As a general rule of thumb, collars weigh < 5% of animal body weight. Collars and tags are used on select taxa to study their use of heterogeneous habitats, to understand territorial behavior, migration or dispersal, to visualize overlap between species in space and time, to monitor animal survival and well-being, and to conduct follow-up research.
Collars/tags are placed with the following guidelines in mind:
In this program all animals are habituated to traps for annual health monitoring, so it is possible to replace/remove tracking devices. We rely on longitudinal data to demonstrate that the collars used do not effect the survival or reproduction of the study subjects.
In cases in which recapture is not anticipated, collars are voluntarily damaged in a way that will cause them to fall off over time due to normal wear and tear. Alternatively, collars are attached with a temmporary aterial that will fall off over time (e.g. thin chain, skin glue and thin-stretch plastics).
If recapture is not anticipated and when weight is not a factor, pre-programmed drop-off mechanisms are considered. However, this feature is not a certainty, and thus the above considerations always apply.
Poor sizing of animal collars will result in collars falling off prematurely, or constraining an animal's normal growth and causing excessive abrasion, injury, or worst case, death. Permanent, non-expanding radio collars are NEVER to be placed on juveniles or sub-adults with as yet unknown growth potential.
According to the collar type, monitor the animal for normal movement in the days following capture, and then develop a schedule for checking on the animal regularly until the 1 year mark. After 1 year, attempt to recapture the animal to check health status, and sizing and integrity of the tracking device.