Alpine ungulate movement: Quantification of spatiotemporal environmental energetics and social interaction

Species movement, an animal’s ability to change its location, is a fundamental property of life, and animals have diverse physical and behavioural attributes that are believed to enhance efficient travel and optimization of resources. Quantifying movement energetics and returns to examine these ideas over relevant time- and space scales is, however, problematic. In this thesis, I set out to develop and use advanced biologging tag technology to determine a second by second account of the behaviour and location of tagged animals to unveil where and when key behaviours are occurring, to answer key questions about feeding and social behaviour, allocation in space and the energetic costs associated with different movement decisions. Specifically, I used accelerometers, magnetometers, temperature and pressure sensors with GPS units in animal-attached loggers to examine key questions linking movement, energetics and feeding and aggressive behaviours in 3 wild- and 3 domestic ungulate species in mountainous landscapes in the French Alps, monitored for periods between 30 and 200 days. To obtain high-frequency data using electronic devices for long periods, I had to first design new housings to attach safely the loggers to the animals and develop methods for weather proofing the loggers. I designed, using CAD-designa and 3D printing, different housing types and used ‘Guronic’ resin to shockproof and waterproof circuit boards. This allowed me to obtain logging data for up to 200 days. To give a location per second but stay within ethical weight restrictions, the dead-reckoning method to reconstruct fine-scale movements between low resolution GPS fixes was adopted. To improve the accuracy of dead-reckoning estimates I improved the method using behavioural definition to identify real moves (steps, grazing, moving) and distinguish it from resting, grooming and other behaviours not leading to a displacement of the animal in space, allowing to selectively filter data to be dead-reckon. Using the data collected, I showed that central-place-based, but free-roaming, domestic goats exhibited efficient space-use by having time-dependent fanning out from their central place, which reduced local resource depletion. Models predicted that area-use increased logarithmically with herd size and duration. These finding could lead to improved livestock management in multi-functional alpine landscapes, to reduce the risk of over-grazing and manage interactions with other grazing species and clonflicts with other landuse needs. The goat grazing patterns were compared to those of wild ibex and revealed goats to be more adaptable, with the ibex being particularly vulnerable to changes in temperature, exacerbated by them preferring steep slopes with associated high metabolic costs and heat generation during ascent. These results could further inform management decisions regarding the survival of alpine ibex under projected climate change. Furthermore I developed new biologging approaches to investigate social interactions, specifically head-clashing in both species. This agonistic behaviour was associated with competition and the rut in ibex and was quantified using methods first developed for the domestic goat, where the behaviour appeared to relate primarily to competition for food. Using the goat as a surrogate species, the behaviour could be identified and mapped for the ibex, which highlighted areas and times important for head-clashing, including drastic increases during the rut. Finally, movement data and proxies for energy expenditure from three domestic species (sheep, cows and goats) and three wild species (ibex, mouflon and chamois) was utilised to produce species-specific energy landscapes across the terrains they used. This indicated that different anatomies and behaviours resulted in different, species-specific, movement costs for specific topographies and habitats. Energy use for travel across heterogeneous space depends, therefore, on the species concerned. These findings thus highlight the importance to consider that species with different life histories and ecological needs use landscapes in contrasting ways and my results can provide a more refined evidence base for the management and conservation of these species in alpine grasslands. These biologging approaches allow now also to address further management issues such as the responses to disturbances from tourists (hiking, skiers, etc.) and even reveal how species are more susceptible to climate change

Swimming with humans: biotelemetry reveals effects of “gold standard” regulated tourism on whale sharks

Wildlife tourism can benefit conservation of target species, however, it can have detrimental effects on animal behaviour and physiology. Whale shark Rhincodon typus tourism has seen recent rapid growth globally, but methods and regulations vary widely. Ningaloo Reef, Australia is considered “gold standard” whale shark tourism management due to legal regulation, strict enforcement, and high compliance. Rather than relying on observational data, we used biotelemetry to collect high-resolution data (20 Hz) on whale sharks’ movement behaviour in the presence or absence of tourists. Tourism encounters lasted an average of 62 min and swimming with tourists increased the activity levels of larger (> 7 m) but not smaller sharks. Given that activity levels positively correlate with energetic costs, it is likely the 18% increase seen in activity of large sharks would have incurred additional energetic costs. However, when considered as a proportion of daily energy requirements, these additional costs were only incurred for an average of 4% of a whale shark’s day. The tourism-induced impacts we found on the endangered whale sharks at this highly regulated tourism site would not have been apparent from purely observational studies, highlighting the utility of biotelemetry to quantify tourism-related impacts on wildlife

