How to Radio-Tag Endangered Animals

Choose the right type of tag and attachment. This means understanding the connection between animal species and tag types. RFID tags come in a range of sizes and can be attached to animals in a number of ways. Fitted collars with tags are generally used for mammals. Tags also can be glued onto birds' tail feathers or mammals' bare skin. They can also be surgically implanted; this option is advantageous for animals without defined necks, such as snakes, as well as for burrowing animals and those with sensitive skins, such as amphibians. Still more options are tags attached to backpack harnesses (these are used on fish and amphibians as well as for attaching tags heavier than 4 grams to birds) or tags clipped onto animals' ears. The tag choice will depend on the kind of animal you're tagging, its size and its lifestyle.

Test your tag system on captive animals of your target species before attempting to use it on wild-caught animals. This will give you a better idea of how your chosen system works with animals of different sizes and temperaments.

Capture the animal or animals you want to tag. Treat all captured animals with care and respect when handling them. Avoid capturing and tagging animals during their reproductive season; some species are especially sensitive to stress during this time. If possible, capture and tag more than one animal per social group, in case one of the tags fails or comes off.

Examine the animal or animals to be tagged. Check for age, sex, size and general health to ensure your tag choice is appropriate. Avoid tagging sick or injured animals unless there is a pressing scientific need to do so; the process could increase their stress levels and further endanger their health. If you capture a previously tagged animal that appears to have suffered ill effects from the tag, do not tag it again.

Put the tag on the animal. Test the tag you plan to use both before and after putting it on the animal. Ensure that the tag attachment is secure and comfortable (e.g., make sure nothing sharp or irritating is in contact with the animal's skin). Observe the animal's behavior before releasing it to ensure the transmitter does not impede the animal's movement or balance.