Installing a Marshall Telemetry Track Pack on one of our barn owls today. This is the fourth Track Pack install this weekend! There are a lot of different ways you can put telemetry on birds and not all birds fly with it. Our birds use either tail mounts, which they molt out every spring, or Track Packs, which are these little backpacks that are virtually permanent. They disappear into the feathers and you can hardly see them! Scout here is being a very good bird about getting his put on.