable and interoperable network Common Data Form (netCDF) files containing all the needed information for accuracy‐of‐use, rightful attribution (ensuring data providers keep ownership through the entire process) and data preservation security.
We show the standardisation benefits for all stakeholders involved, and illustrate the application of our framework by focusing on marine animals and by providing examples of the workflow across all data levels, including filled templates and code to process data between levels, as well as templates to prepare netCDF files ready for sharing.
Adoption of our framework will facilitate collection of Essential Ocean Variables (EOVs) in support of the Global Ocean Observing System (GOOS) and inter‐governmental assessments (e.g. the World Ocean Assessment), and will provide a starting point for broader efforts to establish interoperable bio‐logging data formats across all fields in animal ecology
Phocid Seal Leptin: Tertiary Structure and Hydrophobic Receptor Binding Site Preservation during Distinct Leptin Gene Evolution
The cytokine hormone leptin is a key signalling molecule in many pathways that control physiological functions. Although leptin demonstrates structural conservation in mammals, there is evidence of positive selection in primates, lagomorphs and chiropterans. We previously reported that the leptin genes of the grey and harbour seals (phocids) have significantly diverged from other mammals. Therefore we further investigated the diversification of leptin in phocids, other marine mammals and terrestrial taxa by sequencing the leptin genes of representative species. Phylogenetic reconstruction revealed that leptin diversification was pronounced within the phocid seals with a high dN/dS ratio of 2.8, indicating positive selection. We found significant evidence of positive selection along the branch leading to the phocids, within the phocid clade, but not over the dataset as a whole. Structural predictions indicate that the individual residues under selection are away from the leptin receptor (LEPR) binding site. Predictions of the surface electrostatic potential indicate that phocid seal leptin is notably different to other mammalian leptins, including the otariids. Cloning the grey seal leptin binding domain of LEPR confirmed that this was structurally conserved. These data, viewed in toto, support a hypothesis that phocid leptin divergence is unlikely to have arisen by random mutation. Based upon these phylogenetic and structural assessments, and considering the comparative physiology and varying life histories among species, we postulate that the unique phocid diving behaviour has produced this selection pressure. The Phocidae includes some of the deepest diving species, yet have the least modified lung structure to cope with pressure and volume changes experienced at depth. Therefore, greater surfactant production is required to facilitate rapid lung re-inflation upon surfacing, while maintaining patent airways. We suggest that this additional surfactant requirement is met by the leptin pulmonary surfactant production pathway which normally appears only to function in the mammalian foetus
Cephalopoda as prey of juvenile Southern elephant seals at Isla 25 de Mayo/King George, South Shetland Islands
Convergence of marine megafauna movement patterns in coastal and open oceans
The extent of increasing anthropogenic impacts on large marine vertebrates partly depends on the animals’ movement patterns. Effective conservation requires identification of the key drivers of movement including intrinsic properties and extrinsic constraints associated with the dynamic nature of the environments the animals inhabit. However, the relative importance of intrinsic versus extrinsic factors remains elusive. We analyze a global dataset of ∼2.8 million locations from >2,600 tracked individuals across 50 marine vertebrates evolutionarily separated by millions of years and using different locomotion modes (fly, swim, walk/paddle). Strikingly, movement patterns show a remarkable convergence, being strongly conserved across species and independent of body length and mass, despite these traits ranging over 10 orders of magnitude among the species studied. This represents a fundamental difference between marine and terrestrial vertebrates not previously identified, likely linked to the reduced costs of locomotion in water. Movement patterns were primarily explained by the interaction between species-specific traits and the habitat(s) they move through, resulting in complex movement patterns when moving close to coasts compared with more predictable patterns when moving in open oceans. This distinct difference may be associated with greater complexity within coastal microhabitats, highlighting a critical role of preferred habitat in shaping marine vertebrate global movements. Efforts to develop understanding of the characteristics of vertebrate movement should consider the habitat(s) through which they move to identify how movement patterns will alter with forecasted severe ocean changes, such as reduced Arctic sea ice cover, sea level rise, and declining oxygen content
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