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
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.
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.
As some of you may know I have been working on a technical project to support a program of deploying automated receivers across the country to pick up coded signals from bird tags. I felt they could use some technical guidance from a retired electrical engineer and Ham radio hobbyist (W3ASA) since most of the folks involved are biologists and ornithologists. I have been working with Willistown Conservation Trust who are spearheading this effort in Pennsylvania. They recently received a $500K grant from US Fish and Wildlife which will be used to deploy more automated receivers throughout the mid Atlantic region. My role in this will be to advise on appropriate antennas that will be mounted on towers which will provide good directional information, be cost effective, and relatively easy to install in remote locations.
As part of GMI’s science mission we are supporting a test facility that will enable field testing of various antenna combinations and bird tags. The tags currently in use operate at 166 MHz. Cornell has developed a new tag which operates at 432 MHz in addition to allowing smaller antennas they have orders of magnitude more code combinations than the 166 MHz tags currently in use. We have antennas set up for these tags as well and are currently running tests on them.
Since Great Marsh has been designated as an Audubon Important Bird Area(IBA) it is appropriate that GMI support new technologies that will enable ornithologists and biologists to gather new information that was not possible without the support of this technology. See Motus.org for more information. This link shows receiver locations worldwide and if you zoom in far enough you will see the two Marshlands deployments
Jim Moore, October 4, 2018