Ellie Owen

National Trust for Scotland | NTS

The distribution of marine predators is linked to bio-physical processes that structure the spatio-temporal availability of prey species. Within shelf seas, tidal fronts are highly productive regions occurring at the interface between mixed and stratified waters. Fronts are predictable but dynamic features, with their timing and strength varying se...

Understanding an animal's diet is a crucial component of conservation, but diet data are often labor intensive to collect and are frequently scarce. Atlantic Puffins (Fratercula arctica; hereafter Puffins) are vulnerable to global extinction and have declined in some parts of their UK and Irish range. Differences in population trajectories may rela...

Developing standardized methodology to allow efficient and cost-effective ecological data collection, particularly at scale, is of critical importance for understanding species' declines. Remote camera networks can enable monitoring across large spatiotemporal scales and at relatively low researcher cost, but manually analysing images and extractin...

Knowledge of seabird distributions plays a key role in seabird conservation and sustainable marine management, underpinning efforts to designate protected areas or assess the impact of human developments. Technological advances in animal tracking devices increasingly allow researchers to acquire information on the movement of birds from specific co...

Plastic pollution is distributed patchily around the world’s oceans. Likewise, marine organisms that are vulnerable to plastic ingestion or entanglement have uneven distributions. Understanding where wildlife encounters plastic is crucial for targeting research and mitigation. Oceanic seabirds, particularly petrels, frequently ingest plastic, are h...

Animal tracking has afforded insights into patterns of space use in numerous species and thereby informed area-based conservation planning. A crucial consideration when estimating spatial distributions from tracking data is whether the sample of tracked animals is representative of the wider population. However, it may also be important to track an...

Density-dependent prey depletion around breeding colonies has long been considered an important factor controlling the population dynamics of colonial animals.1, 2, 3, 4 Ashmole proposed that as seabird colony size increases, intraspecific competition leads to declines in reproductive success, as breeding adults must spend more time and energy to f...

Habitat-use and distribution models are essential tools of conservation biology. For wide-ranging species, such models may be challenged by the expanse, remoteness and variability of their habitat, these challenges often being compounded by the species’ mobility. In marine environments, direct observations and sampling are usually impractical over...

Individual specialisations in behaviour are predicted to arise where divergence benefits fitness. Such specialisations are more likely in heterogeneous environments where there is both greater ecological opportunity and competition‐driven frequency dependent selection. Such an effect could explain observed differences in rates of individual special...

Bycatch of seabirds in gillnet fisheries is a global conservation issue with an estimated 400 000 seabirds killed each year. To date, no underwater deterrents trialled have consistently reduced seabird bycatch across operational fisheries. Using a combination of insights from land-based strategies, seabirds' diving behaviours and their cognitive ab...

The use of bio‐logging devices to track animal movement continues to grow as technological advances and device miniaturisation allow researchers to study animal behaviour in unprecedented detail. Balanced against the remarkable data that bio‐loggers can provide is a need to understand the impact of devices on animal behaviour and welfare. Recent me...

The growth of the marine renewable energy sector requires the potential effects on marine wildlife to be considered carefully. For this purpose, utilization distributions derived from animal-borne biologging and telemetry data provide accurate information on individual space use. The degree of spatial overlap between potentially vulnerable wildlife...

Incidental mortality (bycatch) in fisheries represents a threat to marine vertebrates. Research has predominantly focussed on bycatch in longline fisheries, but bycatch from gillnet fisheries is of increasing concern. To address this concern, we combined comprehensive biologging data sets and multiple sources of fishing effort data to assess the sp...

Marine protected areas (MPAs) underpin the sustainable management of marine ecosystems but require accurate knowledge of species distributions. Recently, advances in tracking technology and habitat modelling have enabled the production of large-scale species distribution models (SDM), which provide the basis for hotspot mapping. In the UK, hotspot...

Mapping the distribution of seabirds at sea is fundamental to understanding their ecology and making informed decisions on their conservation. Until recently, estimates of at-sea distributions were generally derived from boat-based visual surveys. Increasingly however, seabird tracking is seen as an alternative but each has potential biases. To com...

