1. Effects of Acid Mine Drainage (AMD) on Nesting Tree Swallows

2. Acid Mine Drainage (AMD) Streams contaminated with AMD cause ecological and biological stresses by Low pH High metal concentrations Deposition of metal oxides

3. Ecological Effects of AMD Effects at all levels of food chain from periphyton and fungal communities upwards Effects on invertebrates include –Reduced abundance and biomass –Reduced species diversity –Shift in species composition from metal- intolerant taxa to metal-tolerant taxa (mayflies shown to be more susceptible)

4. Effects of AMD (cont’d) Tree Swallows Readily use nestboxes Feed near their nestboxes (< 400m) Primarily eat emergent aquatic insects

5. Study Objectives Evaluate the relationships among metal concentrations detected in the water, benthic invertebrates and nesting tree swallows Evaluate the effect of streams contaminated with heavy metals on the nesting success of tree swallows

6. Study Area Central Colorado near Keystone Ski Resort 9 sites selected along Snake River and two tributaries (St John’s Creek and Deer Creek) 10-30 nestboxes erected at sites May 2003

7. Upper Snake River Low pH High metal concentrations Deer Creek Near neutral pH Low metal concentrations St John’s Creek Near neutral pH Low metal concentrations

8. Methods Samples collected at each site included: Water samples Benthic invertebrates Aerial invertebrates Tree swallow livers and diets

9. Methods - Water Samples Collected in triplicates in 250ml Nalgene bottles on weekly basis during summer 2004 Sampling dates are 6/17, 6/21, 6/28, 7/8, 7/15, 7/22, and 7/29 Chemical analysis by USGS, Denver - metal concentrations - pH and conductivity

10. Methods – Benthic Invertebrates Surber and Ekman grabs used Samples collected on 6/24, 7/1, 7/8, 7/15, 7/22 and 8/1 during 2004 Number of samples varied from site to site Metal concentration analysis by USGS, Denver

11. Methods – Aerial Invertebrates Assess food availability at each site Used aerial tow-nets that rotate in the wind

13. Methods – Tree Swallow Monitoring/Sampling Part of a larger study conducted by Christine Custer (USGS, La Crosse, WI) to analyze effects of trace metals on tree swallows Nestboxes monitored on weekly basis from 1 st week of June to last week in July (2003 and 2004) Progress of nest construction, number of eggs/young recorded Nestling liver and diet samples collected Metal analysis done by USGS, Denver

14. Tree Swallow Nests

15. Statistical Analysis Regressions between metal concentrations detected in the water, benthic invertebrates, nestling diets and livers Principal Component Analysis (PCA) was also used to analyze metal concentrations in the water, benthic invertebrates, nestling diets and livers

16. Water Quality Results pH lowest at MS Conductivity highest at MS MS had the highest Al, Zn, Pb and Cd concentrations for most days US water chemistry more similar to those along Deer Creek than MS

17. Water Results - pH

18. Water Results – Conductivity

19. Al Concentrations

20. Zn Concentrations

21. Benthic Invertebrates Results Highest number of taxa caught along Deer Creek sites

22. Number of taxa of invertebrates caught at each site by sampling day. No insects were caught at MS on 7/1/04. 24-Jun1-Jul8-Jul15-Jul22-Jul1-Aug # of taxa # of sam. # of taxa # of sam. # of taxa # of sam. # of taxa # of sam. # of taxa # of sam. # of taxa # of sam. Upper Deer 423342824262 Middle Deer 6172111715182 Lower Deer 317291915152 St John 416462637385 Upper Snake 262555143525 Middle Snake 35NA 25352526 Montezuma 2223231535412 Denver Water 1237274638511 Keystone 256728273748

23. Number of individual invertebrates caught at each site by sampling day. 24-Jun1-Jul8-Jul15-Jul22-Jul1-Aug # of ind. # of sam. # of ind. # of sam. # of ind. # of sam. # of ind. # of sam. # of ind. # of sam. # of ind. # of sam. Upper Deer 52133232272562232 Middle Deer 81172411441371492 Lower Deer 131412391461561262 St John 91154232263383535 Upper Snake 23625355774875945 Middle Snake 35NA 495795805676 Montezuma 202113253 52051412 Denver Water 12372073161882511 Keystone 2516738117307278

24. Metal Concentrations in Benthic Invertebrates For benthic invertebrates, most of the highest metal concentrations were detected at MD and MS Highest average Al, Co, Mn, Ni, and Pb, concentrations at MD Highest average Cd, Cr, Zn concentrations at MS Highest average Fe concentration at US Huge contrast to water samples.

