CAS-supported Range-wide Wood Thrush Motus-tagging Project Starts Strong

by Sarah Kendrick, Migratory Bird Biologist, USFWS

 

*Author’s note: Hey Columbia Audubon Society! I wanted to share a summary of the 2024 Range-wide Wood Thrush Motus-tagging Project since your chapter and many other Missouri birders helped support this project.

The Wood Thrush (Hylocichla mustelina) is a medium-sized songbird of eastern deciduous forests that is known for its flute-like, ethereal, ee-oh-lay song that echoes through our shady Missouri forests. This thrush is an iconic bird of eastern forest that also acts as a flagship species for full annual cycle conservation work in the Neotropics, as the Wood Thrush requires mid-elevation forest structure that is also needed by many other forest-breeding migratory songbirds. I know I’m not alone in saying that seeing and hearing this bird is always a thrilling experience.

The Wood Thrush is a priority species for conservation in 25 U.S. states’ State Wildlife Action Plans and holds threatened status in Canada. Improving our understanding of the ecology of this species’ full annual cycle is essential to better understand conservation needs throughout its full range and to improve the design of targeted habitat management actions. With all those factors in mind, an international group of bird-conservation partners have initiated a hemispheric Motus-tagging research and conservation project across the Wood Thrush breeding and nonbreeding ranges to better understand migratory connections, routes, timing, and survival across the full life cycle. While this project is being co-led by the Midwest’s U.S. Fish and Wildlife Service’s Migratory Bird Program with international partner SELVA, to say this project takes a village (or a few villages), is an understatement.

In spring 2023, I approached state wildlife agencies via Nongame Bird Technical Sections of the Mississippi and Atlantic Flyway Councils, asking if they were interested in being part of a large-scale research study on Wood Thrush. The project goals were to tag the species with Motus Wildlife Tracking System (hereafter Motus) tags across their breeding range in the eastern U.S. in partnership with Colombia conservation organization SELVA, who would Motus-tag the birds across six countries of their wintering range. The pitch was that if states or organizations could raise the funds in their state for 25 tags and help coordinate the deployment of those tags on Wood Thrush in their state using permitted experts, I would handle the coordination and logistics of the project and we could do something really big and unprecedented to learn a lot about this species together.

To my surprise, many states and Ontario signed onto the project to participate! Partner SELVA and I wrote a common (and required) project protocol to ensure that all project partners were using the same field methods, Motus tags, attachment harnesses, and bird-handling permitting process. Our U.S. Fish and Wildlife Service Migratory Birds unit hosted a Wood Thrush Motus-tagging training for project participants in Kentucky, hiring tagging trainers from Willistown Conservation Trust in Pennsylvania and Birds Caribbean, in partnership with the amazing Kentucky Game and Fish staff. Biologists and researchers from state agencies and organizations gathered from 7 states to learn how to safely fit birds with Motus tags.

As of late July, project partners across the eastern U.S. and Ontario have deployed 563 tags on Wood Thrush across 26 states and Ontario! This makes our project the biggest Motus project to date, and it’s only just begun. Partner SELVA will deploy over 100 Motus tags in Mexico, Belize, Guatemala, Honduras, Nicaragua, and Costa Rica this winter 2024-25, and a second year of breeding-season tagging will occur in 2025.

What makes this Wood Thrush project different is not only its size and scope (though those are amazing features), but we asked partners to deploy their Wood Thrush tags on birds within range of an active Motus station. This will allow us to test detection ranges and gather data on local movements of prior to migration. Wood Thrushes can also hold a Motus tag with a battery that lasts over a year, so hopefully we will gather return detections of the birds as they arrive back on territories next spring. Site fidelity, or returning to the same breeding territory year after year, can be high in this species for older birds (3-5 year old). We do hope to see detections of returning birds to investigate inter-annual survival, which has not been well studied in this species.

Thanks for your support of this project!

Quite a few aspects of this project are providing proof of concept, including unique funding streams. One of those funding streams came from birding groups in Missouri, including Columbia Audubon Society. I extend much heartfelt gratitude to the leadership and members of CAS, Missouri Birding Society, Burroughs Audubon Society, and the Jungbluths for helping to fund our state’s portion of the Wood Thrush Project. Huge thanks to the Missouri Department of Conservation (MDC) for funding support and partnership, especially that of Kristen Heath-Acre; and thank you to the Missouri Conservation Heritage Foundation for providing a donation portal for the project. With our bird community’s support and the assistance of many volunteers and colleagues in the field, we were able to deploy 48 Motus tags at seven sites across Missouri.

So keep your eyes peeled when you encounter Wood Thrush this fall – you may just see a Motus tag on its back.

For more information on the Motus Wildlife Tracking System, visit: