You may recall that I reported last year on a bird banding project that GMI is supporting. To recap, MOTUS is a program for deploying automated receivers across the country to pick up coded signals from bird tags. 

We are providing technical support to the Northeast Motus Collaboration (#48) and your scribe is acting as a volunteer technical advisor to this group.  There has been extensive bird tag testing at Marshlands with field tests and also drone missions. 

A technical report has been published where we compare two Motus-compatible tags: The NanoTag and the LifeTag/PowerTag. The “NanoTag” is manufactured by Lotek and has been widely used by researchers using the MOTUS system since the beginning. The LifeTag technology was developed by Cornell University, and has since been licensed to Cellular Tracking Technologies (CTT) from which they have developed the CTT LifeTag and CTT PowerTag. These tags demonstrate greatly improved performance in both detection distance and code identification.  The LifeTag is solar powered and will run forever as long as the sun shines whereas the PowerTag is powered by a tiny battery which works for birds that prefer to travel at night.

We have tested a number of samples of each tag variant and the LifeTag and PowerTag far out perform the NanoTag in detection distance.  The NanoTag is detectable only to about 0.5 km whereas the CTT tags have been detected out to 8 km on tests at Marshlands.  Some recent tag detections have been as far as 40 km over water.  This difference in performance is probably due the higher operating frequency (434 MHz) of the CTT tags compared to the NanoTag (166 MHz) which makes the tag antenna more efficient. The improved coding system provides a better signal to noise ratio which also increases detection range.

For those of you who are interested in the technical details here is a link to the test report.  We are also home to one of over 375 automated receiver systems across the globe.