Why did the animal turn? Time‐varying step selection analysis for inference between observed turning‐points in high frequency data

Step selection analysis (SSA) is a fundamental technique for uncovering the drivers of animal movement decisions. Its typical use has been to view an animal as ‘selecting’ each measured location, given its current (and possibly previous) locations. Although an animal is unlikely to make decisions precisely at the times its locations are measured, if data are gathered at a relatively low frequency (every few minutes or hours) this is often the best that can be done. Nowadays, though, tracking data are increasingly gathered at very high frequencies, often ≥1 Hz, so it may be possible to exploit these data to perform more behaviourally-meaningful step selection analysis.Here, we present a technique to do this. We first use an existing algorithm to determine the turning-points in an animal's movement path. We define a ‘step’ to be a straight-line movement between successive turning-points. We then construct a generalised version of integrated SSA (iSSA), called time-varying iSSA (tiSSA), which deals with the fact that turning-points are usually irregularly spaced in time. We demonstrate the efficacy of tiSSA by application to data on both simulated animals and free-ranging goats Capra aegagrus hircus, comparing our results to those of regular iSSA with locations that are separated by a constant time-interval.Using (regular) iSSA with constant time-steps can give results that are misleading compared to using tiSSA with the actual turns made by the animals. Furthermore, tiSSA can be used to infer covariates that are dependent on the time between turns, which is not possible with regular iSSA. As an example, we show that our study animals tend to spend less time between successive turns when the ground is rockier and/or the temperature is hotter.By constructing a step selection technique that works between observed turning-points of animals, we enable step selection to be used on high-frequency movement data, which are becoming increasingly prevalent in modern biologging studies. Furthermore, since turning-points can be viewed as decisions, our method places step selection analysis on a more behaviourally-meaningful footing compared to previous techniques

Highlighting when animals expend excessive energy for travel using dynamic body acceleration

Travel represents a major cost for many animals so there should be selection pressure for it to be efficient – at minimum cost. However, animals sometimes exceed minimum travel costs for reasons that must be correspondingly important. We use Dynamic Body Acceleration (DBA), an acceleration-based metric, as a proxy for movement-based power, in tandem with vertical velocity (rate of change in depth) in a shark (Rhincodon typus) to derive the minimum estimated power required to swim at defined vertical velocities. We show how subtraction of measured DBA from the estimated minimum power for any given vertical velocity provides a “proxy for power above minimum” metric (PPAmin), highlighting when these animals travel above minimum power. We suggest that the adoption of this metric across species has value in identifying where and when animals are subject to compelling conditions that lead them to deviate from ostensibly judicious energy expenditure

How often should dead-reckoned animal movement paths be corrected for drift?

Abstract: Background: Understanding what animals do in time and space is important for a range of ecological questions, however accurate estimates of how animals use space is challenging. Within the use of animal-attached tags, radio telemetry (including the Global Positioning System, ‘GPS’) is typically used to verify an animal’s location periodically. Straight lines are typically drawn between these ‘Verified Positions’ (‘VPs’) so the interpolation of space-use is limited by the temporal and spatial resolution of the system’s measurement. As such, parameters such as route-taken and distance travelled can be poorly represented when using VP systems alone. Dead-reckoning has been suggested as a technique to improve the accuracy and resolution of reconstructed movement paths, whilst maximising battery life of VP systems. This typically involves deriving travel vectors from motion sensor systems and periodically correcting path dimensions for drift with simultaneously deployed VP systems. How often paths should be corrected for drift, however, has remained unclear. Methods and results: Here, we review the utility of dead-reckoning across four contrasting model species using different forms of locomotion (the African lion Panthera leo, the red-tailed tropicbird Phaethon rubricauda, the Magellanic penguin Spheniscus magellanicus, and the imperial cormorant Leucocarbo atriceps). Simulations were performed to examine the extent of dead-reckoning error, relative to VPs, as a function of Verified Position correction (VP correction) rate and the effect of this on estimates of distance moved. Dead-reckoning error was greatest for animals travelling within air and water. We demonstrate how sources of measurement error can arise within VP-corrected dead-reckoned tracks and propose advancements to this procedure to maximise dead-reckoning accuracy. Conclusions: We review the utility of VP-corrected dead-reckoning according to movement type and consider a range of ecological questions that would benefit from dead-reckoning, primarily concerning animal–barrier interactions and foraging strategies

