Iowa joined other Midwestern states, and researchers in Canada and Central and South America to create a network of radio receiver stations to learn more about the long-distance migration patterns of birds, bats and insects.
The Motus Wildlife Tracking System, motus being the Latin word for movement, began in 2013 by Birds Canada near Toronto. Motus is a system of coordinated automated radio telemetry station used to track long-distance movements of small animals.
Automated antenna array connected to radio receivers are being installed throughout the Western hemisphere and birds, bats and insects are netted and trapped then outfitted with small tags that emit a radio signal every few seconds. When the tagged animal passes near a receiver station, it records the tag and identifies the animal to which it was attached. So multiple detections over time can build a map of migration for a tagged individual.
Iowa is an important flyway for migrating birds and as the state works to fill in its east-west radio receiver station fence, more birds will be detected providing more information on migration patterns that can inform conservation decision making.
“We’re trying to increase the number of stations in Iowa and the Midwest to benefit current and future research,” said Anna Buckardt Thomas, avian ecologist with the Iowa Department of Natural Resources (DNR).
Iowa began installing stations in August 2021 as part of a Fish and Wildlife Service Grant that funded equipment for 40 stations in the Midwest and a dozen in Central and South America. The Iowa stations are located in areas that met elevation requirements and were placed on buildings owned or leased by the Iowa DNR, including at Lewis and Clark State Park, and near the towns of Early, Boone, Swisher, McGregor, Wapello, and Burlington.
“We are planning to install one more station this fall, and once our partners install their stations, we could have a dozen up and running in Iowa, collecting data, then we could begin to ask our own questions, do our own tagging research while still contributing to the larger, hemisphere-wide migration effort,” she said.
Stations cost about $4,000 each, are designed to fit the site and expected to last for 10 years. The requirements to host a site is, its location in relation to other stations, elevation in the surrounding area, and an internet connection.
The stations are automated and have four antennas set to receive two radio frequencies. The larger antennas have a detection range of 15 kilometers, the smaller antennas can cover 10 kilometers. Once the system is installed it is fairly low maintenance and is always on and ready to detect tags nearby.
So far, Iowa has had 20 detections, including eight different bird species and at least one detection by six of the seven stations. The station near the town of Early, on the Blackhawk Wildlife Unit building, has had three detections – a lesser yellowlegs tagged at its wintering grounds in Columbia; a golden-winged warbler tagged at its wintering grounds in Costa Rica; and an American kestrel tagged on the breeding grounds in Minnesota.
The lesser yellowlegs was tagged in Columbia on April 19. It was detected in southern Costa Rica on May 4 traveling an estimated 78 kilometers per hour (48.5 miles per hour), then was detected in Kansas on May 7, then again on May 7 at the Missouri River Wildlife Unit for two minutes, then at the Blackhawk Wildlife Unit for five seconds.
“All that information is fed into one database so we can detect animals that were tagged by any other researcher in the database, and they will be able to detect any tags we put out in the future. We’re adding an interesting and vital piece to the story of these birds,” Buckardt Thomas said.
Information on the project is available to the public and can be seen at motus.org. The stations are automatically updating the database so the data on the website is always current.
While Iowa hasn’t started tagging animals yet, that is the next step once more stations are up and running. Tagging birds is regulated by the Bird Banding Laboratory with the United State Geological Service that outlines specific requirements and limitations associated with bird tagging and authorizes required permits to avoid negatively impacting the bird’s life.
“We have a much better chance of detecting a tagged bird than to recapturing a bird that is only banded,” she said. “We will learn a lot about the birds’ migration routes and timing when they move through the area, and which Iowa habitats they are using.”