>> To better understand the stresses on these migratory species, scientists at Lighthouse Field are testing a new ultralight radio tag. Weighing less than a tenth of a gram, these tags, when placed on butterflies, can passively ping Bluetooth- and location-enabled cellphones of anyone nearby.

They put a solar powered tracking tag on a butterfly...

Then made an app and gamified it to get people to use their phones to collect, track, and upload the processed monarch migration data. It's like Pokemon Go meets SETI@Home for butterflies.

https://www.youtube.com/watch?v=c8ZyJn6BENc

https://swmonarchs.org/ProjectMonarch.php

https://celltracktech.com/pages/project-monarch-press-releas...

A related project, but for birds - https://motus.org

Motus is a distrbuted network of ground stations for tracking birds and other species (like bats!) for research - they also use CTT tags for tracking (along with tags from another company called Lotek - https://www.lotek.com)