Fordham University, Project TRUE… · 2016. 12. 6. · Wetland Quality and Abundance of Invasive Bird Species Grace Sperling, Henry A. Takizawa, Abdel Rahman Mohamed Fordham University,
1
Wetland Quality and Abundance of Invasive Bird Species Grace Sperling, Henry A. Takizawa, Abdel Rahman Mohamed Fordham University, Project TRUE Introduction Research Question Methods Does water quality correlate with the abundance of invasive and/or na7ve bird species in a wetland? References Hypotheses We hypothesized that the be<er the quality of the wetland, the higher the abundance of na7ve bird species. Addi7onally, we hypothesized that the poorer the quality of the wetland, the higher the abundance of invasive bird species. A wetland is a habitat that houses numerous species (1). The merging of aqua7c and terrestrial characteris7cs is what contributes to wetland biodiversity. However, an increased rate of urbaniza7on has made it easier for nonGna7ve bird species to infiltrate wetlands (2). These introduced species of bird go on to compete with the na7ve bird species for limited resources in the habitat. As indicator species, birds are used to predict the quality of wetlands. Invasive bird species tend to adapt to unhealthy condi7ons be<er than na7ve bird species are able to (1). This brings into ques7on how wetland quality relates to invasive bird species. Point Counts and Sta-ons: Four point count sta7ons were selected, each covering an area with a 50 meter radius at the edge of each of our wetland sites (The Rambles, Meadow Lake, Willow Lake and Spuyten Duyvil Creek). Two bird counts were conducted at each sta7on, one in the morning and one in the aTernoon. Two more count sta7ons were randomly selected along each wetland’s perimeter, summing up our bird counts to a total of ten. Bird Observa-on and ID: Our setup for bird iden7fica7on followed the dependent observer model. This consisted of a primary observer whose sole job is to iden7fy birds from both visual and auditory incidence and a secondary observer whose job is to record bird observa7on while assis7ng the primary observer with any missed sigh7ngs. 1. McKinney, Richard A., Kenneth B. Raposa, and Rose M. Cournoyer. "Wetlands as habitat in urbanizing landscapes: pa<erns of bird abundance and occupancy." Landscape and Urban Planning 100.1 (2011): 144G152. 2. McKinney, Michael L. "Urbaniza7on, Biodiversity, and Conserva7on. BioScience 52.10 (2002) 883G890. 3. Air Quality Index Basics. EPA. 2015, March 16. Retrieved August 5, 2015 from h<p://airnow.gov/index.cfm?ac7on=aqibasics.aqi 4. Nitrogen and Water. USGS. Retrieved August 10, 2015, from h<p://water.usgs.gov/edu/nitrogen.html Results Photo 1. Project Leader Lily and Field Research Leader Abdel conduct a dependent observa7on. Water Quality Tes-ng : Our four wetland sites were examined for their water quality by tes7ng several abio7c parameters (DO, free CO2, salinity, pH, hardness, nitrates and phosphates). The four water samples that were collected from each wetland came from the same four point loca7ons where we conducted our bird observa7ons. Photo 2. Field Research Assistants Henry and Grace test a water sample for nitrate and phosphate concentra7ons using the LaMo<e® Limnology kit. Figure 1. Depicts the abundance of birds by species at each of our four wetland sites. Invasive species are shown in red while na7ve are blue. Figure 3. Shows the correla7on between the percentage of invasive bird abundance and several water quality parameters that we tested for at each of our four wetland sites. Note: We collected water salinity and hardness data but chose to exclude their correla7on to invasive bird abundance because some of our wetland sites were freshwater bodies while others were brackish/saltwater bodies. Discussion and Conclusions Our results show that Willow Lake has the highest overall bird richness and the lowest abundance of invasive birds. The Rambles had the lowest bird richness but Spuyten Duyvil Creek had the highest percentage of invasive birds. The data shows a posi7ve trend between water acidity and invasive bird abundance. Invasive bird species tolerate lower pH levels, so when water pH increased, it was the na7ve birds that thrived (2). As phosphate and nitrate content increased, invasive bird abundance decreased. The presence of nitrates and phosphates is crucial for photosynthesizing algae and plants. Nitrate and phosphate readings at all of sites never reached levels that can cause eutrophica7on (4). We found the higher the water temperature, the greater the abundance of invasive birds. During our morning bird counts, we observed more na7ve than invasive birds. Later in the aTernoon, when the temperature increased, the number of na7ve bird decreased and that of the more heatGtolerant invasives increased (2). Using the EPA’s Air Quality Index, we determined that the air quality of our wetlands was considered sa7sfactory, posing li<le to no risks to the wetlands (3). The greater the amount of grey infrastructure, the higher amount of invasive bird richness. Results support our hypotheses by showing that when water parameters were at favorable levels, the abundance of na7ve bird species increased and that of invasive species decreased. The na7ve species inability to tolerate unfavorable habitat condi7ons and the invasive species’ adaptability to these condi7ons may have a<ributed to our findings. Figure 5. Area of grey and green infrastructure at our four wetland sites Independent Teen Studies Ques-on: How does air quality in and surrounding the wetlands affect the health of the wetlands? Methods: Using the Airbeam®, we collected air quality readings (par7culate ma<er 2.5, humidity, noise level and temperature) by walking along the edge of each of our wetlands. Ques-on: How is the species richness of invasive birds affected by the extent of urbaniza7on? Methods: Using Google Earth and ImageJ® we calculated the area of grey infrastructure versus that of green infrastructure and compared the results to our bird data. Grace’s Infrastructure Study Henry’s Air Quality Study Results from Independent Teen Studies Air Quality Data: Grey and Green Infrastructure Data: Figure 4. Average and peak levels of air quality parameters Figure 6. Correla7on between invasive bird richness and area of grey infrastructure at our wetland sites. Note: We also observed one of four addi7onal na-ve bird species. Note: We also observed one of nine addi7onal na-ve bird species. Note: We also observed one of four addi7onal na-ve bird species. Note: We also observed one of four addi7onal na-ve bird species. R: Correla7on Coefficient between G1 and 1. The further the number is from 0 the stronger the correla7on. Acknowledgements We would like to thank the WCS, Fordham University and everyone at project TRUE, especially project leaders Lily Mleczko and Amanda Makkay for their constant guidance, support and advice throughout this en7re project. We would also like to thank Jason Aloisio for his constant support and organiza7on efforts.
