Ear tag
- Pronunciation
- /EER tag/
- Category
- Collection Methods
- Singular
- ear tag
- Plural
- ear tags
Definition
A small, externally attached identification marker fixed to the body of an animal, typically through the or a thin appendage segment, to enable individual recognition in longitudinal studies. In research, modified ear tags or analogous devices are applied to larger insects, spiders, or other chelicerates for mark-recapture estimates, movement tracking, and behavioral observation. Tags may be passive (numbered, colored, or reflective) or active (electronic RFID transponders), with placement depending on -specific anatomy—often on the , leg segments, or in arachnids, and on the pronotum, , or wing in insects. Attachment must minimize interference with molting, locomotion, sensory structures, and social interactions.
Etymology
From livestock husbandry, where tags are fixed through the ear pinna; adapted to by analogy of placement on thin, expendable, or regenerable body regions.
Example
Researchers studying wolf spider (Lycosidae) in grassland use tiny colored plastic ear tags affixed to the with cyanoacrylate adhesive, allowing individual identification during repeated observations without impairing locomotion or prey capture.
Synonyms
- ear marker
- external tag
Related Terms
- mark-recapture
- passive integrated transponder
- elytral marking
- mutilation marking
- individual identification
- longitudinal study
- Population ecology
Usage Notes
In work, 'ear tag' is often used loosely for any small external tag regardless of attachment site; may prefer 'body tag' or -specific terms (e.g., 'elytral tag' for ). Metal tags are generally avoided in small arthropods due to mass and corrosion; plastic or paper tags with adhesive are standard. RFID microtags require readers and are cost-prohibitive for large-n studies but enable automated detection. Attachment site must avoid joints, sensory hairs, and ecdysial . The term carries no implication of actual 'ears' in arthropods.