The Effects of Railroad Noise on Bird Populations

Focus Area

Wildlife & Ecosystems


Natural Resources






2-3 years

Research Idea Scope

TERI Database Administrator Notes.  Not recommended at present time by 2009 Natural Systems Subcommittee.

Transportation noise has the potential to negatively impact animal populations.  In recent years several studies have attempted to quantify the effect of highway noise on bird populations with limited success, but there are essentially no data on the effect of railroad noise, which has very different characteristics from highway noise.  We propose to quantify railroad noise and examine its’ impact on bird populations.  Our proposed study areas are along the Elgin, Joliet and Eastern rail line (Lake, Cook, DuPage and Will Counties, IL) recently purchased by the Canadian National Railroad. Birds rely on hearing and vocal communication to a great degree and therefore are potentially highly sensitive to railroad noise.  This noise may negatively affect the health and viability of bird populations in a variety of ways (e.g. direct hearing damage, increased stress, and audio masking) and can influence both individual fitness and population viability. We will record train-generated sound in selected study areas and model how sound moves and attenuates through the environment.  We will record the ‘soundscape’ in a variety of habitats using protocols we have developed and tested.  These data will be analyzed using dynamic flow models and will characterize how train sound attenuates with respect to physical features (e.g. vegetation, and buildings) and atmospheric conditions (e.g. humidity, temperature).  Models will be predictive and will be a substantial advance over the general acoustic “boundaries” described in current impact studies. Our results will be generalizable to other railroad sites. Wireless microphone arrays (developed by INHS) will be used to record all vocalizing birds in selected areas.  Each array consists of 10 to 16 microphone transmitters spaced 30 m apart.  Sound is transmitted from each mic to computers via radio frequencies.  These data will allow us to characterize the community structure and vocalization behavior of birds in relation to train noise using tools developed by the National Center for Supercomputing Applications.  We also will attach small (1.5 g) microphone transmitters to male songbirds.  These transmitters will allow us to record individuals continuously, and further test the effects of train noise on birds’ vocal behavior and movement. We will assess the stress level of birds in response to passing trains using (1.5 g) heart-rate transmitters attached to incubating female birds near tracks.  Many studies have found that elevated heart rates are symptomatic of high stress levels.  Data from the transmitters can be collected and analyzed using the same tools used in audio analysis. We will also monitor the breeding bird communities in our study sites in relation to track proximity and the frequency and dB level of train noise. 

We will determine relative abundance of bird species using standard ‘point counts’ in the study areas.  Census points will be systematically distributed in relation to habitat and distance from tracks.  We will determine the fledging success of selected species and individuals in the study site as a function of habitat, proximity to tracks, and noise level.  We also will use motion-sensitive digital wildlife-viewing cameras to monitor the effect of passing trains on incubating birds.  These data will be used to test whether passing trains have a direct effect on nest predation.  If attending parents are flushed from nests by passing trains making the nests more vulnerable to predators (e.g., mammals, snakes). This study will be the most comprehensive to date on the effects of railroad noise on birds.

Urgency and Payoff

This study will be the most comprehensive to date on the effects of railroad noise on birds. This study will also provide a comprehensive quantification of noise propagation in relation to environmental features along a railroad.

Suggested By

Dr. David Enstrom, Illinois Natural History Survey, U of Illinois, Champ