This post was contributed by Chrisula Stone, a student at Northern Kentucky University and a 2020 Burtt Undergraduate Mentoring Grant recipient.
I first became familiar with the iridescent, aerodynamic, and well-traveled Tree Swallow (Tachycineta bicolor) as a park volunteer. In 2012, years before I began my second go-round as a 38-year-old “non-traditional” college student, I answered an ad in the local paper that was seeking volunteers to monitor nest boxes in our public parks.
The parks of Kenton County, KY, where I live, have a wonderful series of nest box trails that were established in 1998 by our former recreation programs coordinator, Steve Trauger. In 1998, Steve, with the help of volunteers and the Scouts, established trails with beautiful handmade bluebird nest boxes throughout our parks. The boxes soon attracted not only Eastern Bluebirds, but also other cavity-nesting birds that are native to our region such as Tree Swallows, Carolina Chickadees, and House Wrens, and we now have established populations that return to them every year. I immediately fell in love with nest box monitoring when I came upon this new role in 2012, and it quickly became my favorite hobby. To me, it is just the perfect combination of hiking, birding and science. In 2014, with Steve’s support, I was able to set our nest box trails up as a NestWatch chapter (www.nestwatch.org), which allowed us to create and add to a long-term dataset on our nest box birds and contribute to science. Being a NestWatch chapter coordinator has allowed me to meet new people and form new friendships, and has opened so many doors for me.
I like to describe Tree Swallows as very charming, with a touch of dirt and drama. Their nests are lined with feathers, which they use in their impressive and entertaining courtship displays; Steve would say a clean, white feather was “like a diamond ring to them.” Tree Swallows are great to have in our parks, because they eat a lot of insects, which may be a natural way to keep mosquito populations in control. While they are amazing aerialists and are adept at flying around and catching insects, their bills are ill-equipped to excavate cavities in trees for their nests, so they are reliant on old woodpecker holes or artificial nest boxes for successful breeding. They are quite tolerant of humans fishing, hiking, and playing sports near their nest boxes, so placing a box near a fishing spot or a hiking trail works out well for both the swallows and the people monitoring the boxes.
When I returned to the classroom in 2016, I had to make a lot of adjustments to my schedule and life, but I knew the one thing I was going to keep doing was monitoring my boxes. As is the case when you have something you really love to talk about, my nest box birds came up in conversation with my professors and advisors at Northern Kentucky University (NKU). Over and over again, the people I spoke with suggested that I meet Dr. Lindsey Walters, NKU’s resident behavioral ecologist and ornithologist, who happened to specialize in the study of cavity-nesting birds. Could that really be true? Could there actually be a professor at my university who studies the subject of my favorite hobby? As it turned out, Dr. Walters was teaching a lab I needed to take, so I made sure to do a little bit of “schedule algebra” to ensure I could take her class, with the intent to talk about my nest boxes with her in passing, and to see where it could possibly lead. When I finally had the pleasure of meeting her and speaking with her in 2017, our conversations led to her seeing the nest box trails I was so fond of, meeting the recreation programs coordinator with our public parks, and eventually taking on some of our local park nest box trails as a new research site for her lab. Our new recreation programs coordinator, Rhonda Ritzi, was instrumental in establishing this collaboration. Our beloved Steve had just retired, and Rhonda was just stepping into her new role. During this time of change, our collaboration came together so naturally, and a beautiful working relationship has blossomed over the years, which I could not be happier about.
My research project began as an assignment for the undergraduate Advanced Writing in Biology course that I took in 2019. The assignment was to write a literature review on any topic I wished and come up with a related hypothetical research project proposal. My mind went to several topics, but ultimately, I decided I wanted to stick with the subject I was already familiar with: My nest box birds. However, my wonderful professor for that class, Dr. Chris Curran, threw me a bit of a curveball: She told me I had to pick a new topic, one that I hadn’t already worked on in the past. That meant I had to divert from the studies of avian behavioral and reproductive ecology that were the focus of the Walters Lab, and find something new to focus on.
