Tracking the Louisiana Warbler
Can you see the tiny clear antennae sticking out from between his feathers, that is the geolocator
A bird smaller then your fist will fly over 4000 miles in the next year as part of it’s normal routine. Understanding how it does that, and how all the other members of its species do it is hard, but also really interesting.
One of my favorite parts of being a bird bander is getting asked to come out and help other people with their projects. I have had many marvelous mentors and I love having the chance to pass it down the chain.
A few weeks back I was invited to come out and help capture Louisiana Waterthurshes and put geolocators on them.
Geolocators are small devices that record light levels as the bird migrates and we can use the day length information recorded to determine the latitude the bird was at on a given day. It’s not the same as strapping a GPS to something, but it lets us study the migration of small birds who can’t carry bigger loads.
Catching waterthrushes was a lot of fun, they are a medium sized warbler that live along mountain streams here in Arkansas, so we set up the mist nets across the streams and put out speakers to draw in the males who are defending their territories. We targeted males because they have higher site fidelity. So if this bird returns next year he is more like to come back to this particular stream then his mate is. We have to recapture each bird and download the data from the geolocator so we need to be able to find them again.
After capturing the bird we carefully attach the geolocator so it sits low on his back, just above the tail. We use a small harness which wraps around the legs, but doesn’t prevent the bird from flying or moving in anyway. The device is so small almost all of it is hidden under his feathers. All that shows is the little antennae that collects the light. We quickly released him back into the beautiful ozark mountains and hopefully he will return to this same stream next year so we can recapture him and take off the geolocator and download the data.
female Belted Kingfisher
Researchers across the U.S. are putting geolocators on waterthurshes so we can see if birds from different parts of the country are wintering in different areas. Understanding this connectivity is vitally important to the conservation of these birds. Birds are an international resource, they don’t recognize borders, and this makes conserving them challenging because so many people and organizations have to be involved but it is also one of the amazing things about bird conservation.
Accidental catches are always fun as well, got my hands on a Belted Kingfisher for the first time. Check out this feisty female. She was not happy to be caught, but we quickly released her. Kingfishers have small legs, because they nest in burrows in sand banks and their small legs allow them to dig out the burrows and also crawl up and down the burrow to take care of their young. They are one of my favorite birds and it was quite the treat to get one in the hand.
Those waterthrushes are going to spend the summer on the streams around the Buffalo River and then migrate this fall to who knows exactly where and return the next year. It’s amazing to think what this tiny creature will see and overcome as part of the next year, all while carrying a tiny little ‘backpack’ so we can better understand what he does.