Hey everyone, it’s Bri again, and we are in the final stretch of our field season out in the salt marshes of the Eastern Shore. In June, we discussed point counts and ARUs. For this installment of the field blog, I will be touching on mist-netting and bird banding, both of which are within the “rapid assessment” protocol designed by SHARP, and how these techniques are helpful in understanding breeding bird populations.
I want to make special note here that bird safety is our number one priority whenever we conduct mist-netting and banding. All birds that are caught and banded are done so with proper permitting. While it is very interesting to be able to catch birds, we do not condone others doing so without specific permits, training, and qualifications! If you are interested in seeing mist-netting and bird banding, I recommend looking up your local nature centers, as some may have demonstrations available to the public! You can also check out the USGS Bird Banding Lab for more information on the banding process.
Another beautiful morning out in the marsh!
What is mist-netting?
Mist-nets look like large volleyball or tennis nets; but to ornithologists, mist-nets are one of the ways we capture birds to study them. Made out of thin nylon, these nets are made to catch birds, the nets themselves often being difficult for a bird to see, and thus, making it easy for them to fly in. Mist-nets can be set up in any habitat, including the marsh.
If you look closely, you can see the mist-nets we had set up to capture birds!
For our project, six mist-nets are set up at a specified location where we wish to understand breeding ecology. Typically, these nets are set up within 30 minutes before and 30 minutes after sunrise, and are checked regularly (every 10-20 minutes based on weather) by members of the project team. Any birds caught in these nets are safely removed by those trained in mist-netting and bird handling. We are focusing mainly on Seaside Sparrows and Saltmarsh Sparrows because we are interested in their population dynamics. All other species are considered bycatch, and when caught in the net, are removed and released immediately.
What is bird banding?
Bird banding is a tool created to help us individually identify birds and track them through time. When birds are captured in mist-nets, they are placed in a cloth bag and safely transported to the banding station, where a trained bander then takes an metal band stamped with a unique string of numbers. This metal band is then placed on the bird’s leg using specially made tools for banding. Each band’s unique code acts like our fingerprint. If we catch this bird again, we can look up that individual in the banding databases and see when and where it was first captured.
A metal bird band placed on the leg of a juvenile Seaside Sparrow.
Once the band is placed, we take a look at the bird’s physical features. For our project, we are looking at breeding Seaside and Saltmarsh Sparrows. mDuring the breeding season, ale birds will have a “cloacal protuberance” which is the swelling of the cloaca (define cloaca); whereas females will have a “brood patch”, which is the loss of feathers on the belly to help the bird incubate her eggs more efficiently. Both of these are indicators of breeding and help us understand if breeding is occurring at that location in the marsh. Other body measurements are taken during banding, such as wing length, the length of the bill, and body weight. These measurements can be used to answer a number of questions, including the physical differences between males and females or adults and juveniles.
An adult Saltmarsh Sparrow caught during our banding efforts!
For our final blog post, I will be providing a summary of what we saw this summer and how we plan to use this information. Please continue to follow along with the blog on the Marshes for Tomorrow website as well as Audubon Mid-Atlantic’s social media and newsletter for marsh updates!
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