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 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 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 Movement ecology of vulnerable lowland tapirs across a gradient of human disturbance

2021 ◽  
Author(s):  
E P Medici ◽  
Stefano Mezzini ◽  
Christen Herbert Fleming ◽  
Justin Calabrese ◽  
Michael J Noonan
Keyword(s):  
Home Range ◽  
Atlantic Forest ◽  
Human Disturbance ◽  
Animal Movement ◽  
Human Impacts ◽  
Movement Ecology ◽  
Space Use ◽  
Conservation Strategies ◽  
Detectable Effect ◽  
Movement Behaviour

Animal movement is a key ecological process that is tightly coupled to local environmental conditions. While agriculture, urbanisation, and transportation infrastructure are critical to human socio-economic improvement, these have spurred substantial changes in animal movement across the globe with potential impacts on fitness and survival. Notably, however, human disturbance can have differential effects across species, and responses to human activities are thus largely taxa and context specific. As human disturbance is only expected to worsen over the next decade it is critical to better understand how species respond to human disturbance in order to develop effective, case-specific conservation strategies. Here, we use an extensive telemetry dataset collected over 22 years to fill a critical knowledge gap in the movement ecology of lowland tapirs (Tapirus terrestris) across a gradient of human disturbance within three biomes in southern Brazil: the Pantanal, Cerrado, and Atlantic Forest. From these data we found that the mean home range size across all monitored tapirs was 8.31 km2 (95% CI: 6.53 - 10.42), with no evidence that home range sizes differed between sexes nor age groups. Interestingly, although the Atlantic Forest, Cerrado, and Pantanal vary substantially in habitat composition, levels of human disturbance, and tapir population densities, we found that lowland tapir movement behaviour and space use were consistent across all three biomes. Human disturbance also had no detectable effect on lowland tapir movement. Lowland tapirs living in the most altered habitats we monitored exhibited movement behaviour that was comparable to that of tapirs living in a near pristine environment. Contrary to our expectations, we observed very little individual variability in lowland tapir space use and movement, and human impacts on the landscape also had no measurable effect on their movement. Lowland tapir movement behaviour thus appears to exhibit very little phenotypic plasticity. Crucially, the lack of any detectable response to anthropogenic disturbance suggests that human modified habitats risk being ecological traps for tapirs and this information should be factored into conservation actions and species management aimed towards protecting lowland tapir populations.

scholarly journals Decision rules for determining terrestrial movement and the consequences for filtering high-resolution GPS tracks – A case study using the African Lion (Panthera leo)

2021 ◽  
Author(s):  
Richard Michael Gunner ◽  
Rory P Wilson ◽  
Mark D Holton ◽  
Phil Hopkins ◽  
Stephen H Bell ◽  
...  
Keyword(s):  
High Resolution ◽  
Decision Rules ◽  
Movement Ecology ◽  
Animal Behaviour ◽  
Panthera Leo ◽  
Motion Sensors ◽  
Fine Scale ◽  
Quick Method ◽  
Gps Tracks ◽  
Terrestrial Movement

Abstract The combined use of Global Positioning System (GPS) technology and motion sensors within the discipline of movement ecology has increased over recent years. This is particularly the case for instrumented wildlife, with many studies now opting to record parameters at high (infra-second) sampling frequency. However, the detail with which GPS loggers can elucidate fine-scale movement depends on the precision and accuracy of fixes, with accuracy (specifically, location error and fix success rate) being affected by signal reception. We hypothesised that animal behaviour was the main factor affecting fix inaccuracy (particularly for collar-mounted tags sampling at high frequency). In conjunction to this, inherent GPS positional noise (‘jitter’), would be most apparent during GPS fixes for non-moving locations, thereby producing disproportionate error during rest periods. A Movement Verified Filtering (MVF) protocol was constructed to compare GPS-derived speed data to dynamic body acceleration (DBA). This was collected by a simultaneously deployed tri-axial accelerometer, to provide a computationally quick method for identifying genuine travelling movement. This method was tested on 11 free-ranging lions ( Panthera leo ) within the Kgalagadi Transfrontier park in the Kalahari Desert, fitted with collar-mounted GPS units and tri-axial motion sensors (Daily Diary; DD) recording at 1 and 40 Hz, respectively. The findings support the hypothesis and show that distance moved estimates were, on average, overestimated by > 80 % prior to GPS screening. We present the conceptual and mathematical protocols for screening fix inaccuracy within high resolution GPS datasets. We demonstrate the importance that MVF has for avoiding inaccurate and biased estimates of movement and caution the accuracy of findings from previous studies that employed minimal GPS pre-processing . Throughout, we address the applicability of comparing fine-scale indices of GPS- and motion sensor-borne data in tandem to qualify animal behaviour.

scholarly journals Variable Intraspecific Space Use Supports Optimality in an Apex Predator

