Appendix 1Sample Sizes Per Study Area

Appendix 1Sample sizes per study area

App. 1Overview on study areas and sample sizes per study area and spatial scale. The column sample size shows number of pre-breeding territories (and associated control areas; number before comma) and number of breeding territories (and associated control areas; number after comma) per study area. Elevation given as mean elevation above sea level.

Study area number / Study area / Mean coordinates / Elevation (m) / Size (km2) / Sample size
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16 / Bänkerjoch AG
Belchen SO
Blauen BL
Dittingen BL
Ennenda GL
Erschwil SO
Gündelhart TG
Homberg SO
Hochwald SO
Kleinlützel SO
Langenbruck BL
Lauwil BL
Montsevelier JU
Oltingen BL
Staffelegg SO
Scheltenpass SO / 645'144 / 254'539
627'988 / 245'763
605'989 / 256'391
603'249 / 254'717
725'218 / 211'059
608'659 / 247'056
712'618 / 278'229
631'140 / 245'407
616'881 / 256'293
599'946 / 254'110
626'575 / 245'376
616'981 / 247'025
604'131 / 246'345
638'000 /253'403
647'810 / 253'757
613'382 / 243'854 / 682
1,022
727
620
708
712
543
861
711
640
938
990
676
732
620
97 / 1.15
0.18
2.21
0.67
0.74
1.28
1.33
1.19
1.06
0.85
0.67
0.52
2.35
0.44
1.75
1.14 / 1,1
2,2
3,3
1,1
2,2
2,2
1,1
3,5
3,3
8,14
5,5
9,11
8,9
1,1
2,2
15,15

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Appendix 2Correlation coefficients of the RS variables

App. 2Spearman's rank correlation coefficients (rs) of the RS variables. Above the diagonal: breeding territories and field-absences (N = 156), below the diagonal: pre-breeding territories and pseudo-absences (N=132). Correlations ≥ |0.50| are printed in bold

