Sharing this work brings me immense joy and would be impossible without my coauthors @bvdbirds.bsky.social, @aladino123.bsky.social, Nick Bayly, John Bates, Wilmer Ramirez and especially Adriaan Dokter who has been a world class mentor and collaborator. Can't wait to see where our work goes next!

Given the weak link between wind support and nightly migration at our study sites, predicting high-volume migration events to target for conservation action such as lights-out initiatives may be harder in tropical cities like Bogotá, Medellín, and Calí 🧵9/10

Our findings also build on an emerging picture of how flyways are structured in Colombia. We found the highest volume of birds funneling through the Magdalena Valley in fall as birds aim for the Andes as an overwintering destination and for destinations deeper into South America. 🧵8/10

It's spectacular to see birds flying 3000 m above the Amazon when headwinds headwinds are closer to ground level as seen in this week-long profile from Guaviare. Check out the switch in altitude with the wind! These switches drive the migration pulses we see during spring in the Orinoco Basin 🧵7/10

Wind support may not drive which nights birds choose to migrate but does play a big role in altitude selection, especially when navigating spring headwinds 🧵6/10

Since it doesn't pay to wait for optimal conditions nightly variation in the volume of migration is also much lower in Colombia. I.e. more than twice as many nights are needed to capture half of the total seasonal migration in the Magdalena Valley than in Illinois. 🧵5/10

Vertical profiles of wind support across height highlight just how much more variable wind is across altitude and between nights in Colombia than in Illinois, USA. Wind at our study sites in Colombia is similar across the year but in Illinois looks like a bowl of spaghetti! 🧵4/10

Wind helps birds travel huge distances while conserving energy which is a big part of why cycles of warm fronts and cold fronts drive the nightly volume of migration at temperate latitudes. But how is wind relevant for birds in the tropics, where weather operates at a much finer spatial scale? 🧵3/10

You can find the paper here or on my Researchgate, and read on for details! 🧵2/10

royalsocietypublishing.org/doi/10.1098/...