For this activity, I’d like you to investigate the following question: Have the winter birds species in your area changed over the past 20 years?
How might you answer this question? There are several organizations that have collected data on winter birds and these data sets are available on the Internet. These data have been collected, largely, by members of the general public and are a great example of the results of citizen science projects.
- Start by going to Project Feederwatch at the Cornell Laboratory of Ornithology. Go to “Explore Data” and then select “Bird Summaries by State or Province.”
- Start with the earliest year for which data is available (1988-89) and calculate the average percent of sites visited during the season, starting with the most abundant species. Calculate the average for the second most abundant species. Then the third. Repeat this through the fifth most abundant species.
- Take those five species that were most abundant in 1988-89 and calculate the average percent of sites visited for the year 1990-91.
- Repeat the calculations at two year intervals, up to the most recent data set.
- Plot graphs of year (x-axis) against average percent of sites visited (y-axis) for each of the five species. Do you see any clear trends towards increasing or decreasing frequency of occurrence?
- Write a report (400-500 words) in which you discuss your results, present your five graphs, and answer the following questions: (use the internet or resources listed in the ‘Further Information..’ page)
- Which species appear to have become less common?
- Can you think of any explanations for the changes?
- Which species appear to have become more common over time?