Environmental heterogeneity shapes the uneven distribution of resources available to foragers, and is ubiquitous in nature. Optimal foraging theory predicts that an animal's ability to exploit resource patches is key to foraging success. However, the potential fitness costs and benefits of foraging in a heterogeneous environment are difficult to me...

Small global positioning system (GPS) trackers are now routinely used to study the movement and behaviour of birds at sea. If the birds rest on the water they become “drifters of opportunity” and can be used to give information about surface currents. In this paper, we use a small data set from satellite-tracked razorbills (Alca torda) in the Irish...

Knowing the spatial scales at which effective management can be implemented is fundamental for conservation planning. This is especially important for mobile species, which can be exposed to threats across large areas, but the space use requirements of different species can vary to an extent that might render some management approaches inefficient....

Knowing the spatial scales at which effective management can be implemented is fundamental for conservation planning. This is especially important for mobile species, which can be exposed to threats across large areas, but the space use requirements of different species can vary to an extent that might render some management approaches inefficient....

Scottish Birds: Journal of the Scottish Ornithologists' Club

Processing telemetry data via species distribution models for hotspot analysis • Review and comparison of different hotspot mapping techniques • Creation of hotspot maps for four seabird species at multiple spatial scales https://www.rspb.org.uk/globalassets/downloads/documents/conservation-science/cleasby_owen_wilson_bolton_2018.pdf

Small GPS trackers are now routinely used to study the movement and behaviour of birds at sea. If the birds rest on the water they become drifters of opportunity and can be used to give information about surface currents. In this paper, we use a small data set from satellite-tracked razorbills (Alca torda) in the Irish Sea to test the potential of...

Atlantic Puffins Fratercula arctica were counted at all known colonies in Orkney (excluding Sule Skerry) during the 2016 breeding season. Counts of individuals (IND) were made during pre-laying and incubation at all 20 sites and at six sites where burrows where physically accessible. In 2016 the Atlantic Puffin population of Orkney was estimated to...

To prevent further global declines in biodiversity, identifying and understanding key habitats is crucial for successful conservation strategies. For example, globally, seabird populations are under threat and animal movement data can identify key at‐sea areas and provide valuable information on the state of marine ecosystems. To date, in order to...

Detailed information acquired using tracking technology has the potential to provide accurate pictures of the types of movements and behaviors performed by animals. To date, such data have not been widely exploited to provide inferred information about the foraging habitat. We collected data using multiple sensors (GPS, time depth recorders, and ac...

Population-level estimates of species' distributions can reveal fundamental ecological processes and facilitate conservation. However, these may be difficult to obtain for mobile species, especially colonial central-place foragers (CCPFs; e.g. bats, corvids, social insects), because it is often impractical to determine the provenance of individuals...

• In the North Sea, sandeels provide a vital food source for breeding seabirds, but are also the target of an industrial fishery. GPS tracking suggests that the most productive fishing grounds overlap with foraging areas of black‐legged kittiwakes from eastern England, raising the prospect that the fishery could affect the birds. Rising sea tempera...

Andrew Motion uses interviews with scientists and environmentalists to form the basis of a new series of poems that address the subject of climate change. http://www.bbc.co.uk/programmes/b082l8m3

Satellite tracking data collected by The Royal Society for the Protection of Birds from tagged seabirds sitting on the water has revealed the potential for using this data to predict information about tidal current amplitude around the North coast of Anglesey, North Wales. Here we present a method by which these Lagrangian datasets can be used to p...

Recent international initiatives have promoted a number of different approaches to identify marine Important Bird and biodiversity Areas (IBAs), which are important areas for foraging, migrating or over-wintering seabirds. The ‘Foraging Radius Approach’ is one of these and uses known foraging range and habitat preferences to predict the size and lo...

