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

GUNNER, RICHARD M.; HOLTON, MARK D.; SCANTLEBURY, DAVID M.; HOPKINS, PHIL; SHEPARD, EMILY L. C.; FELL, ADAM J.; GARDE, BAPTISTE; QUINTANA, FLAVIO; GÓMEZ-LAICH, AGUSTINA; YODA, KEN; YAMAMOTO, TAKASHI; ENGLISH, HOLLY; FERREIRA, SAM; GOVENDER, DANNY; VILJOEN, PAULI; BRUNS, ANGELA; VAN SCHALKWYK, O. LOUIS; COLE, NIK C.; TATAYAH, VIKASH; BÖRGER, LUCA; REDCLIFFE, JAMES; BELL, STEPHEN H.; MARKS, NIKKI J.; BENNETT, NIGEL C.; TONINI, MARIANO H.; WILLIAMS, HANNAH J.; DUARTE, CARLOS M.; VAN ROOYEN, MARTIN C.; BERTELSEN, MADS F.; TAMBLING, CRAIG J.; WILSON, RORY P.

Animal Biotelemetry

BioMed Central

Año: 2021 vol. 9 p. 9 - 43

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 ?Verifed 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 dif‑ferent forms of locomotion (the African lion Panthera leo, the red-tailed tropicbird Phaethon rubricauda, the Magellanic penguin Spheniscus magellanicus, and the imperial cormorantLeucocarbo atriceps). Simulations were performed to examine the extent of dead-reckoning error, relative to VPs, as a function of Verifed Position correction (VP correction) rate and the efect 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-reck‑oned 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 beneft from dead-reckoning, primarily concerning animal?barrier interac‑tions and foraging strategies.