Appendix A. Results of the analyses for individual species.
TABLE A1. Stop-level analysis comparing the number and proportion of sites within Brood X where birds declined between year –1 and year 0 divided between stops where cicadas were heard vs. those where they were not.
Cicadas heard$ | No cicadas heard$ | ||||||
Species |
N surveys declining |
Total surveys conducted |
% surveys declining |
N surveys declining |
Total surveys conducted |
% surveys declining |
P # |
Red-headed Woodpecker | 4 | 4 | 100.0 | 3 | 4 | 75.0 | 1.00 |
Red-bellied Woodpecker | 19 | 31 | 61.3 | 14 | 31 | 45.2 | 0.31 |
Blue Jay | 19 | 33 | 57.6 | 22 | 33 | 66.7 | 0.61 |
American Crow | 34 | 45 | 75.6 | 34 | 45 | 75.6 | 1.00 |
Tufted Titmouse | 29 | 47 | 61.7 | 28 | 47 | 59.6 | 1.00 |
White-breasted Nuthatch | 7 | 11 | 63.6 | 6 | 11 | 54.5 | 1.00 |
Brown-headed Cowbird | 12 | 25 | 48.0 | 12 | 25 | 48.0 | 1.00 |
Common Grackle | 17 | 35 | 48.6 | 20 | 35 | 57.1 | 0.63 |
Northern Cardinal | 24 | 49 | 49.0 | 24 | 49 | 49.0 | 1.00 |
House Sparrow | 14 | 22 | 63.6 | 11 | 221 | 50.0 | 0.54 |
Brown Thrasher | 7 | 12 | 58.3 | 5 | 12 | 41.7 | 0.68 |
$ Includes only surveys where at least one individual was counted in year –1 at both stops where cicadas were heard and those where they were not; no such sites were available for American Kestrels. # Comparisons by Fisher exact tests. |
TABLE A2. Route-level analysis comparing the number and proportion of surveys where birds declined between year –1 and year 0 in surveys within the range of Brood X where cicadas were and were not heard calling.
Calling cicadas heard$ | No calling cicadas heard$ | ||||||
Species |
N surveys declining |
Total surveys conducted |
% surveys declining |
N surveys declining |
Total surveys conducted |
% surveys declining |
P # |
American Kestrel | 17 | 24 | 70.8 | 6 | 18 | 33.3 | 0.03 |
Red-headed Woodpecker | 7 | 12 | 58.3 | 8 | 14 | 57.1 | 1.00 |
Red-bellied Woodpecker | 17 | 33 | 51.5 | 10 | 22 | 45.5 | 0.78 |
Blue Jay | 16 | 33 | 48.5 | 13 | 28 | 46.4 | 1.00 |
American Crow | 22 | 33 | 66.7 | 16 | 28 | 57.1 | 0.60 |
Tufted Titmouse | 16 | 33 | 48.5 | 17 | 28 | 60.7 | 0.44 |
White-breasted Nuthatch | 15 | 27 | 55.6 | 7 | 20 | 35.0 | 0.24 |
Brown-headed Cowbird | 14 | 33 | 42.4 | 14 | 28 | 50.0 | 0.61 |
Common Grackle | 18 | 33 | 54.5 | 17 | 28 | 60.7 | 0.80 |
Northern Cardinal | 20 | 33 | 60.6 | 14 | 28 | 50.0 | 0.45 |
House Sparrow | 16 | 33 | 48.5 | 16 | 27 | 59.3 | 0.45 |
Brown Thrasher | 12 | 31 | 38.7 | 12 | 24 | 50.0 | 0.43 |
$ Includes only surveys where at least one individual was counted in year -1. # Comparisons by Fisher exact tests. |
TABLE A3. Range-level analysis comparing the number and proportion of surveys where birds declined between year –1 and year 0 within the range of Brood X and those outside of but within 50 km of Brood X.
Within range of Brood X$ | Outside range of Brood X$ | ||||||
Species |
N surveys declining |
Total surveys conducted |
% surveys declining |
N surveys declining |
Total surveys conducted |
% surveys declining |
P # |
American Kestrel | 36 | 53 | 67.9 | 20 | 37 | 54.1 | 0.19 |
Red-headed Woodpecker | 18 | 32 | 56.2 | 18 | 28 | 64.3 | 0.60 |
Red-bellied Woodpecker | 46 | 83 | 55.4 | 35 | 72 | 48.6 | 0.42 |
Blue Jay | 46 | 92 | 50.0 | 45 | 96 | 46.9 | 0.77 |
American Crow | 61 | 90 | 67.8 | 47 | 97 | 48.5 | 0.008 |
Tufted Titmouse | 56 | 90 | 62.2 | 44 | 87 | 50.6 | 0.13 |
White-breasted Nuthatch | 34 | 64 | 53.1 | 26 | 58 | 44.8 | 0.37 |
Brown-headed Cowbird | 40 | 91 | 44.0 | 36 | 88 | 40.9 | 0.76 |
Common Grackle | 49 | 92 | 53.3 | 48 | 96 | 50.0 | 0.67 |
Northern Cardinal | 49 | 92 | 53.3 | 52 | 98 | 53.1 | 1.00 |
House Sparrow | 55 | 90 | 61.1 | 47 | 88 | 53.4 | 0.36 |
Brown Thrasher | 39 | 79 | 49.4 | 38 | 76 | 50.0 | 1.00 |
$ Includes only surveys where at least one individual was counted in year -1. # Comparisons by Fisher exact tests. |
TABLE A4. Season-level analyses comparing the number and proportion of BBS routes where birds declined between year –1 and year 0 vs. the number and proportion of CBC sites conducted during the prior winter where birds declined. (Note: the BBS data are identical to the “within range of Brood X” half of TABLE A3)
BBS routes$ | CBC sites$ |
|
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Species |
N surveys declining |
Total surveys conducted |
% surveys declining |
N surveys declining |
Total surveys conducted |
% surveys declining |
P # |
American Kestrel | 36 | 53 | 67.9 | 35 | 71 | 49.3 | 0.04 |
Red-headed Woodpecker | 18 | 32 | 56.2 | 24 | 42 | 57.1 | 1.00 |
Red-bellied Woodpecker | 46 | 83 | 55.4 | 34 | 71 | 47.9 | 0.42 |
Blue Jay | 46 | 92 | 50.0 | 30 | 71 | 42.3 | 0.35 |
American Crow | 61 | 90 | 67.8 | 37 | 71 | 52.1 | 0.05 |
Tufted Titmouse | 56 | 90 | 62.2 | 46 | 71 | 64.8 | 0.75 |
White-breasted Nuthatch | 34 | 64 | 53.1 | 41 | 71 | 57.7 | 0.61 |
Brown-headed Cowbird | 40 | 91 | 44.0 | 34 | 52 | 65.4 | 0.02 |
Common Grackle | 49 | 92 | 53.3 | 35 | 50 | 70.0 | 0.07 |
Northern Cardinal | 49 | 92 | 53.3 | 50 | 71 | 70.4 | 0.04 |
House Sparrow | 55 | 90 | 61.1 | 42 | 71 | 59.2 | 0.87 |
Brown Thrasher | 39 | 79 | 49.4 | 14 | 18 | 77.8 | 0.04 |
$ Includes only surveys where at least one individual was counted in year -1. # Comparisons by Fisher exact tests. |