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Man vs. Bird: Effects of Human Activity on Bird Richness and Abundance Kathryn Oteri, Barbara Anane, Mia K. Calderon, Kayla Pluviose, Joseph Svoboda and Danielle Lema
RESEARCH QUESTIONS
RESULTS
DISCUSSION
• Is there a correlation between human activity and bird richness? We hypothesized that bird richness will decrease with increasing human activity. • Does population density of surrounding area affect bird abundance? We hypothesized that bird abundance will decrease with increasing population density. • Does the amount of particulate matter affect bird richness? We hypothesized that bird richness will decrease with increasing amounts of particulate matter. • Does the presence of water affect bird richness? We hypothesized that bird richness will increase with increasing presence of water.
INTRODUCTION A primary goal of urban ecology is to study how the development of cities affects the natural environment around us. Urbanization is one of the most devastating forms of habitat loss for wildlife, and birds are no exception;; their ability to survive and reproduce is threatened with increasing urbanization (Barber et. al 2010). Urbanization stimulates greater human population density, consequently increasing the level of human activity, a factor that can be classified as one of many stressors on local birds (Schlesinger et. al 2008). Additionally, increasing urbanization is partially responsible for heightened levels of particulate matter due to air pollution and loss or fragmentation of natural resources such as bodies of water;; both of which further inhibit birds from thriving in an environment (Pitelka 1994, McKinney 2002). In this study we observe the correlation between human activity and species richness. Surveying areas of different levels of urbanization with varying amounts of human activity could be helpful in determining which species of birds are in the most danger of population decline as a result of urbanization.
● There is a slight inverse relationship between the number of vehicles/people and average bird richness, so the data supports our hypothesis (Figure 1). The Bronx Zoo is considered an urban green space because, although it is located in the city, it contains many acres of trees and suitable habitats for animals. The sites with low and medium levels of human activity both still had relatively high average richness. However, B3, the site with the highest activity in the Bronx Zoo, had a much lower average richness. This demonstrates human activity impacts green spaces.
Figure 1 displays the relationship between average bird richness and the average number of people and vehicles at each site.
Figure 2 displays the relationship between relative abundance and surrounding population density for the 3 site locations.
● Figure 3 supports our hypothesis by showing that as particulate matter increases, average bird richness decreases. However, two sites from the Bronx Zoo had high amounts of particulate matter and high bird richness. A possible explanation for this could be the nearby parking lots causing higher amounts of particulate matter. The only Bronx Zoo site not close to a parking lot did follow the trendline.
Figure 3 displays the relationship between average bird richness and particulate matter.
Figure 4 displays the relationship between average bird richness and the amount of water present.
● At both the Bronx Zoo and Starlight Park, it is clear that bird richness increases with increasing water abundance (Figure 4). Data from the Calder Center, however, did not have a constant increase in relation to richness and water abundance. This might be because the Calder Center offers greater habitat availability for birds in comparison to the limited spaces and water sources of Bronx Zoo and Starlight Park. ● We observed a total of 26 species of birds and 430 individual birds in sites with varying conditions. We can conclude that human activity has an overall negative impact on bird richness. Average richness is relatively low at sites that are more affected by human activity because the birds that are most often found at theses sites are “urban birds”;; birds such as American Robins, Gray Catbirds, House Sparrows, etc., that are better adapted to live in conditions that most birds find unfavorable.
METHODS Point counts were conducted at 3 locations within 3 different sites: the Louis Calder Center, the Bronx Zoo, and Starlight Park. Point counts began five minutes after arrival, and lasted for ten minutes. By recognizing field marks and listening for calls, observers recorded each bird seen or heard within a radius of 50 meters. Point counts were conducted both in the morning and afternoon at each site;; four point counts at each location were recorded over the course of two weeks. Human activity was surveyed at each site by counting the number of vehicles and humans seen at the closest roadway to the center of the point count during five minute intervals. Time of day, temperature, and weather were also recorded daily, and canopy coverage was measured at each site as a covariant. Amount of water present at each site and population density were both measured using Google Earth. Additionally, an AirBeam was used to determine the amount of particulate matter present at each site.
● As population density in surrounding areas increases, relative abundance increases (Figure 2). This trend does not support our initial hypothesis. The unexpected results may be due to the high volume of urban birds we saw in Bronx Zoo and Starlight;; an area with more people presents more food/nesting opportunities for birds that are well-adapted to urban areas, such as the House Sparrow.
ACKNOWLEDGEMENTS Colaptes auratus (Northern Flicker)
Cyanocitta cristata (Blue Jay)
Cardinalis cardinalis (Nothern Cardinal)
We would like to thank Fordham University, The Wildlife Conservation Society, and the Bronx Zoo for allowing us to use their spaces as we collected data. Thanks to program coordinators Jason Alosio and Kelsey Brennan, as well as Fordham and WCS staff members Dr. Alan Clark, Dr. James D. Lewis, Dr. Jason Munshi-South for their ongoing support. Thank you to the camera trap team for donating bird pictures, and all other undergraduate, graduate, and research experts for aiding us in our research.
REFERENCES
©Patuxent Wildlife Research Center
Corvus brachyrhynchos (American Crows)
Barber, J. R., K. R. Crooks, and K. M. Fristrup. 2010. The costs of chronic noise exposure for terrestrial organisms. Trends in Ecology & Evolution 25:180–189. McKinney, M. 2002. Urbanization, Biodiversity, and Conservation. BioScience 52(10):883-890. Pitelka, L. F. 1994. Air pollution and terrestrial ecosystems. - Ecol. Appl. 4 627-628. Schlesinger, M., Manley, P., and Holyoak, M. 2008. Distinguishing Stressors Acting on Land Bird Communities in an Urbanizing Environment. Ecology 89:2302-2314.