Greg+Porter


 * Bird Behavior in the City**


 * Background Information**

"Urban habitats favor species that are less affected by toxic substances flowing through cities, that are better able to adapt to artificial light, to communicate over the noise of traffic and automation, to breed successfully on human built structures, and to rebound after city council decisions to decimate their populations. As more of the natural habitat of Earth is destroyed, urban birds will become more "typical" of our avifauna. As tongue-in-cheek evolutionists claim, birds may, indeed, be feathered dinosaurs. Many species of birds may soon follow the dinosaurs into extinction, but it seems likely that urban birds will be around as long as there are people to build cities."

"Urban Birds" 1988 by Paul R. Ehrlich, David S. Dobkin, and Darryl Wheye. http://www.stanford.edu/group/stanfordbirds/text/essays/Urban_Birds.html


 * Introduction**

In looking at birds in an urban environment, I am curious about how bird behavior is effected by the different "city noises" around them. In my study, I will‍ observe ‍ bird behavior in an urban setting and the effect (or lack of an effect) "city noises" as well as typical human interaction have on bird behavior.


 * Question**

How and when will behaviors of birds in an urban environment be effected by the "urban sounds" as well as typical human behavior that takes place in the city?


 * Hypothesis**

I think that the only effect on bird behavior will be physical proximity of a human or object to the birds themselves, with the sounds having little to no effect on bird behavior.


 * Materials**


 * data collection chart
 * laptop computer with pre-loaded "city noises" (ambulance siren, car honking)
 * my dog (Kima)
 * cell phone
 * small bean bags or marking devices(8-10)
 * measuring tape


 * Method**

1. Locate area on Bunker Hill Monument in Charlestown, MA where there is consistent bird activity. 2. Identify and record bird species and observable behavior in data collection chart. 3. Begin at a measured distance from the birds of 50 ft. Choose one specific bird to be your "target." 4. Walk slowly toward your target, making note of any behavior change. Mark spot with bean bag if behavior change noticed. Do so slowly, so as not to cause a further behavior change due to the beanbag movement. If noted, restart trial. 5. Continue toward target slowly until substantial movement noted (fly away, hop away, etc.). That is the final mark for the control group (no additional sounds, just person walking toward bird). 6. Record trial findings in chart. 7. Repeat steps 3-6, each time adding a different variable using the cell phone (call and talk to a friend during observation), dog, and computer (siren, honking).


 * Results**







There are several important claims I can make on the affect of city sounds on bird behavior based on the data I've collected over the last week. The scatter plot clearly shows that there is a general affect of city sounds on bird behavior. As soon as a variable of any kind is introduced, there is a change in behavior. The birds do not ignore this new variable, they respond to it. What was observed during my study is that when a variable was introduced, the bird stopped it's behavior, namely feeding on the side of a hill. It would then resume the initial behavior, only to be effected again.
 * Analysis**

More specifically, the first line graph outlines the break down between the two species I studied and their first and final behavior changes, the American Robin and the House Sparrow. The "first" change would be the moment at which the bird first reacted to the variable. The "final" change reflects the moment when the behavior is no longer taking place, in this case the bird hopping away from the initial mark or flying away altogether. It is clear that the House Sparrow reacted to the variables first, in terms of distance away of variable to bird, and that the sparrow was the first to make it's final change.

Finally, the side-by-side graphs are a comparative look at the variables introduced and their affect on the bird behavior. There are two several key points to make from this information. First, the "first" behavior changes occur in a large range of distances, from nearly 45 feet away to as close as almost 15 feet. Most of the variables overlap and show that they occur at approximately 25-35 feet. However, it is clear that the "dog" variable had the greatest affect on initial behavior change, as it is responsible for all of the "high" marks and it's results have distance gaps, oftentimes substantial, between itself and the other variables. It is also clear that the person walking, with no other variable introduced, was able to walk closer to the bird before inducing a behavior change.

When looking at the "final" behavior changes, there are clear trends, beginning again with the dog variable as the highest inducer of behavior change. The remaining variables all fell within the 15-30 foot range, with the person walking, with no additional variable, was able to walk closest to the bird before causing the final change in behavior.

My hypothesis, that I thought t the only affect on bird behavior would be physical proximity to the birds themselves, with the sounds having little to no affect on behavior, was incorrect. It is quite clear that the introduction of a variable, any variable, had an affect on the birds' behavior, regardless of species. The House Sparrow was clearly more effected by the variables than the American Robin, as evidenced by the data collected.
 * Conclusion**

There are several key conclusions that I can draw from my research, first of which comes from the data collected from my dependent variable, person walking. In data collected from first and final behavior change, I was able to get closest to the bird during this condition. It is clear that these urban birds have become accustomed to the presence of humans in their environment, and therefore do not see them as a serious threat to their safety or food source. Additionally, was is clear is that the only other live variable introduced, the dog, had the greatest affect on the behavior of the bird. This could be instinctual or learned, but it is clear that both species of bird regarded Kima as a threat. The other three variables (siren, horn, talking person) all had a similar range of distances and affect on the bird behavior, perhaps because these are such common occurrences in an urban environment.

There are two other additional key points to note regarding the different variables used in the experiment. The artificial sounds generated were not done performed in as realistic a way as I would have liked. The use of my laptop computer limited the volume with which I could play the siren and horn honking sounds, so those do not accurately reflect how it would sound in day to day life. Also, while I attempted to walk with the same pace during each trial, it is important to note that I did not use a tool of any kind to regulate said pace. And finally, the dog was leashed during this activity, for obvious reasons, but these trials do not reflect how this event (dog walking/stalking a bird) would take place without human influence. Perhaps the dog and person in tandem were viewed as a threat, versus a dog by itself.


 * Discussion**

There were several problems I encountered during the data collection, first of which was natural occurrence of city sounds. I was thus forced to generate the sounds on my computer, but without adequate volume. Perhaps a mobile device and/or speakers could help me to more accurately reflect the siren and horn occurring in real time. Also, it was difficult to set the parameters for measuring distance, as the birds are almost constantly moving. All the data collected reflects an approximation based on the location of the bean bags used to mark the starting and ending locations of the birds and variables. Pre-marking popular feeding spots may have alleviated this problem, or I could have created a feeding location that I had pre-measured for distance by putting out bird feed. In recreating this investigation, I would also collect baseline data regarding typical movement of the birds and how long they feed before relocating, so that I could compare the baseline data and that which I collect.

My conclusion have led me to new questions regarding my overall topic. First, I am curious about the dispositions of the two species of bird studied, the sparrow and the robin. Is this typical reactionary behavior for these species? What are their natural feeding habits and what affect might that have had on the results? Did the location of the study have anything to do with the results, as the park was surrounded on all four sides by a fence-did that give them a sense of protection and safety from outside threats? And finally, what are seen as "natural" threats for robins and sparrows? Could I have created "city sounds" that are closely linked in sound to these natural threats and would that have given me different results?