2021 ◽  
Author(s):  
S. P. Finnegan ◽  
N. J. Svoboda ◽  
N. L. Fowler ◽  
S. L. Schooler ◽  
J. L. Belant
Keyword(s):  
Optimality Theory ◽  
Ursus Arctos ◽  
Animal Movement ◽  
Movement Ecology ◽  
Optimal Strategies ◽  
Space Use ◽  
Home Ranges ◽  
Island Populations ◽  
Resource Dispersion ◽  
Resource Dispersion Hypothesis

Abstract Within optimality theory, an animal’s home range can be considered a fitness-driven attempt to obtain resources for survival and reproduction while minimizing costs. We assessed whether brown bears (Ursus arctos) in two island populations maximized resource patches within home ranges (Resource Dispersion Hypothesis [RDH]) or occupied only areas necessary to meet their biological requirements (Temporal Resource Variability Hypothesis [TRVH]) at annual and seasonal scales. We further examined how intrinsic factors (age, reproductive status) affected optimal choices. We found dynamic patterns of space use between populations, with support for RDH and TRVH at both scales. The RDH was likely supported seasonally as a result of bears maximizing space use to obtain a mix of nutritional resources for weight gain. While annually, support for RDH likely reflected changing abundances and distributions of foods within different timber stand classes. TRVH was supported at both scales, with bears minimizing space use when food resources were temporally concentrated. Range sizes and optimal strategies varied among sex and reproductive classes, with males occupying larger ranges, supporting mate seeking behavior and increased metabolic demands of larger body sizes. This work emphasizes the importance of scale when examining animal movement ecology, as optimal behavioral decisions are scale dependent.

Resource selection and space use ofMyotis evotisin a western juniper woodland in Oregon

2018 ◽  
Vol 100 (1) ◽  
pp. 239-248
Author(s):  
Christopher R Anthony ◽  
Dana M Sanchez
Keyword(s):  
Resource Selection ◽  
Space Use ◽  
Western Juniper ◽  
Juniper Woodland

scholarly journals The home-range concept: are traditional estimators still relevant with modern telemetry technology?

2010 ◽  
Vol 365 (1550) ◽  
pp. 2221-2231 ◽  
Author(s):  
John G. Kie ◽  
Jason Matthiopoulos ◽  
John Fieberg ◽  
Roger A. Powell ◽  
Francesca Cagnacci ◽  
...  
Keyword(s):  
Home Range ◽  
New Technologies ◽  
Animal Movement ◽  
Space Use ◽  
Ease Of Use ◽  
Home Ranges ◽  
Data Intensive ◽  
Use Patterns ◽  
Location Data ◽  
Utilization Distributions

Recent advances in animal tracking and telemetry technology have allowed the collection of location data at an ever-increasing rate and accuracy, and these advances have been accompanied by the development of new methods of data analysis for portraying space use, home ranges and utilization distributions. New statistical approaches include data-intensive techniques such as kriging and nonlinear generalized regression models for habitat use. In addition, mechanistic home-range models, derived from models of animal movement behaviour, promise to offer new insights into how home ranges emerge as the result of specific patterns of movements by individuals in response to their environment. Traditional methods such as kernel density estimators are likely to remain popular because of their ease of use. Large datasets make it possible to apply these methods over relatively short periods of time such as weeks or months, and these estimates may be analysed using mixed effects models, offering another approach to studying temporal variation in space-use patterns. Although new technologies open new avenues in ecological research, our knowledge of why animals use space in the ways we observe will only advance by researchers using these new technologies and asking new and innovative questions about the empirical patterns they observe.

scholarly journals Site fidelity and localised homing behaviour in three-spined sticklebacks (Gasterosteus aculeatus)

Behaviour ◽  
2013 ◽  
Vol 150 (14) ◽  
pp. 1689-1708 ◽  
Author(s):  
A.J.W. Ward ◽  
R. James ◽  
A.D.M. Wilson ◽  
M.M. Webster
Keyword(s):  
Social Facilitation ◽  
Site Fidelity ◽  
Gasterosteus Aculeatus ◽  
Home Ranges ◽  
Small Fish ◽  
Behavioural Ecology ◽  
Model Species ◽  
Homing Behaviour ◽  
Capture Site

The ability of animals to disperse towards their original home range following displacement has been demonstrated in a number of species. However, little is known about the homing ability of three-spine sticklebacks (Gasterosteus aculeatus), an important model species in behavioural ecology. In addition, few studies have examined the role of social facilitation in relation to homing behaviour in fishes. We examined homing behaviour of sticklebacks displaced over distances of between 80 m and 160 m in land-drains with directional water flow. Fish were translocated from their original capture site, tagged and then released either in groups or solitarily. We performed recapture transects either one or two days later. Data provided by recaptured sticklebacks show that the fish dispersed in the direction of their original capture site. Although fish translocated downstream typically moved further than those translocated upstream, both dispersed towards their original capture site. There was no difference between fish released solitarily or in groups in their homing ability and indeed there was little evidence that fish translocated in groups remained together following their release. The homing ability of the fish was demonstrated by the finding that up to 80% of fish returned to their home ranges within two days of release over a distance equivalent to approximately 5000 body lengths of these small fish.

Sign in / Sign up

Export Citation Format

Share Document