dist_f / forest_type / r_march / slope / meanCC_20m / meanCC_15m / meanCC_10m / meanCC / pen5_1 / pen10_2 / pen50_2 / sdCH>3m / sdCH / sdVH / VH95 / maxVH / meanCH>3m / meanVH>3m / meanVH<3m / meanCH / meanVH
meanVH / 0.2 / -0.1 / -0.2 / -0.3 / 0.7 / 0.7 / 0.5 / 0.3 / 0.1 / 0.2 / -0.5 / 0.0 / -0.0 / 0.6 / 0.8 / 0.7 / 0.8 / 0.8 / -0.0 / 0.8 / -
meanCH / 0.2 / 0.1 / -0.2 / -0.2 / 0.9 / 0.9 / 0.6 / 0.2 / 0.3 / 0.5 / -0.1 / -0.0 / 0.0 / 0.9 / 0.9 / 0.8 / 1.0 / 1.0 / -0.2 / - / 0.8
meanVH<3m / -0.1 / -0.3 / -0.0 / 0.2 / -0.1 / -0.3 / -0.3 / -0.1 / -0.7 / -0.5 / -0.3 / 0.5 / 0.2 / -0.2 / -0.1 / 0.1 / -0.2 / -0.2 / - / -0.3 / -0.2
meanVH>3m / 0.2 / 0.1 / -0.3 / -0.2 / 0.9 / 0.8 / 0.4 / 0.0 / 0.4 / 0.6 / 0.1 / -0.0 / 0.2 / 0.9 / 0.9 / 0.9 / 1.0 / - / -0.3 / 0.8 / 0.7
meanCH>3m / 0.2 / 0.1 / -0.3 / -0.3 / 0.9 / 0.8 / 0.4 / 0.1 / 0.3 / 0.6 / 0.0 / 0.0 / 0.2 / 0.9 / 1.0 / 0.9 / - / 1.0 / -0.3 / 0.9 / 0.7
maxVH / 0.1 / -0.0 / -0.3 / -0.2 / 0.8 / 0.5 / 0.1 / -0.1 / 0.0 / 0.3 / -0.0 / 0.4 / 0.4 / 0.8 / 0.9 / - / 0.6 / 0.6 / 0.0 / 0.4 / 0.4
VH95 / 0.1 / 0.0 / -0.3 / -0.2 / 0.9 / 0.7 / 0.3 / -0.0 / 0.2 / 0.4 / -0.0 / 0.2 / 0.3 / 0.9 / - / 0.9 / 0.8 / 0.8 / -0.1 / 0.6 / 0.6
sdVH / 0.1 / 0.2 / -0.2 / -0.2 / 0.9 / 0.6 / 0.2 / -0.1 / 0.3 / 0.6 / 0.3 / 0.1 / 0.3 / - / 0.9 / 0.8 / 0.9 / 0.9 / -0.2 / 0.7 / 0.5
sdCH / -0.1 / -0.2 / -0.2 / -0.0 / 0.1 / -0.3 / -0.7 / -0.8 / -0.3 / -0.1 / 0.2 / 0.8 / - / 0.6 / 0.6 / 0.7 / 0.3 / 0.4 / 0.1 / -0.1 / -0.0
sdCH>3m / -0.1 / -0.2 / -0.2 / 0.0 / 0.0 / -0.4 / -0.6 / -0.5 / -0.5 / -0.4 / -0.0 / - / 0.8 / 0.3 / 0.6 / 0.7 / 0.1 / 0.1 / 0.4 / -0.2 / -0.1
pen50_2 / -0.1 / 0.4 / 0.2 / 0.2 / 0.0 / -0.0 / -0.2 / -0.4 / 0.4 / 0.6 / - / 0.2 / 0.4 / 0.3 / 0.1 / 0.1 / 0.1 / 0.1 / -0.1 / 0.2 / -0.6
pen10_2 / 0.1 / 0.4 / 0.1 / 0.0 / 0.5 / 0.6 / 0.4 / 0.0 / 0.8 / - / 0.5 / -0.4 / -0.1 / 0.5 / 0.2 / 0.1 / 0.6 / 0.6 / -0.6 / 0.5 / 0.2
pen5_1 / 0.2 / 0.3 / 0.0 / -0.1 / 0.3 / 0.5 / 0.5 / 0.2 / - / 0.9 / 0.3 / -0.5 / -0.2 / 0.3 / 0.1 / -0.1 / 0.4 / 0.4 / -0.8 / 0.4 / 0.1
meanCC / 0.1 / 0.2 / 0.2 / -0.1 / 0.2 / 0.5 / 0.8 / - / 0.2 / 0.1 / -0.5 / -0.6 / -0.8 / -0.2 / -0.3 / -0.4 / -0.0 / -0.1 / -0.1 / 0.4 / 0.3
meanCC_10m / 0.2 / 0.3 / 0.1 / -0.1 / 0.5 / 0.8 / - / 0.9 / 0.5 / 0.4 / -0.4 / -0.7 / -0.8 / 0.0 / -0.1 / -0.3 / 0.3 / 0.3 / -0.4 / 0.6 / 0.5
meanCC_15m / 0.2 / 0.3 / -0.0 / -0.1 / 0.8 / - / 0.8 / 0.6 / 0.5 / 0.6 / -0.2 / -0.5 / -0.4 / 0.4 / 0.3 / 0.0 / 0.6 / 0.6 / -0.4 / 0.8 / 0.6
meanCC_20m / 0.1 / 0.2 / -0.1 / -0.1 / - / 0.7 / 0.4 / 0.1 / 0.3 / 0.5 / -0.0 / 0.0 / 0.2 / 0.9 / 0.8 / -0.6 / 0.9 / 0.9 / -0.2 / 0.9 / 0.7
slope / -0.2 / 0.3 / 0.5 / - / -0.2 / -0.0 / 0.1 / 0.2 / -0.2 / -0.1 / -0.0 / -0.1 / -0.3 / -0.3 / -0.3 / -0.1 / -0.3 / -0.3 / 0.4 / -0.1 / -0.2
r_march / -0.1 / 0.6 / - / 0.4 / -0.2 / 0.2 / 0.3 / 0.4 / 0.1 / 0.1 / 0.0 / -0.4 / -0.5 / -0.4 / -0.5 / -0.6 / -0.3 / -0.3 / 0.0 / -0.1 / -0.2
forest_type / 0.0 / - / 0.6 / 0.3 / 0.0 / 0.3 / 0.4 / 0.4 / 0.2 / 0.2 / 0.1 / -0.4 / -0.5 / -0.1 / -0.3 / -0.4 / -0.1 / -0.1 / -0.1 / 0.1 / -0.1

