Birds and rails: Do birds live on the wrong side of the tracks?
By Sam Baraoidan, Masters student, Wildlife Ecology & Conservation Department
When we are looking to buy a home, a primary concern is always whether or not our new house will be in a good neighborhood. But what about wildlife? Do rodents, lizards, or owls care about moving in on “the wrong side of the tracks?” Dr. Christopher Whelan was part of a large environmental impact study designed to answer that question – literally. Dr. Whelan and several other researchers from the Illinois Natural History Survey were asked to investigate the potential effects of increased railroad traffic on wildlife in the Chicago metropolitan area. The study was very broad, and researchers collected data on insects, mammals, amphibians, reptiles, plants, fish, and more. Since he specializes in birds, Dr. Whelan oversaw the avian-focused portion of the study.
While he is perhaps best known for his work on the foraging ecology of birds, Dr. Whelan and his students have a broad range of research interests, including nest predation, insect pest control by birds, and the effects of climate change on Arctic ground squirrels – just to name a few! With over 50 publications in peer-reviewed journals, 6 technical reports, 13 articles in the popular press, and 9 book chapters, the impacts of Dr. Whelan’s research are far-reaching. He is also the co-editor of two books, one set to be published in 2016. In addition to his position as an Avian Ecologist with the Illinois Natural History Survey, Dr. Whelan is also a Graduate Faculty Scholar at Northern Illinois University and a Visiting Research Associate Professor at the University of Illinois at Chicago.
For most people, Chicago conjures images of skyscrapers, Wrigley Field, and pizza.
Many of you might be wondering what kind of wildlife even exists in “Chicagoland” – a common nickname for the Chicago metropolitan area, which boasts a population of nearly 10 million people. You may be surprised to learn that there are actually many parks and protected areas scattered throughout the city. Because of the potential risks associated with increased railroad traffic in Chicago, the company that owns the railway wanted more information about how wildlife might be affected.
Determining how a railway might affect wildlife after the railway has already been built is a bit of a tricky task. Because of this, Dr. Whelan had to develop a creative study design. His research team monitored bird activity at varying distances from the railway and at different levels of train activity.
Specifically, they recorded four main types of information:
- Which bird species were present? Bird species were identified through both visual observations and recognition of their songs or calls. Listening for bird songs and calls also allowed the researchers to record how frequently birds were communicating with one another.
- How frequently were they observing each species? The researchers wanted to know if certain bird species were dominating the bird community, perhaps because they were able to adapt better to life along the tracks.
- When and where was each species nesting, and how successful were these nests? This was done by first locating bird nests, and then monitoring the nests closely as the eggs developed, all the way until the baby birds hatched and fledged from the nest (if that particular nest made it that far).
- How were birds foraging, and was their behavior different at varying distances from the train tracks? Foraging is simply the process of wildlife searching for and then consuming food resources.
They repeated these observations over the course of several years in order to get the best idea of how the railway might be affecting the birds.
Dr. Whelan and his team found that the railroad and associated train traffic had no measurable negative effects on birds in the surrounding areas. Some of their main findings were:
- A variety of common bird species that would be expected in that type of habitat were present throughout the study area.
- No birds were observed displaying any sort of alarm calls or alarm behavior near the tracks or as a reaction to passing trains.
- Distance from the railroad did not appear to affect how often birds sang or called. The team hypothesized that noise from passing trains might affect the success of this communication, but was unable to test this hypothesis.
- Nesting was less common as they got closer to the train tracks, but the breeding (and nesting success) was enough to sustain populations of the common species they observed.
- No birds were observed reacting negatively to the trains passing.
Overall, Dr. Whelan’s work on this project showcases a great example of how wildlife can exist successfully within an urbanized landscape. Even in one of North America’s largest cities, the inclusion of “green spaces” can provide crucial habitat for native wildlife – no matter which side of the tracks they are on!