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

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Richard M. Gunner ◽  
Mark D. Holton ◽  
Mike D. Scantlebury ◽  
O. Louis van Schalkwyk ◽  
Holly M. English ◽  
...  
Keyword(s):  
Animal Movement ◽  
Movement Ecology ◽  
Dead Reckoning ◽  
Fine Scale ◽  
Magellanic Penguin ◽  
True Location ◽  
Position Correction ◽  
Ground Truthing ◽  
User Friendly ◽  
Aerial Systems

Abstract Background Fine-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). Results The 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. Conclusions The 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.

scholarly journals Dead-Reckoning Animal Movements in R – A Reappraisal Using Gundog.Tracks

2021 ◽  
Author(s):  
Richard Michael Gunner ◽  
Mark D Holton ◽  
Mike D Scantlebury ◽  
Louis van Schalkwyk ◽  
Holly M English ◽  
...  
Keyword(s):  
Animal Movement ◽  
Movement Ecology ◽  
Dead Reckoning ◽  
Supplementary Information ◽  
Fine Scale ◽  
Magellanic Penguin ◽  
True Location ◽  
Position Correction ◽  
Ground Truthing ◽  
Aerial Systems

Abstract Background Fine-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). Yet relatively few bio-logging studies have adopted this approach due to an apparent inaccessibility of the complex analytical processes involved. 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 supplementary information as well as online (GitHub). Results The 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, respectively. We show the effect of uncorrected errors in speed estimations, heading inaccuracies and infrequent VPC rate and demonstrate how these issues can be addressed. Conclusions The 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.

scholarly journals Circles within spirals, wheels within wheels; Body rotation facilitates critical insights into animal behavioural ecology

2021 ◽  
Author(s):  
◽  
Richard M. Gunner
Keyword(s):  
Resource Selection ◽  
Animal Movement ◽  
Movement Ecology ◽  
Dead Reckoning ◽  
Space Use ◽  
Behavioural Ecology ◽  
Motion Sensors ◽  
Fine Scale ◽  
Body Rotation ◽  
Model Species

How animals behave is fundamental to enhancing their lifetime fitness, so defining how animals move in space and time relates to many ecological questions, including resource selection, activity budgets and animal movement networks. Historically, animal behaviour and movement has been defined by direct observation, however recent advancements in biotelemetry have revolutionised how we now assess behaviour, particularly allowing animals to be monitored when they cannot be seen. Studies now pair ‘convectional’ radio telemetries with motion sensors to facilitate more detailed investigations of animal space-use. Motion sensitive tags (containing e.g., accelerometers and magnetometers) provide precise data on body movements which characterise behaviour, and this has been exemplified in extensive studies using accelerometery data, which has been linked to space-use defined by GPS. Conversely, consideration of body rotation (particularly change in yaw) is virtually absent within the biologging literature, even though various scales of yaw rotation can reveal important patterns in behaviour and movement, with animal heading being a fundamental component characterising space-use. This thesis explores animal body angles, particularly about the yaw axis, for elucidating animal movement ecology. I used five model species (a reptile, a mammal and three birds) to demonstrate the value of assessing body rotation for investigating fine-scale movement-specific behaviours. As part of this, I advanced the ‘dead-reckoning’ method, where fine-scale animal movement between temporally poorly resolved GPS fixes can be deduced using heading vectors and speed. I addressed many issues with this protocol, highlighting errors and potential solutions but was able to show how this approach leads to insights into many difficult-to-study animal behaviours. These ranged from elucidating how and where lions cross supposedly impermeable man-made barriers to examining how penguins react to tidal currents and then navigate their way to their nests far from the sea in colonies enclosed within thick vegetation.

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

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Richard M. Gunner ◽  
Mark D. Holton ◽  
David M. Scantlebury ◽  
Phil Hopkins ◽  
Emily L. C. Shepard ◽  
...  
Keyword(s):  
Animal Movement ◽  
Radio Telemetry ◽  
Dead Reckoning ◽  
Foraging Strategies ◽  
Battery Life ◽  
Magellanic Penguin ◽  
Position Correction ◽  
Movement Type ◽  
Phaethon Rubricauda ◽  
Straight Lines

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.

scholarly journals How Often Should Dead-Reckoned Animal Movement Paths be Corrected for Drift?

2021 ◽  
Author(s):  
Richard Michael gunner ◽  
Mark D Holton ◽  
Mike D Scantlebury ◽  
Phil Hopkins ◽  
Emily LC Shepard ◽  
...  
Keyword(s):  
Animal Movement ◽  
Radio Telemetry ◽  
Dead Reckoning ◽  
Foraging Strategies ◽  
Battery Life ◽  
Magellanic Penguin ◽  
Position Correction ◽  
Movement Type ◽  
Phaethon Rubricauda ◽  
Straight Lines

Abstract BackgroundUnderstanding 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 & ResultsHere, 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.ConclusionsWe 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.

