Ecological Archives E091-172-A6

Peter N. Epanchin, Roland A. Knapp, and Sharon P. Lawler. 2010. Nonnative trout impact an alpine-nesting bird by altering aquatic insect subsidies. Ecology 91:2406–2415.

Appendix F. Analyses of the effect of mayfly density and their emergence on Gray-crowned Rosy-Finch abundance.

TABLE F1. Results of the best fitting multiple linear regression model (determined by AICc) testing the relationship between Gray-crowned Rosy-Finch abundance (average observed per 10 min count at a lake during the mayfly emergence period) and the number of mayfly nymphs sampled at the 24 lakes sampled in 2006 (adjusted R2 = 0.5004).

Source

Sum of Squares

df

F

P

Number of mayfly larvae

0.584

1

12.58

0.0046

Lake pair

1.787

11

3.5

0.0244

 

TABLE F2. AICc rankings of multiple linear regression models testing the relationship between Gray-crowned Rosy-Finch abundance (average per 10 min count during mayfly emergence) and the number of mayflies, lake pair, and all combinations of up to three of the six habitat parameters (i.e., covariates) at the 24 lakes sampled in 2006.

Covariate

k

AICc

∆AICc

w

no covariates

13

-29.99

0.00

0.958

elevation

14

-22.92

7.07

0.028

perimeter

14

-18.82

11.17

0.004

depth

14

-18.37

11.62

0.003

tree density

14

-18.27

11.72

0.003

surface area

14

-17.97

12.03

0.002

perimeter:surface area

14

-17.75

12.24

0.002

elevation, depth

15

-11.10

18.89

0.000

elevation, perimeter

15

-7.77

22.22

0.000

elevation, perimeter:surface area

15

-7.73

22.26

0.000

tree density, elevation

15

-7.59

22.40

0.000

elevation, surface area

15

-7.59

22.41

0.000

perimeter, depth

15

-6.81

23.19

0.000

surface area, perimeter:surface area

15

-5.99

24.00

0.000

perimeter, perimeter:surface area

15

-5.90

24.09

0.000

tree density, perimeter

15

-5.88

24.11

0.000

surface area, perimeter

15

-5.34

24.66

0.000

surface area, depth

15

-4.46

25.53

0.000

tree density, surface area

15

-4.22

25.78

0.000

tree density, depth

15

-3.26

26.73

0.000

perimeter:surface area, depth

15

-3.11

26.88

0.000

tree density, perimeter:surface area

15

-3.05

26.94

0.000

elevation, perimeter, depth

16

5.24

35.23

0.000

elevation, surface area, depth

16

6.77

36.76

0.000

tree density, elevation, depth

16

7.11

37.10

0.000

elevation, perimeter:surface area, depth

16

8.22

38.21

0.000

surface area, perimeter:surface area, depth

16

10.36

40.35

0.000

elevation, surface area, perimeter:surface area

16

10.42

40.41

0.000

elevation, perimeter, perimeter:surface area

16

10.55

40.54

0.000

perimeter, perimeter:surface area, depth

16

10.65

40.64

0.000

tree density, perimeter, depth

16

10.89

40.88

0.000

elevation, surface area, perimeter

16

10.93

40.92

0.000

surface area, perimeter, depth

16

11.37

41.36

0.000

tree density, elevation, perimeter

16

11.71

41.70

0.000

tree density, elevation, perimeter:surface area

16

11.92

41.91

0.000

tree density, elevation, surface area

16

12.11

42.10

0.000

tree density, perimeter, perimeter:surface area

16

12.55

42.54

0.000

tree density, surface area, perimeter:surface area

16

12.66

42.66

0.000

tree density, surface area, perimeter

16

12.84

42.83

0.000

surface area, perimeter, perimeter:surface area

16

13.66

43.65

0.000

tree density, surface area, depth

16

13.85

43.84

0.000

tree density, perimeter:surface area, depth

16

16.11

46.11

0.000

Note: Models ranked in order of minimum AICc value; w = Akaike weight

 

 

TABLE F3. AICc rankings of general linear mixed effects models used to analyze repeated measures data (n = 92) from all years of the study across 26 lakes. Gray-crowned Rosy-Finch abundance (average per 10 min count) predicted as a function of mayfly emergence period, fish presence, year, their interactions, and all combinations of up to three of the six habitat parameters (i.e., covariates).

Covariate

k

AICc

Δ AICc

w

tree density, perimeter:surface area

20

403.59

0.00

0.899

tree density

19

409.16

5.56

0.056

tree density, perimeter:surface area, depth

21

411.00

7.41

0.022

perimeter:surface area

19

412.26

8.66

0.012

tree density, elevation, perimeter:surface area

21

413.40

9.81

0.007

tree density, depth

20

416.53

12.94

0.001

tree density, perimeter, perimeter:surface area

21

416.90

13.31

0.001

no covariates

18

417.97

14.38

0.001

tree density, elevation

20

418.53

14.94

0.001

perimeter:surface area, depth

20

419.43

15.84

0.000

elevation, perimeter:surface area

20

419.53

15.94

0.000

tree density, perimeter

20

424.73

21.14

0.000

elevation

19

424.76

21.16

0.000

depth

19

425.06

21.46

0.000

perimeter, perimeter:surface area

20

425.63

22.04

0.000

tree density, elevation, depth

21

425.90

22.31

0.000

tree density, surface area, perimeter:surface area

21

426.70

23.11

0.000

elevation, perimeter:surface area, depth

21

426.70

23.11

0.000

elevation, depth

20

431.83

28.24

0.000

tree density, perimeter, depth

21

432.10

28.51

0.000

perimeter, perimeter:surface area, depth

21

432.90

29.31

0.000

tree density, surface area

20

433.33

29.74

0.000

perimeter

19

433.36

29.76

0.000

elevation, perimeter, perimeter:surface area

21

434.20

30.61

0.000

tree density, elevation, perimeter

21

434.40

30.81

0.000

surface area, perimeter:surface area

20

435.33

31.74

0.000

elevation, perimeter

20

440.53

36.94

0.000

perimeter, depth

20

440.53

36.94

0.000

tree density, surface area, depth

21

440.80

37.21

0.000

surface area

19

441.96

38.36

0.000

elevation, surface area, perimeter:surface area

21

442.10

38.51

0.000

tree density, elevation, surface area

21

442.60

39.01

0.000

surface area, perimeter:surface area, depth

21

442.60

39.01

0.000

tree density, surface area, perimeter

21

445.60

42.01

0.000

surface area, perimeter, perimeter:surface area

21

447.10

43.51

0.000

elevation, perimeter, depth

21

447.70

44.11

0.000

elevation, surface area

20

448.53

44.94

0.000

surface area, depth

20

449.23

45.64

0.000

surface area, perimeter

20

454.03

50.44

0.000

elevation, surface area, depth

21

455.80

52.21

0.000

surface area, perimeter, depth

21

461.40

57.81

0.000

elevation, surface area, perimeter

21

461.50

57.91

0.000

Note: Models ranked in order of minimum AICc value; w = Akaike weight

 

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