Studies that document when and where animals move significantly contribute to our understanding of fish and wildlife on local, national, and even international scales. And while today’s ability to map an animal’s movements through time is visually hard to beat, the data behind the map wouldn’t exist without a series of questions and technological advances that began more than 200 years ago.
Since one of the first documented migration experiments in North America in the early 1800s, this field of study has moved from threads being tied to the legs of eastern phoebes to packages of location data being digitally transmitted from tagged animals and displayed on interactive maps.
One product of the latest tracking revolution, the Motus Wildlife Tracking System, was launched in 2013 and builds on the decades-long concept of radio telemetry in which a small transmitter is attached to an animal and the transmitter’s signal is detected by way of a receiver with an antenna. But where traditional radio telemetry relies on a person going into the field to physically track the tagged animal, Motus is much more automated. Its network of receiving stations automatically logs the signal of any Motus-tagged animal that passes within a station’s detection zone. Those detections are then displayed on an online dashboard.
Tracking Wildlife in the Sooner State
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Tim Patton/Southeastern Oklahoma State University
Research teams from Southeastern Oklahoma State University have used traditional radio telemetry to locate tagged American alligators at Red Slough Wildlife Management Area.
In Oklahoma, wildlife studies have used multiple forms of telemetry technology. Classic examples include research teams hiking up sand dunes to track northern bobwhites in western Oklahoma or slogging through wetland units to locate tagged juvenile American alligators. More advanced projects on greater prairie-chickens and bald eagles have used satellite telemetry, in which satellites – not people – detect the location of the tagged animals. Unsurprisingly, these tech-heavy projects come with higher overhead costs but often require less time in the field and yield more precise data.
Now, researchers from anywhere in the world can use the automated telemetry of the Motus system to track tagged animals that travel near an active station. While Motus projects are limited to the size of the network – location data isn’t available in areas without active stations – they can have lower costs and can shed light on species that spend a lot of time in Oklahoma, like Mexican free-tailed bats, or those that only pass high above the state during migration, like the red knot.
“The Motus system can tell us where a bird, or any other tagged animal, was detected in migration,” said Jeremy Ross, assistant professor at the University of Oklahoma with the Oklahoma Biological Survey. “We can receive a huge amount of data for the tagged individuals, and that data is all freely available to the public.”
Ross has installed multiple Motus receiver stations in Oklahoma, with the latest installation at the University of Central Oklahoma’s Selman Living Laboratory, located in northwestern Oklahoma’s Woodward County. While the primary hope of this station will be to track the seasonal arrival and departure of tagged Mexican free-tailed bats to a nearby cave, the station will log any tagged animal that passes within a 12.5-mile radius.
The Selman Living Laboratory recently joined the international network of 1,700-plus receiver stations that detect animals tagged with the Motus Wildlife Tracking System. More than 40,000 animals representing 327 species have been tagged to date.
“My colleagues in Montana have deployed Motus transmitters on 99 Sprague’s pipits, and it’s possible some of those birds could be picked up at this station,” Ross said. “And while there’s not a lot of shoreline in the immediate area, tagged shorebirds like willets could still be racing through during migration.”
The station at the Selman Living Laboratory may be new to the Motus network, but the tower’s hardware and four of its eight antennas – operating on the “legacy” frequency of 166.38 MHz – have a history with the tracking system.
“This particular set up was first used on the coast of Texas. It had served its purpose there, so when the Smithsonian Migratory Bird Center decommissioned the tower, they donated it to the Oklahoma Biological Survey at the University of Oklahoma.”
Four smaller antennas are also included in the Selman array and will operate on the “digital” frequency of 434.0 MHz. Funding for those antennas was provided by the University of Oklahoma.
“This dual mode operation is a bit like comparing AM and FM. The two systems are using different technologies, but both have the end goal of tracking animals.”
Explore the Motus Data Dashboard, view receiver locations, or check out interactive tracks of tagged animals at motus.org.explore.
The next Wild Side newsletter, as part of Bat Week, will offer more about the project tracking Mexican free-tailed bats using the Motus network.
Tim Patton/Southeastern Oklahoma State University
