Animal lifestyle affects acceptable mass limits for attached tags

Area of Science:

• Ecology
• Animal Biologging
• Biomechanics

Background:

• Animal-attached devices are vital for ecological research.
• Current guidelines recommend tag mass not exceed 3% of an animal's body mass to minimize harm.
• These guidelines overlook forces generated by animal movement.

Purpose of the Study:

• To develop a new method for determining acceptable animal tag mass limits.
• To account for forces exerted by animal movement, not just static tag mass.
• To revise ethical guidelines for attaching devices to wildlife.

Main Methods:

• Utilized collar-attached accelerometer data from 10 diverse terrestrial species.
• Quantified animal "athleticism" based on time spent accelerating.
• Calculated forces exerted by tags (acceleration × tag mass) to derive new limits.

Main Results:

• A revised method suggests optimal tag masses should be 1.6%–2.98% of body mass, varying with athleticism.
• Existing "3%" tags can exert forces equivalent to 4%–19% of body mass in carnivores during movement.
• A cheetah experienced tag forces up to 54% of its body mass while hunting.

Conclusions:

• The 3% rule is insufficient as it ignores dynamic forces from animal movement.
• New methods are needed to accurately assess the impact of attached devices on animal welfare.
• Ethical guidelines for animal tagging must be updated to incorporate movement-induced forces.