Path tortuosity changes the transport cost paradigm in terrestrial animals

The time that animals spend travelling at various speeds and the tortuosity of their movement paths are two of the many things that affect space-use by animals. In this, high turn rates are predicted to be energetically costly, especially at high travel speeds, which implies that animals should modulate their speed according to path characteristics. When animals move so as to maximize distance and minimize metabolic energy expenditure, they travel most efficiently at the speed that gives them a minimum cost of transport (COTmin), a well-defined point for animals that move entirely in fluid media. Theoretical considerations show though, that land animals should travel at their maximum speed to minimize COT, which they do not, instead travelling at walking pace. So, to what extent does COTmin depend on speed and turn rate and how might this relate to movement paths? We measured oxygen consumption in humans walking along paths with varied tortuosity at defined speeds to demonstrate that the energetic costs of negotiating these paths increase disproportionately with both speed and angular velocity. This resulted in the COTmin occurring at very low speeds, and these COTmin speeds reduced with increased path tortuosity and angular velocity. Logged movement data from six free-ranging terrestrial species underpinned this because all individuals turned with greater angular velocity the slower their travel speeds across their full speed range. It seems, therefore, that land animals may strive to achieve minimum movement costs by reducing speed with increasing path variability, providing one of many possible explanations as to why speed is much lower than currently predicted based on lab measurements of mammalian locomotor performance

Dead-reckoning animal movements in R: a reappraisal using Gundog.Tracks

BackgroundFine-scale data on animal position are increasingly enabling us to understand the details of animal movement ecology and dead-reckoning, a technique integrating motion sensor-derived information on heading and speed, can be used to reconstruct fine-scale movement paths at sub-second resolution, irrespective of the environment. On its own however, the dead-reckoning process is prone to cumulative errors, so that position estimates quickly become uncoupled from true location. Periodic ground-truthing with aligned location data (e.g., from global positioning technology) can correct for this drift between Verified Positions (VPs). We present step-by-step instructions for implementing Verified Position Correction (VPC) dead-reckoning in R using the tilt-compensated compass method, accompanied by the mathematical protocols underlying the code and improvements and extensions of this technique to reduce the trade-off between VPC rate and dead-reckoning accuracy. These protocols are all built into a user-friendly, fully annotated VPC dead-reckoning R function; Gundog.Tracks, with multi-functionality to reconstruct animal movement paths across terrestrial, aquatic, and aerial systems, provided within the Additional file 4 as well as online (GitHub).ResultsThe Gundog.Tracks function is demonstrated on three contrasting model species (the African lion Panthera leo, the Magellanic penguin Spheniscus magellanicus, and the Imperial cormorant Leucocarbo atriceps) moving on land, in water and in air. We show the effect of uncorrected errors in speed estimations, heading inaccuracies and infrequent VPC rate and demonstrate how these issues can be addressed.ConclusionsThe function provided will allow anyone familiar with R to dead-reckon animal tracks readily and accurately, as the key complex issues are dealt with by Gundog.Tracks. This will help the community to consider and implement a valuable, but often overlooked method of reconstructing high-resolution animal movement paths across diverse species and systems without requiring a bespoke application

