Working with three ranchers and a vendor of animal-tracking systems, the state last month wrapped up a pilot test that involved tracking animals using passive RFID tags. Now the state is looking to launch another test with active RFID tags, which will hopefully extend the tracking range, said Scott Leach, a field investigator for the Colorado Department of Agriculture. Active RFID tags are battery powered and can send out a signal at predetermined intervals. Passive tags only transmit data when scanned and tend to have a smaller range.

As part of his job, Leach tracks chronic wasting disease (CWD), a degenerative neurological illness endemic in Colorado and some other states. CWD is viewed as a very serious threat to both captive and wild cervids -- elk and deer -- and the state wants an automated system to track and isolate any CWD outbreaks to protect elk herds.

The system must also meet federal National Animal Identification System (NAIS) specifications. The NAIS has been promoted by the U.S. Department of Agriculture since 2003 as a way to automate the tracking of cattle and other animals infected with mad cow and other diseases.

Among the NAIS stipulations is that each animal have a unique identification that will allow it be tracked from place to place, said Leach. The RFID tags must also be affordable to ranchers, and must be able to track the animals over a wide area without causing them injury. Although the state is still investigating the technology, Leach said RFID is the preferred tagging method. If the agency finds that such a tracking system works well for the elk and deer populations, it may use RFID tracking for other species, such as range cattle.

To start the process, the state in late 2004 tagged a herd of 130 elk in a pilot rollout using an identification system from Calgary, Canada-based Advanced ID Corp., which makes RFID and animal tracking systems. According to Leach, the pilot went well, with handheld readers able to get test results from the elks' ear tags from a distance of up to eight feet. He acknowledged, however, that the percentage of elk that came into range was low, and he said there are plans to launch another pilot in March using active tags. No vendor for that project has yet been selected, Leach said.