Appendix 3Correlation coefficients RS variables and field variables

App. 3Spearman's rank correlation coefficients (rs) between RS and field variables (Pasinelli et al. 2016) for breeding territories and field-absences (N = 116): Correlations ≥ |0.50| are printed in bold

inclination / canopy cover / vegetation cover / nr. of tussocks / nr. of bushes / nr. of trees / amount of pole wood / nr. of immature trees / nr. of conifers / tree diversity / nr. of dead trees / nr. of trees branched below 4 m / nr. of trees branched below 10 m / average tree diameter / average crown contacts
meanVH / -0.34 / 0.08 / -0.16 / -0.40 / 0.03 / -0.36 / -0.36 / -0.35 / 0.14 / -0.06 / -0.15 / -0.45 / -0.44 / 0.53 / 0.06
meanCH / -0.26 / 0.14 / -0.25 / -0.47 / -0.03 / -0.45 / -0.51 / -0.32 / -0.16 / -0.27 / -0.22 / -0.54 / -0.52 / 0.58 / 0.14
meanVH<3m / 0.08 / 0.08 / -0.13 / -0.11 / 0.08 / 0.04 / 0.14 / -0.03 / 0.16 / 0.11 / -0.01 / 0.11 / 0.06 / -0.09 / 0.12
meanVH>3m / -0.27 / 0.10 / -0.22 / -0.44 / 0.00 / -0.49 / -0.55 / -0.33 / -0.20 / -0.32 / -0.25 / -0.57 / -0.56 / 0.58 / 0.12
meanCH>3m / -0.29 / 0.11 / -0.24 / -0.47 / -0.01 / -0.48 / -0.54 / -0.36 / -0.16 / -0.31 / -0.25 / -0.56 / -0.55 / 0.59 / 0.11
maxVH / -0.30 / 0.09 / -0.29 / -0.55 / 0.06 / -0.51 / -0.49 / -0.49 / -0.08 / -0.26 / -0.33 / -0.53 / -0.56 / 0.56 / 0.13
VH95 / -0.28 / 0.11 / -0.27 / -0.52 / 0.04 / -0.47 / -0.50 / -0.42 / -0.09 / -0.25 / -0.29 / -0.52 / -0.54 / 0.61 / 0.15
sdVH / -0.21 / 0.08 / -0.25 / -0.45 / 0.05 / -0.45 / -0.53 / -0.31 / -0.26 / -0.33 / -0.28 / -0.49 / -0.48 / 0.55 / 0.11
sdCH / -0.07 / -0.12 / -0.02 / -0.15 / 0.28 / -0.22 / -0.10 / -0.36 / 0.08 / -0.03 / -0.26 / -0.06 / -0.17 / 0.10 / -0.04
sdCH>3m / 0.01 / -0.07 / -0.11 / -0.23 / 0.30 / -0.19 / -0.01 / -0.37 / 0.12 / 0.08 / -0.27 / -0.01 / -0.12 / 0.05 / 0.08
pen50_2 / 0.19 / 0.00 / -0.08 / 0.03 / -0.03 / -0.04 / -0.13 / 0.13 / -0.51 / -0.30 / -0.04 / -0.00 / 0.02 / -0.07 / 0.06
pen10_2 / 0.04 / 0.19 / -0.16 / -0.14 / -0.17 / -0.23 / -0.41 / 0.05 / -0.48 / -0.40 / -0.11 / -0.34 / -0.27 / 0.26 / 0.17
pen5_1 / -0.00 / 0.07 / -0.01 / 0.04 / -0.17 / -0.16 / -0.34 / 0.08 / -0.27 / -0.22 / -0.09 / -0.26 / -0.19 / 0.26 / 0.07
meanCC / -0.07 / 0.19 / -0.11 / -0.10 / -0.18 / 0.06 / -0.00 / 0.13 / 0.01 / -0.02 / 0.11 / -0.08 / 0.01 / 0.08 / 0.09
meanCC_10m / -0.09 / 0.23 / -0.19 / -0.17 / -0.29 / -0.09 / -0.20 / 0.08 / -0.17 / -0.17 / 0.08 / -0.27 / -0.15 / 0.25 / 0.15
meanCC_15m / -0.13 / 0.24 / -0.29 / -0.35 / -0.25 / -0.30 / -0.43 / -0.09 / -0.27 / -0.28 / -0.04 / -0.46 / -0.37 / 0.47 / 0.21
meanCC_20m / -0.22 / 0.18 / -0.29 / -0.50 / -0.09 / -0.43 / -0.53 / -0.30 / -0.19 / -0.29 / -0.22 / -0.54 / -0.52 / 0.58 / 0.20
slope / 0.81 / 0.09 / -0.14 / 0.17 / -0.28 / 0.13 / 0.10 / 0.23 / -0.30 / 0.07 / 0.09 / 0.16 / 0.21 / -0.17 / 0.27
r_march / 0.41 / 0.17 / -0.11 / 0.16 / -0.28 / 0.19 / 0.10 / 0.30 / -0.31 / 0.00 / 0.03 / 0.17 / 0.24 / -0.12 / 0.27
forest_type / 0.20 / 0.12 / -0.10 / -0.05 / -0.22 / -0.02 / -0.01 / 0.12 / -0.49 / -0.22 / -0.10 / 0.01 / 0.03 / -0.12 / 0.13
dist_f / -0.02 / -0.07 / 0.02 / -0.02 / -0.00 / -0.09 / -0.10 / -0.05 / -0.13 / -0.14 / 0.02 / -0.12 / -0.14 / 0.12 / -0.07