25. Fe Concentrations in Invertebrates

26. Al, Mn, Zn concentrations

27. Cu and Pb Concentrations

28. Cd, Co, Cr and Ni concentrations

29. Aerial Invertebrate Results Based on number of individuals caught, no significant difference among the sites Over 60% of invertebrates belonged to the Order Diptera Most invertebrates between 3-8mm; few Lepidoptera and Trichoptera Invertebrates with larger biomass such as Odonota, Plecoptera and Ephemeroptera were not caught at any sites Does not seem to be any difference in food availability for the tree swallows

30. Nest Occupancy Rates # of nests available 20032004 Total Occupied TSTS MCMC VGVG MBMB Percent Occupied Total Occupied TSTS MCMC VGVG MBMB Percent Occupied Upper Deer 1011000 3101130 Middle Deer 7000000000000 Lower Deer 90000003120033 St John 131100084130031 Upper Snake 25000000220008 Middle Snake 1000000010100 Montezuma 1843100228341044 Denver Water 1422000 110007 Keystone 20770003510730050 Overall 126 1510 3021

31. Interaction between Water Quality, Benthic Invertebrates, and Tree Swallows PCA of metal concentrations in water quality, invertebrates, and tree swallow livers Correlation between metal concentrations in water quality, invertebrates, tree swallow diets and nestlings

32. Correlation Between Metals in Water and Bird Samples Water and LiverWater and Diet r 2 valuesP-valuesr 2 valuesP-values Cd0.460.070.050.60 Co0.060.550.010.87 Cu0.190.280.040.63 Fe0.810.00220.000.92 Mn0.470.060.130.14 Pb0.190.290.070.52 Zn0.280.170.200.26

33. Correlation in Metals Between Water and Benthic Invertebrate Samples r 2 valuesP-values Al0.040.61 Cd0.100.40 Co0.000.87 Fe0.300.13 Mn0.090.43 Pb0.090.45 Zn0.170.26

34. Correlation Between Metals in Nestling Diets, Livers and Invertebrates Diet and Liver (n=17) Diet and Invertebrates (n=8) r2r2 p-valuesr2P-values AlNA 0.000.98 Cd0.001.000.080.49 Co0.620.020.070.53 Cr0.380.110.120.40 Cu0.640.020.050.61 Fe0.100.450.040.64 Mn0.23 0.000.98 Pb0.350.120.020.71 Zn0.200.260.250.20

35. Correlation in Metals Between Benthic Invertebrate and Liver Samples r2r2 P-values Cd0.770.004 Co0.040.64 Cr0.700.010 Cu0.090.48 Fe0.120.41 Pb0.460.07 Zn0.760.005

36. Principal Component Analysis (PCA) Principal Component Analysis was used to analyze metal concentrations in the water, macroinvertebrate samples, nestling diets and livers. PCA reduces the dimensionality of a large set of data by transforming a number of correlated variables into a smaller number of uncorrelated variables (principal components) Takes metal concentrations (correlated variables) in samples and transforms them into principal components

37. PCA – Metal Concentrations in Water Samples PC1PC2 Al0.3565-0.15 Cd0.3503-0.0836 Co0.3712-0.1742 Cu0.3729-0.1645 Fe0.3247-0.0774 Mn0.36010.0931 Ni0.3717-0.1849 Pb0.1620.7578 Zn0.27180.5386

38. PCA – Metal Concentrations in Benthic Invertebrates PC1PC2 Al-0.33550.3471 Cr-0.3055-0.3009 Mn-0.33430.0574 Fe-0.1281-0.4951 Co-0.34870.2092 Ni-0.3881-0.0195 Cu-0.06950.6491 Zn-0.3463-0.1579 Cd-0.3605-0.2014 Pb-0.37270.0979

39. PCA – Metal Concentrations in Nestling Diets PC1PC2 Al-0.1539-0.6128 Cr-0.32710.1865 Mn-0.3685-0.2803 Fe-0.3504-0.2803 Co-0.3462-0.1807 Ni-0.2741-0.2577 Cu-0.26970.5051 Zn-0.38380.1091 Cd-0.33450.3353 Pb-0.2896-0.1691

40. PCA – Invertebrate Composition Subscripts 1,2,3,4,5, and 6 denotes sampling days 6/24, 7/1, 7/8, 7/15, 7/22 and 8/1 respectively

41. Discussion – Water Samples Water samples are important for understanding overall water quality Poor indicator of nest occupancy rates Poor correlation between metals in water and in benthic invertebrates Significant correlation between Fe concentrations in water and nestling diet Poor correlation between all metal concentrations in water and nestling livers

42. Discussion – Metal Concentrations in Benthic Invertebrates Metal concentrations in benthic invertebrates are good predictors of nest occupancy rates for a site Significant correlation between Cd, Cr and Zn concentrations between benthic invertebrates and nestling livers

43. Discussion Correlation may be affected by averaging metal concentrations in nestling livers, diets and invertebrates Unclear why metal concentrations in benthic invertebrates at MD is so high; sediment and *aufwuchs samples should be included in future studies *aufwuchs - biotic and abiotic material accumulating on submerged surfaces

44. Conclusion AMD does have an effect on nesting tree swallows: tree swallows seem to be avoiding sites where metal concentrations in benthic invertebrates are high high correlation between Cd, Cr and Zn concentrations between benthic invertebrates and nestling livers