08/21/2026
We recently recaptured two Swainson's Thrushes at MPG Ranch that we had tagged with Motus transmitters back in 2024!
🌎 Swainson’s Thrushes don’t seem to breed at our MPG banding station, but show up in this riparian habitat in late summer. Taking advantage of the abundance of food and thick cover to fuel for migration and stay safe during their big annual molt. It never ceases to amaze us how these ~30 gram travelers can navigate the hemisphere year after year to complete their life cycle! 🌎
First slide: We’d captured this bird twice before at this station, 9/3/24 when we tagged it and then again 8/13/25 when we determined that the tag was still functioning and left it deployed. Between those two captures, this bird had – at a minimum – flown all the way to Costa Rica and back! Some interesting tidbits from a quick look at the data:
🧭 It took this bird about a month to get from MT to Costa Rica, this epic journey included 500-mile nonstop flights over open water of the gulf.
🧭 The following spring, it was first detected in the US in coastal Texas and made it back to the Bitterroot Valley in 19 days from there.
🧭 All 3 captures of this bird were in two nets that are within 20 meters of each other! Site fidelity (or site faithfulness) is more typically related to breeding and wintering sites, but these birds appear to have high site fidelity for molting grounds 🤔
We checked the Motus data during this capture (8/4/26), determined that the nanotag was no longer functioning and removed it to release the bird unburdened 🫡
Second slide: We first captured this bird around the same time of year way back in 2021 when it was identified as a hatch-year! Upon recapture in 2024, we fitted it with a Motus tag and tracked it all the way down to at least central Colombia during that fall migration! 😲
Motus towers tracked its return to MT via the gulf coast the following summer. We got one more migration track in fall of '25, with the last detection, Oct. 10th, near Veragua Rainforest, Costa Rica.
During this year's encounter, we were able to liberate this now 5-year-old bird of its harness! 🫡