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Appendix 4Results of within-group model selection

App. 4Results of within-group model selection for pre-breeding and breeding territories. Shown are best-supported models (ΔAICc = 0) and models with ΔAICc values < 2 to the best supported model per spatial scale. The quadratic effect of a variable, composed of a linear and a quadratic component (x ± x2), is denoted as (^2)

Pre-breeding territory models / ΔAICc / Breeding territory models / ΔAICc
Vegetation height
meanCH (^2), maxVH
meanCH (^2), maxVH (^2)
meanCH (^2), meanVH<3m, maxVH
meanCH (^2), meanVH<3m, maxVH (^2)
…
null model / 0
0.25
1.45
1.66
42.91 / meanVH, maxVH
meanVH<3m, VH95 (^2)
maxVH
meanVH<3m, maxVH (^2)
maxVH (^2)
…
null model / 0
0.22
0.44
1.41
1.82
51.14
Vertical diversity
sdVH, sdCH>3m
sdCH>3m
…
null model / 0
0.88
37.02 / sdVH, sdCH>3m
…
null model / 0
43.40
Vertical stratification
pen50_2, pen5_1
pen50_2 (^2), pen5_1
pen5_1
…
null model / 0
0.87
1.36
11.34 / pen50_2
null model
pen50_2 (^2) / 0
1.20
1.78
Canopy cover
meanCC_10m, meanCC_20m
meanCC_10m, meanCC_20m (^2)
…
null model / 0
1.58
58.80 / meanCC_10m, meanCC_20m
…
null model / 0
32.15
Geography
slope, r_march, dist_f
…
null model / 0
45.87 / slope, forest_type
slope
…
null model / 0
0.22
14.67

Appendix 5Accuracy measures

App. 5Model performance: area under the receiver operating characteristic curve (AUC) (±SD), true skill statistic (TSS) (±SD). All numbers are shown in %. The quadratic effect of a variable is denoted as (^2). Shown are best supported models (∆AICc values 2)

Models / AUC / TSS
Pre-breeding territories
sdVH, pen50_2, meanCC_10m, slope, r_march
pen50_2, meanCC_10m, meanCC_20m, slope, r_march
meanCC_10m, meanCC_20m, slope, r_march, dist_f
sdVH, pen50_2, meanCC_10m, slope, dist_f
pen5_1, meanCC_10m, meanCC_20m, slope, r_march / 91.9±2.5
92.2±2.5
93.2±2.2
91.6±2.5
92.2±2.4 / 75.8±5.6
75.8±5.7
75.8±5.6
71.2±6.1
77.3±5.5
Breeding territories
meanVH, sdCH>3m, slope
meanVH>3m, sdVH, sdCH>3m, pen50_2, slope
maxVH, sdCH>3m, pen50_2, slope
meanVH, meanVH<3m, sdCH>3m, slope
meanVH<3m, VH95 (^2), sdCH>3m, slope
meanVH<3m, maxVH, slope
meanVH, sdCH>3m, slope, forest_type / 85.4±3.0
85.5±3.1
84.7±3.1
86.1±3.0
84.8±3.1
83.9±3.2
86.0±2.9 / 62.8±6.2
61.5±6.3
60.3±6.2
66.7±5.9
59.0±6.4
59.0±6.4
65.4±6.0

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