A História da Alimentação: balizas historiográficas

Os M. pretenderam traçar um quadro da História da Alimentação, não como um novo ramo epistemológico da disciplina, mas como um campo em desenvolvimento de práticas e atividades especializadas, incluindo pesquisa, formação, publicações, associações, encontros acadêmicos, etc. Um breve relato das condições em que tal campo se assentou faz-se preceder de um panorama dos estudos de alimentação e temas correia tos, em geral, segundo cinco abardagens Ia biológica, a econômica, a social, a cultural e a filosófica!, assim como da identificação das contribuições mais relevantes da Antropologia, Arqueologia, Sociologia e Geografia. A fim de comentar a multiforme e volumosa bibliografia histórica, foi ela organizada segundo critérios morfológicos. A seguir, alguns tópicos importantes mereceram tratamento à parte: a fome, o alimento e o domínio religioso, as descobertas européias e a difusão mundial de alimentos, gosto e gastronomia. O artigo se encerra com um rápido balanço crítico da historiografia brasileira sobre o tema

Synthese und Transformationen cyclischer Nitrone: Ein Weg zur Herstellung hoch-wirksamer Inhibitoren von α-L-Fucosidase

The main themes of this PhD thesis entailed the synthesis of new candidates for glycosidase inhibition assays. Glycosidases catalyze the degradation (i.e. hydrolytic cleavage or transfer) of glycosidic bonds. The synthesis of suitable, selective inhibitors of glycosidases may be a tool to stop detrimental or disease-related cell processes and may be of therapeutic value. In particular, this work focused on the synthesis of alpha-L-fucosidase inhibitors. We choose to synthesise a library of polyhydroxylated pyrrolidines, bearing extended aglycon side-chains and to investigate the biological properties, i.e the inhibiton against fucosidases, in a systematic manner. The route to these pyrrolidines relied on the halogen-induced cyclisation of unsaturated hydroxylamines, which in turn can be derived from simple carbohydrates, such as D-ribose. The cyclisation leads to the formation of cyclic nitrones which are a class of synthetically versatile compounds. The key nitrone compound with L-lyxo configuration can be transformed in a few steps into actual fucosidase inhibitors, through a Grignard addition (to install the side-chain) followed by a simple reduction/deprotection protocol. This rapidly provided us with a library of polyhydroxylated pyrrolidines bearing several para-substituted aromatic side-chains. Several pyrrolidines as fucosidase inhibitor candidates were active in the low-micromolar range. The best candidates showed inhibition against fucosidase even at concentrations as low as 1.2 nM, resulting in some of the most potent inhibitors in this class currently known in the literature. Further elements of the dissertation involved the synthesis of six-membered nitrones with L-fuco configuration and their elaboration into fucosidase inhibitors (one example), according to a new route developed in this Thesis. This thesis also focused on an investigation of the oxidation selectivity of tri- and tetra-substituted N-hydroxypyrrolidines and, to a lesser extent, the subsequent reactions of the new nitrones that were created. Two oxidation reagents were compared, revealing striking kinetic - though hardly any regioisomeric - differences in the reaction outcomes. Special electronic effects of neighbouring substituents were found, in specific cases, to effect a drastic change in oxidation regioselectivity to provide some surprising results.Das Ziel der vorliegenden Arbeit bestand darin, die Entwicklung neuer Glycosidase Inhibitioren zu synthesieren. Glycosidasen katalysieren den Abbau von glycosidischen Bindungen und spielen eine wichtige Rolle bei der Herstellung von N-Glykoproteinen. Solche Proteine sind an einer Vielzahl biologisch relevanter Prozesse und krankhafter Veränderungen beteiligt. Aufgrund dieser Eigenschaften sind diese Verbindungen möglicherweise zur Behandlung von Krankheiten geeignet. In dieser Arbeit wurden gezielt neue Kandidaten für die Hemmung von alpha-L-Fucosidasen ins Visier genommen. Aus einer hervorgegangen Arbeit entpuppte sich bestimmte Pyrrolidine mit L-fuco-ähnlicher Konfiguration als starke Inhibitoren von alpha-L-Fucosidasen, die einen lipophilen Rest mit p-System aufweisen. In dieser Arbeit wurde den Effekt der C-2-Seitenkette systematisch untersucht. Der Weg zu diesen diastereo- und enantiomerenreinen, hochfunktionalisierten Pyrrolidinen war möglich durch brom-induzierte Cyclisierung eines Pentenoseoxims, ausgehend von D-Ribose. Die elektrophile Cyclisierung von Oximen stellte den Schlüsselschritt dar und führte zu den cyclischen Nitronen, bei denen das Pyrrol-1-oxid als Synthesebaustein mit L-lyxo-Konfiguration bevorzugt gebildet wurde. Die Addition von Grignard-Reagenzien an dieses Nitron verlief hoch-diastereoselektiv und lieferte die tetrasubstituierten N-Hydroxypyrrolidine. Durch einfache zweistufige Reduktion und Schutzgruppen-Abspaltung konnten die neuen Pyrrolidin-Polyole erhalten werden, deren biologische Aktivität in Enzymtests evaluiert werden sollte. Auf Grund dieser Ergebnisse sollten Struktur-Wirkungsbeziehungen insbesondere im Hinblick auf Fucosidase-Inhibition formuliert werden. Alle untersuchten Pyrrolidin-Polyole mit para-Substituenten am Phenyl-Ring besaßen starke Aktivität gegenüber alpha-L-Fucosidasen. Für die Stärke der Inhibition ist der Charakter des para-Substituenten von großer Bedeutung. Die stärkste Inhibition im Nanomolar-Bereich wurde mit dem Biphenyl-substituierten Pyrrolidin (Ki = 1.2 nM) erzielt. Ein weiterer Teil dieser Arbeit befasst sich mit der stereoselektiven Synthese von substituierten Piperidinen. In folgenden wurde das benötigte L-fuco-konfigurierte Nitron über eine Bromcyclisierung des Triisopropylsilyl-geschützten Hexenoseoxims dargestellt. Das ungesättigte Oxim war aus D-Lyxose in 8 Schritten gut zugänglich. Die biologische Aktivität dieses Piperdines wurde ebenefalls untersucht. Die Oxidation von tri- bzw. tetra-substituierten N-Hydroxypyrrolidinen wurde mit Mangan(IV)-oxid und Quecksilber(I)-oxid als Oxidations-Reagenzien untersucht. Daraus ist eine neue Klasse von Brommethyl-ketonitronen entstanden, die sich vermutlich als Synthesebausteine verwenden lassen