Fine-scale body and head movements allow to determine prey capture events in the Magellanic Penguin (Spheniscus magellanicus)

2021 ◽  
Vol 168 (6) ◽  
Author(s):  
Monserrat Del Caño ◽  
Flavio Quintana ◽  
Ken Yoda ◽  
Giacomo Dell’Omo ◽  
Gabriela S. Blanco ◽  
...  
Keyword(s):  
Prey Capture ◽  
Head Movements ◽  
Fine Scale ◽  
Magellanic Penguin ◽  
Spheniscus Magellanicus

scholarly journals Step by step: reconstruction of terrestrial animal movement paths by dead-reckoning

2015 ◽  
Vol 3 (1) ◽  
Author(s):  
O. R. Bidder ◽  
J. S. Walker ◽  
M. W. Jones ◽  
M. D. Holton ◽  
P. Urge ◽  
...  
Keyword(s):  
Animal Movement ◽  
Dead Reckoning ◽  
Terrestrial Animal

scholarly journals Coupling movement and landscape ecology for animal conservation in production landscapes

2018 ◽  
Vol 285 (1870) ◽  
pp. 20172272 ◽  
Author(s):  
Tim S. Doherty ◽  
Don A. Driscoll
Keyword(s):  
Landscape Ecology ◽  
Structural Changes ◽  
Conservation Management ◽  
Animal Movement ◽  
Structural Connectivity ◽  
Movement Ecology ◽  
Animal Conservation ◽  
Conventional Management ◽  
Habitat Conversion ◽  
Management Approaches

Habitat conversion in production landscapes is among the greatest threats to biodiversity, not least because it can disrupt animal movement. Using the movement ecology framework, we review animal movement in production landscapes, including areas managed for agriculture and forestry. We consider internal and external drivers of altered animal movement and how this affects navigation and motion capacities and population dynamics. Conventional management approaches in fragmented landscapes focus on promoting connectivity using structural changes in the landscape. However, a movement ecology perspective emphasizes that manipulating the internal motivations or navigation capacity of animals represents untapped opportunities to improve movement and the effectiveness of structural connectivity investments. Integrating movement and landscape ecology opens new opportunities for conservation management in production landscapes.

scholarly journals Emerging Perspectives on Resource Tracking and Animal Movement Ecology

2020 ◽  
Author(s):  
Briana Abrahms ◽  
Ellen O. Aikens ◽  
Jonathan B. Armstrong ◽  
William W. Deacy ◽  
Matthew J. Kauffman ◽  
...  
Keyword(s):  
Animal Movement ◽  
Movement Ecology ◽  
Resource Tracking

scholarly journals Behavioural valuation of landscapes using movement data

2019 ◽  
Vol 374 (1781) ◽  
pp. 20180046 ◽  
Author(s):  
George Wittemyer ◽  
Joseph M. Northrup ◽  
Guillaume Bastille-Rousseau
Keyword(s):  
Animal Movement ◽  
Temporal Dynamics ◽  
Economic Valuation ◽  
Movement Ecology ◽  
Optimization Theory ◽  
Population Level ◽  
Animal Behaviour ◽  
Tracking Data ◽  
Movement Data ◽  
Spatio Temporal

Wildlife tracking is one of the most frequently employed approaches to monitor and study wildlife populations. To date, the application of tracking data to applied objectives has focused largely on the intensity of use by an animal in a location or the type of habitat. While this has provided valuable insights and advanced spatial wildlife management, such interpretation of tracking data does not capture the complexity of spatio-temporal processes inherent to animal behaviour and represented in the movement path. Here, we discuss current and emerging approaches to estimate the behavioural value of spatial locations using movement data, focusing on the nexus of conservation behaviour and movement ecology that can amplify the application of animal tracking research to contemporary conservation challenges. We highlight the importance of applying behavioural ecological approaches to the analysis of tracking data and discuss the utility of comparative approaches, optimization theory and economic valuation to gain understanding of movement strategies and gauge population-level processes. First, we discuss innovations in the most fundamental movement-based valuation of landscapes, the intensity of use of a location, namely dissecting temporal dynamics in and means by which to weight the intensity of use. We then expand our discussion to three less common currencies for behavioural valuation of landscapes, namely the assessment of the functional (i.e. what an individual is doing at a location), structural (i.e. how a location relates to use of the broader landscape) and fitness (i.e. the return from using a location) value of a location. Strengthening the behavioural theoretical underpinnings of movement ecology research promises to provide a deeper, mechanistic understanding of animal movement that can lead to unprecedented insights into the interaction between landscapes and animal behaviour and advance the application of movement research to conservation challenges. This article is part of the theme issue ‘Linking behaviour to dynamics of populations and communities: application of novel approaches in behavioural ecology to conservation’.

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