As someone who puts radio collars on game animals, I can assure you that the biologists will be very grateful to have a collar returned. And if it is a legal animal otherwise, it is still legal with a collar on. However, it is a disappointing when a study animal dies for ANY reason. It is a huge amount of work to capture animals alive, without hurting them. Losing the animal can mean the loss of valuable data that is used to better understand and manage populations.
So if you have the choice between a marked animal and an unmarked one I would encourage you to harvest the unmarked one. The type of data gathered from tagging animals is generally not harvest data.
They are generally two types of collars out there - VHF radio and GPS collars. VHF collars just emit a radio signal beep that we can find using a directional antenna, where GPS collars record their location. Some GPS collars upload to a satellite, some have to be recovered to record the data. The collars on big game typically have a batter life rated in years, so of the bigger ones can last close to ten years. Some of the relatively small collars you might find on something like a sage-grouse can last 3 years.
Edited to add: If you do harvest an animal with a collar, someone was and is still going to be out there looking for that animal. Returning the collar can save someone a huge amount of time and PITA looking for a animal that is not there - those VHF collars are not easy to find once the leave the general area they were once in. You don't really even have to return it - just call the Division of Wildlife - someone will be grateful.
Last edited by UtahGrouse; September 6, 2012 at 11:03 PM.