Combined effects of landscape fragmentation and sampling frequency of movement data on the assessment of landscape connectivity

Abstract Background - Network theory is largely applied in real-world systems to assess landscape connectivity using empirical or theoretical networks. Empirical networks are usually built from discontinuous individual movement trajectories without knowing the effect of relocation frequency on the assessment of landscape connectivity while theoretical networks generally rely on simple movement rules. We investigated the combined effects of relocation sampling frequency and landscape fragmentation on the assessment of landscape connectivity using simulated trajectories and empirical high-resolution (1 Hz) trajectories of Alpine ibex ( Capra ibex ). We also quantified the capacity of commonly used theoretical networks to accurately predict landcape connectivity from multiple movement processes. Methods – We simulated forager trajectories from continuous correlated biased random walks in simulated landscapes with three levels of landscape fragmentation. High-resolution ibex trajectories were reconstructed using GPS-enabled multi-sensor biologging data and the dead-reckoning technique. For both simulated and empirical trajectories, we generated spatial networks from regularly resampled trajectories and assessed changes in their topology and information loss depending on the resampling frequency and landscape fragmentation. We finally built commonly used theoretical networks in the same landscapes and compared their predictions to actual connectivity. Results - We demonstrated that an accurate assessment of landscape connectivity can be severely hampered (e.g., up to 66% of undetected visited patches and 29% of spurious links) when the relocation frequency is too coarse compared to the temporal dynamics of animal movement. However, the level of landscape fragmentation and underlying movement processes can both mitigate the effect of relocation sampling frequency. We also showed that network topologies emerging from different movement behaviours and a wide range of landscape fragmentation were complex, and that commonly used theoretical networks accurately predicted only 30–50% of landscape connectivity in such environments. Conclusions - Very high-resolution trajectories were generally necessary to accurately identify complex network topologies and avoid the generation of spurious information on landscape connectivity. New technologies providing such high-resolution datasets over long period should thus grow in the movement ecology sphere. In addition, commonly used theoretical models should be applied with caution to the study of landscape connectivity in real-world systems as they did not perform well as predictive tools