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

Area of Science:

• Ecology
• Animal Movement Ecology
• Biologging Technology

Background:

• Accurate animal space-use estimation is crucial for ecological research but challenging.
• Traditional radio telemetry (including GPS) uses Verified Positions (VPs), limiting path and distance accuracy due to temporal/spatial resolution.
• Dead-reckoning offers improved path accuracy and resolution while conserving battery life, but optimal correction frequency remains unclear.

Purpose of the Study:

• To review the utility of dead-reckoning for reconstructing animal movement paths.
• To evaluate dead-reckoning error relative to Verified Positions (VPs) based on correction rates.
• To assess the impact of dead-reckoning on distance traveled estimates and propose advancements.

Main Methods:

• Reviewed dead-reckoning utility across four diverse species: African lion, red-tailed tropicbird, Magellanic penguin, and imperial cormorant.
• Conducted simulations to quantify dead-reckoning error as a function of Verified Position (VP) correction rate.
• Analyzed sources of measurement error in VP-corrected dead-reckoned tracks.

Main Results:

• Dead-reckoning error was greatest for animals moving in air and water.
• Simulations revealed the extent of dead-reckoning error relative to VPs based on VP correction rate.
• Identified sources of measurement error in VP-corrected tracks and proposed methods to enhance accuracy.

Conclusions:

• VP-corrected dead-reckoning is valuable for various movement types and ecological questions.
• Dead-reckoning is particularly beneficial for studying animal-barrier interactions and foraging strategies.
• Advancements in dead-reckoning procedures can maximize tracking accuracy for ecological research.