|Longshot, pictured here during his recapture in April 2015, wearing the geolocator that he had carried since the previous July.|
But in order to learn even more about the migration of this imperiled bird, we deployed eight more geolocators on Prothonotary Warblers earlier this spring. Below, we'll describe the process for attaching these miniature tracking devices to these birds. On our next post, you’ll get to meet the eight special birds that we need your help finding next spring.
|Eight light-level geolocators arrive at Beidler Forest in May 2016. Learn how these devices work here.|
In order to attach a geolocator to a bird, harnesses are made using Stretch Magic (a common type of jewelry cord). Harnesses are tied in a knot creating two loops, and then precisely measured in order to fit around the legs of a Prothonotary Warbler. Once each harness is accurately measured, they are superglued to the geolocator.
|After the knot is tied, each loop must be accurately measured to a specific length. If the length of the loop is just one centimeter off, the harness might not fit the bird correctly.|
|Once the glue dries, we trim off the excess cord and the geolocator is officially ready to go!|
Now that are units are ready to be put out, we strategically choose the best candidate Prothonotary Warblers out of those that we've color-banded in the past. This is one of the most important reasons we color-band: since we can use the bands to identify each bird uniquely, we can monitor their return rates and breeding success. From this data, we can determine which of our birds have 1) migrated in past years and returned to Beidler and 2) successfully bred this year. These two factors often influence an individual's likeliness to return in subsequent years, and thus are good metrics for determining which birds to use in this project.
With that in mind, the photo below is a quick overview of the band colors that we've used over the last three years. That way you can learn the colors of each bird carrying a geolocator and you'll be ready to help us find them next spring!
Contrary to what you might think, the harness and geolocator do not go over the birds' wings (although sometimes we call it a backpack); instead, they go over the legs and each loop rests up near the bird's hip.
|Putting on the first geolocator.|
In our next blog post, we'll introduce to you the eight Prothonotary Warblers that received geolocators in 2016 so that you can join us in looking for them next year when they hopefully return to Beidler Forest!