Bobolink Odyssey 2021
From May 20 to July 17, 2021, I worked with an incredible team of four other students led by Dr. Noah Perlut to collect data on Bobolinks and Savannah Sparrows in Shelburne, VT. This project's original goal was to assess the breeding success of grassland birds in various management strategies for hayfields and pastures. However, after two decades of continued research, many other sub-projects have been undertaken. Throughout the season, we worked to capture and band over 600 individuals. Approximately 46% of these birds were adults returning to breeding grounds and the other 54% were nestlings that were banded throughout the season. In order to work with the young, we found and monitored over 125 nests of these species. The first week of the season focused on mist netting at each field we would be monitoring. We hoped to capture the majority of the adult birds in these fields to record morphometric data on returning individuals. We also wanted to apply color bands to as many new arrivals as possible so that they could be identified throughout the season from a distance.To ensure that we were ready to start capturing birds first thing in the morning, we arrived at the fields at 4am - about an hour before sunrise. This allowed us to set up the mist nets without too much disturbance to the birds and without making the position of the nets too obious. The low light also makes these nets nearly invisible, so it was important to have them open when the incidence of capture would be the highest.
While the goal was to capture Bobolinks and Savannah Sparrows, having mist nets open for long periods of time resulted in some interesting bycatch. While it must not be fun to get tangled up in a net while going about your daily business, we monitored these nets constantly, so all birds were quickly freed and any non-target species was immediately released.Some birds, such as Red-winged Blackbirds were quite common to find in the nets while others, such as the Swainson's Thrush and American Redstart seen below, were surprising finds! We even had an encounter with a family of Wild Turkeys!
Of course, we were also successful with catching many Bobolinks and Savannah Sparrows. Between the adults and young we collected data on throughout the season, it was nearly a perfect split between Bobolinks and Savannah Sparrows.
After the first week, our priorities shifted towards nest searching. It really is like looking for a needle in a haystack to find a small nest woven out of grasses somewhere in a vast field. Every once in a while we'd get lucky and flush a female from her nest while walking through the fields. It was easy to tell when a flushed bird was on a nest or not. Incubating females are very protective and only fly when danger is less than five feet away from them. For that reason, we always carried long sticks to push the grass ahead of us while we walked through the fields. This would give incubating mothers a heads up of our presence and decrease the risk of us accidentally stepping on a nest.While it was always a nice surprise to find a nest accidentally, most of our success came through patient observation of specific birds. The first clue that you are near a nest is if a pair of birds start chipping agressively. From there, it can be helpful to note whether the birds are flying far from you as you approach or only making short flights, staying within the same general area. Then it's best to step back until the birds stop focusing on you. Watching them consistently fly to the same spot is a good sign that there's a nest there. Even better if they're carrying food, and essentially a guarantee if they emerge with a fecal sac. Nestling waste is deposited in a sac that the adults can pick up and drop outside of the nest. This helps maintain the hygiene of the nest. 
The young birds grow quickly, and by the time they’re six days old, they’re ready to be taken out of the nest to collect some data. Six days old is the target age because they are old enough to withstand some handling and time out of the nest, but are still too young to have already left the nest. When collecting data, we moved the birds away from the nest to ensure that the grass directly around the nest wouldn't get matted down. The chicks were then weighed, banded (with just one metal band), and a blood samples was taken from a vein near their elbow.
Once the nestlings were between nine and eleven days old, they were ready to fledge! In general, survival rates are lowest in the first year of these bird's lives, so it was rewarding to see clumsy, stump-tailed fledglings flying around the fields at the end of the season!
After the young leave the nest, they still rely on the parents to feed them for about another 1-2 weeks. Adult female Bobolinks make a distinctive call when you get near recently fledged chicks. This was another rewarding sign after monitoring a nest!When I wasn't catching adult birds, searching for nests (which was essentially constant), or banding nestlings, I spent most of my time resighting adult birds. While the color bands are quite obvious up close, it can be a tricky task to accurately identify them as the birds hide in the grass and refuse to show themselves. The main reasons for resighting these birds is to assess their dispersal throughout the different fields at Shelburne Farms, determine if the parents feeding young are the biological parents, and to keep track of the age of returning individuals.Spending countless hours walking through fields over the summer brought some other unique encounters in addition to our project's goals. Everything from flushing a Wild Turkey from it's nest (a truly terrifying experience) to finding a fawn curled in the grass, there was a new experience to be had every day. A Blue-spotted/Jefferson's Salamander walking through the field was certainly a surprising find by one of the other technicians! While some of it's features (conical tail, dark body color, relatively narrow head, blue flecking on sides) are more consistent with Blue-spotted Salamander, it is almost impossible to differentiate the species without genetic testing where they overlap due to abundant hybridization.
Working on this project was an incredible experience that I am extremely grateful for. Apart from all the intimate ecounters I had with Bobolinks, Savannah Sparrows, and others, I got to work with an amazing team and a fantastic leader. I gained invaluable field experience, strong connections with the birds and landscape, and many friends.If you would like to learn more about this project's goals or browse the many publications that have come from the 20+ years of the Bobolink Odyssey's operation follow the links below.