By Teresa Wicks, Portland Audubon’s Eastern Oregon Field Coordinator

In the 1950s wildlife biologists first explored the idea of using acoustic signals to track wildlife, though it wasn’t until the 1960s that radio transmitters were successfully deployed. Historically, tracking wildlife through radio telemetry required trekking through underbrush, over rough terrain, or taking an airplane flight, in an attempt to get a handheld receiver antennae to find, and triangulate, the radio signal being emitted from an animal fitted with a backpack, collar, or other devise. Over the past few decades, automated radio telemetry (ART) has become increasingly popular.  With ART, stationary retrievers record radio signals emitted by wildlife fitted with radio transmitters. Data are collected by computers, which allows for more data to be collected than with traditional, handheld receivers.

While the move to ART has allowed for increased data collection, it brought about a different kind of problem, particularly for wildlife that move long distances, like many bird species. Automated radio telemetry requires that the radio transmitter fitted individual pass close (often less than 10 miles) to a tower. While many automated programs exist, collaborating on those programs isn’t always easy. That is, until the Motus Wildlife Tracking System (Motus) was created.

Motus is a global network of researchers using automated radio telemetry to monitor birds, insects (like butterflies), and bats. Individuals that are fitted with nano radio tags (nanotags) for a project in one region, will be recorded by all other Motus towers that they pass. Their information is recorded by the tower, and processed by Motus, sending all data on to the project lead.

To make the Motus system as effective as possible, requires towers to be distributed across the landscape. These towers consist of antennae that look a little like television antennae and can be attached to buildings or set up free-standing in more remote areas. Until a few weeks ago, there were no Motus towers in Eastern Oregon. But, with the addition of two towers at Malheur National Wildlife Refuge this is no longer the case.

These Motus towers not only allow for USFWS staff and partners to start their own Motus nanotagging projects but also allows for Malheur to support diverse research projects happening throughout the Pacific Flyway and the region. Two such projects in the Pacific Flyway are the Pacific Shorebirds project and the BC Interior Thrushes project. The Pacific Shorebirds project aims to track shorebirds during their migration in the Pacific Flyway. Oregon’s one coastal motus tower in Bandon read the tag of a Western Sandpiper that was tagged in BC. Their tag was then read in Colombia, Quebec, Maryland, and most recently (November 30, 2021) in Baja California. Now with motus towers at the north and south end of Malheur, we’ll know if this individual Western Sandpiper made a stop at Malheur while on their way from Bandon to Quebec.

The BC Interior Thrushes project is designed to understand the migration paths and habits of Swainson’s Thrushes found in a sub-species hybrid zone in the Interior BC. One thrush tagged as part of this project was recorded at the motus tower in Bandon and again at Mackay Island NWR in North Carolina. The predicted flight path indicates that this Swainson’s Thrush could very well have been a visitor to Malheur HQ this fall.