Thu. Feb. 1, 2018

by Eric Reuter

Editor’s note: this story was updated on 2/8 to reflect several suggestions for clarifications from Sarah Kendrick.

Rapid technological advances are allowing us to track bird movements more effectively than ever before, creating new ways to understand and appreciate migration and behavioral patterns. At the January CAS meeting, attendees were treated to a fascinating talk by the Missouri Department of Conservation’s State Ornithologist Sarah Kendrick about how modern tracking methods are informing and inspiring new research.

Understanding the spatial patterns of avian behavior can increase our understanding of everything from local habitat choices to continental or global migration patterns, including identifying areas of highest conservation concern. Tracking technologies fall into several categories, including:

  • Banding – The physical attachment of a identifying band to birds allows for very precise location and physical data, but only if the bird can be recaptured. However, the low recovery rate of banded birds is an obvious limitation.
  • Radio or satellite telemetry –  Tagging birds with transmitters allows them to be tracked at various scales, depending on the strength of the transmitter. This can involve direct tracking using a hand-held antenna (for monitoring animals at smaller scales) or a vehicle-mounted antenna (for tracking animals across large landscapes), such Allison Cox’s work on the natal dispersal of Red-Bellied Woodpeckers. Larger birds can be tracked using GPS-equipped tags, as in some research by MU’s Mitch Weegman on White-Fronted Geese.
  • Geolocating – These tags record ambient light conditions experienced by birds; the data can then be used to calculate the lat/long position of the bird for every data point. These are particularly helpful for tracking migratory movements, but like banding, require recovery of the bird (and tag).

The heart of Sarah’s talk focused on a very exciting new development in bird tracking technology: the use of “nanotags” in the Motus tracking system recently developed by Bird Studies Canada and its partners. In this system, birds are fitted with very small radio transmitters that each broadcast a unique symbol; these tags are light enough to be used on insects like Monarch Butterflies and dragonflies. However, rather than attempting to physically track these transmitters, Motus has set up a network of automated detection stations in North, Central, and South America. Whenever a tagged animal passes within range of a given station (~15 km radius), the event and any relevant data are automatically recorded; see this graphic for an example. With enough stations (Motus now has over 300 in various strategic locations), a vast array of useful movement data can be collected on birds and other animals too small for GPS tracking. This short video introduces the Motus concept:

The Motus website provides various demonstration maps that animate the tracking data collected by the system. If you open these, be sure to make sure the map begins playing; if it does not, you’ll wonder why nothing is happening. For example, one animation shows the movements of Grey-cheeked and Swainson’s Thrushes from South America to Canada in spring 2016.

Studying the video (or other graphics), you may note a significant gap in the station coverage; although Motus stations are strung along the United States’ Gulf Coast, East Coast, and Great Lakes, there are few stations in the Midwest, especially west of the Mississippi River. As part of her talk to CAS, Sarah expressed her strong desire to work toward establishing two lines of Motus stations across northern and southern Missouri. These towers require little more than power and internet connections, and are estimated to cost $5,000–$7,000 each, quite cost-effective given their long life and the relative expensive (and loss rate) of fancier tracking tags.

Her goal is not only to plug the gap in our knowledge of Midwestern migration patterns, but also to draw new research and researchers to Missouri. For context and comparison, she described how Pennsylvania is working to install two lines of Motus towers offering complete coverage along the Lake Erie shoreline and across the entire state from northwest to southeast. In Missouri, a network of stations could be sponsored by a combination of government grants and private or non-profit support; any given organization or business could sponsor one or more towers as a contribution toward the final goal. If you are interested in supporting this effort of placing Motus stations in Missouri, donate to the Missouri Conservation Heritage Foundation by choosing “Other” for your chosen project support, and type in “Wildlife Tracking Motus Towers”.

New technology is allowing ever-better methods for understanding birds and their interactions with our increasingly human-dominated landscape. CAS is very grateful to Sarah for taking the time to speak to our group and offer her exciting vision for the future of ornithological research in Missouri.