Each bird we handle, we add two small pieces of jewellery. Both are thin metal bands that wrap loosely around their lower leg. One is a plain silver-coloured leg band that has a unique serial number engraved on it. The second leg band is coloured with a unique combination of large letters and numbers that can be seen from a distance or through a spotting scope. The National Banding Office keeps track of the band numbers and colour combos.
I encountered this pair of Ferruginous Hawks during our spring reoccupancy surveys. They were hanging out on a distribution line, in a territory that was occupied two years ago. Looking through a spotting scope, it looked like the male (the smaller hawk on the left) was wearing a leg band, but he was too far to read the band through my spotting scope. Instead, I took a photo using a telephoto lens and then zoomed in to read the band. Black 7 over S!
Resighting a band on a live bird is a rare event. Imagine writing your name on a ball and throwing it back into a huge ball pit at a play park. Now go find it. You could spend a very long time looking for it and it’s possible that you never see it again.
But finding a banded bird again can provide valuable information. If you banded it as a youngster, you will have age, where it was born, and the where it lives now. Sometimes birds are found during migration, providing important information about their migratory timing and pathway.
Male Black 7 over S was banded as an adult in 2012. He was captured in order to attach a short term satellite transmitter that was designed to fall off naturally. We collected data from the transmitter for several weeks during the breeding season, until the battery quit as planned.
Resighting this male is interesting in several ways. 1) He has returned to his original home range with a potential mate. We’ll keep an eye on him this summer to see if he nests. 2) He is no longer wearing his backpack transmitter, which makes us feel good that he doesn’t have to carry his transmitter anymore.
Our project has banded nestlings for specific research objectives too. Each year, we wait to see if any bird can be re-sighted by our group, other biologists, and citizen scientists.
Keep checking back for posts about our satellite tracking, juvenile life after leaving the nest, and banding.