In order to maximize foraging efficiency in a varying environment, predators are expected to optimize their search strategy. Environmental conditions are one important factor affecting these movement patterns, but variations in breeding constraints (self-feeding vs. feeding young and self-feeding) during different breeding stages (incubation vs. ch...

The recent increase in data accuracy from high resolution accelerometers offers substantial potential for improved understanding and prediction of animal movements. However, current approaches used for analysing these multivariable datasets typically require existing knowledge of the behaviors of the animals to inform the behavioral classification...

Table S1. Transition probability matrix of the behavioural states classified in the 5 razorbills. Table S2. Transition probability matrix of the behavioural states classified in the 2 guillemots.

Data S1. Example of the latent behavioural classes' recognition performed in COGU_1 and COGU_2 underwater.

Data S2. Example of the latent behavioural classes' recognition performed in RAZO_3.

Data S3. R code used for the analysis of the accelerometer data.

Whilst the legal framework for establishment of offshore Marine Protected Areas (MPAs) for seabirds in the European Union has existed for many decades, progress on designation of such areas has been slow, largely as a result of an inadequate evidence base upon which to identify qualifying areas. The recent increase in seabird tracking studies has s...

The black-legged kittiwake (Rissa tridactyla) is one of the UK's most abundant seabirds but the population has declined by 60% since the 1980s. Declines have been linked to rising sea surface temperatures (SSTs) that are believed to affect recruitment and growth of the lesser sandeel (Ammodytes marinus), a key kittiwake prey species, in turn causin...

Diving seabirds respond to complex environmental heterogeneity at multiple scales to maximize overlap with prey, making decisions about where and when to search for resources. The circumstances in which seabirds capture of prey underwater are largely unknown, as are the search strategies used in successful and efficient foraging events. Acceleromet...

Diving seabirds move and forage in complex marine environments. The combination of their movements, physiological constrains, energy budgets and the characteristics of the environment, shapes different foraging strategies between species. The development of new technologies, the miniaturisation of electronic components and the creation of 3-D model...

As apex predators in marine ecosystems, seabirds may primarily experience climate change impacts indirectly, via changes to their food webs. Observed seabird population declines have been linked to climate-driven oceanographic and food web changes. However, relationships have often been derived from relatively few colonies and consider only sea sur...

Developments in tracking technologies have enhanced our understanding of the behaviours of many seabird species. However few studies have examined the social aspects of seabird foraging behaviour, despite the effect this might have on the distribution of foraging areas and the differences that might arise between colonies. Here we use bird-borne GP...

Many established models of animal foraging assume that individuals are ecologically equivalent. However, it is increasingly recognized that some populations comprise animals whose diet or foraging behaviours differ consistently among individuals. For example, recent studies have shown that individual foraging site fidelity (IFSF), when individuals...

As marine renewable energy applications are increasing in the UK, environmental and cumulative impacts and their assessments are receiving considerable attention. The uncertainty, particularly surrounding cumulative impacts, however remains high and is becoming a cause of delay in the consenting process. This study examines the sources of uncertain...

How central-place foragers change search strategy in response to environmental conditions is poorly known. Foragers may vary the total distance travelled and how far they range from the central place in response to variation in the distribution of their prey. One potential reason as to why they would extend the length of their foraging trip and its...

Cumulative impacts and their assessments are receiving more attention in the UK as marine renewable energy applications are increasing with an unprecedented industrialisation of the marine environment. The uncertainty surrounding cumulative impacts however remains high and is becoming a cause of delay in the consenting process. Using the example of...

A key challenge in ecology is to find ways to obtain complete and accurate information about the diets of animals. To respond to this challenge in seabirds, traditional methods (usually stomach content analysis or observations of prey at nests) have been supplemented with indirect methods or molecular trophic markers. These techniques have the pote...

Adipose tissue samples can provide valuable information about the physiology, foraging ecology, and toxicology of birds. However, despite these varied applications, to date, no procedure for taking adipose samples from live birds has been described in detail, nor assessed for potential adverse effects. We describe a nonlethal method for collecting...