As I combed through many research articles, I found that there were a lot of studies about the effects of mercury on birds. I happened to be taking a chemistry class at the time, and was fascinated not only by the birds used in these studies, but also by the analytical chemistry they used. I found that one of the nest box birds I was very familiar with —the Tree Swallow—was part of several mercury studies (Brasso and Cristol 2008, Whitney and Cristol 2018). Tree Swallow nests are typically near bodies of fresh water, and adults mostly feed their nestlings prey that was captured within about a 400-meter radius from their nests (Quinney and Ankney 1985). The large number and variety of individual insects fed to each bird contributes to a mercury body burden that may be considered representative of the amount of mercury in the body of water where the insect larvae it ate hatched and fed on microorganisms and vegetation (Wiener et al. 2002). The mercury a nestling ingests circulates in its bloodstream and can accumulate in organs and tissues.
This topic fascinated me, and I put in extra time searching and reading through the literature to come up with a research project proposal for my assignment. The hypothetical study I proposed took a closer look at the suitability of using feathers collected from Tree Swallow nestlings during banding as a biomonitoring tool (Condon and Cristol 2009, Brasso and Cristol 2008, Whitney and Cristol 2018). The results of such a study, I thought, could be used to develop a protocol that could be adopted at a large scale for long-term monitoring of mercury pollution, which was inspired by the NestWatch model I was already so familiar with. When I finished my review and subsequent research project proposal assignment, I shared it with Dr. Walters, who said, “You know, we could actually try to do this study.”
I was so excited and happy to hear that, and I began developing a strategy to execute a pilot study. I had no funding or supplies, and I still had a lot of work to do to figure out how I was going to analyze the samples for mercury. Fortunately for me, the professors at NKU helped me work through these questions. I hit a roadblock when I learned that NKU didn’t have the best equipment for analyzing mercury samples, but Dr. Walters and I were so lucky to be able to partner with Dr. Rebecka Brasso at Weber State University for our sample analyses. Imagine my excitement when I realized that my assignment was turning into a real pilot study that now included a collaboration with one of the experts whose articles I cited in my literature review. I was over the moon!
The NKU Biology faculty bolstered me again by providing me with lab equipment and supplies to clean my feathers, and proper packaging and funding to ship our samples to Dr. Brasso’s lab. My pilot study would never have taken place without the guidance and support of the faculty at NKU, and I will always remember their generosity and kindness. And of course, there was the time that Dr. Walters spent on the project and the additional permits she applied for in order for us to obtain our samples. I would be remiss if I did not also mention that my employer, Staples, allowed me to change my work schedule so that I could be in the field when I needed to be.
Our pilot went well, and together, Dr. Walters and I came up with a formal grant proposal in 2019. Our plan was to compare the concentration of mercury in the feathers and blood of 13-day-old nestlings taken during banding, to try to gauge what relationship existed between the two tissue types from the same nestling on the same day. We hypothesized that a there would be more mercury in the feathers than in the blood at this stage of rapid growth, when most of the mercury they consumed might quickly be offloaded into their growing feathers. If our hypothesis was supported, then simply collecting feathers during banding could tell us something about what level of mercury the nestling had assimilated into its tissues since hatching, without having to take blood samples. In March of 2020, we learned that we were the lucky recipients of a 2020 WOS Jed Burtt Undergraduate Mentoring Grant. We now had funding to buy our own lab reagents and feather sampling supplies!
Just as we started planning our research for 2020, the pandemic hit. This meant, of course, that our field and lab work had to come to a standstill for a while. I used this time to read through literature, write up our detailed protocol, and come up with some more questions we could ask with our data. In 2021, we were able to complete our fieldwork, sample processing, and analyses as originally outlined in our proposal. We found that our data supported our hypothesis, with feathers being the ideal way to sample mercury contamination because they had proportional, but much higher, levels of mercury than blood in banding-age nestlings. We are now working on publishing our results.
I am sharing my story today because, in a lot of ways, it feels quite serendipitous. I don’t think I ever could have planned for the way things all fell into place. They all just happened to be, and I am grateful that I was open to the new opportunities and relationships that came before me when they did. From answering that first ad in the paper, to setting us up with NestWatch, to deciding to go back to school… I never had a research project in mind as the end goal when doing these things, but they all were important parts of the story. The people I met along the way had everything to do with the outcome, too: The support from Steve and Rhonda at KCP&R, meeting Dr. Walters and working with her, Dr. Curran’s encouragement in my science writing class, our collaboration with Dr. Brasso, having an employer that allowed schedule flexibility for higher education, and the supplies and advice I received from faculty at NKU. I could never ask for a better, more supportive professional circle of people. Their support and kindness have meant everything to me, and to the success of this project.