Electronic Supplemental Material 3: Model selection
Stress hormones in relation to breeding status and territory location in colonial king penguin: a role for social density? By Viblanc, Gineste, Stier,
Robin & Groscolas
We report here additional information on competing models for explaining variation in plasmatic levels of baseline total corticosterone (CORT)
and oxidative stress markers (ROM, 8-OHdG and OXY) in incubating and chick-brooding king penguin. Note that oxidative stress markers were
only measured in chick-brooding birds due to limited volumes of plasma.
Model selection for baseline total corticosterone (CORT)
Tentative models for explaining variation in baseline total CORT levels in incubating and chick-brooding king penguins are given below. The
effects of: (1) breeding status, (2) the 3 principal components (PC1-3) characterizing the local social and climatic conditions of breeding
territories, (3) the interactions between breeding status and principal components, and (4) sampling date were considered. The best model (n° 67)
was selected as the one having the lowest AICc and BIC. If the ΔAICc between a model and the best fit was < 2, we retained the most
parsimonious one. Models in the table below are ordered by decreasing AICc. The number of parameters in the model is given by k. The
intercept only model (k = 0) is given for comparison.
N°
Model
k
R2
AICc
BIC
ΔAICc
1
PC2,PC3
2
0.00
698.25
709.09
60.11
2
PC3
1
0.00
696.19
704.37
58.04
3
PC2
1
0.00
696.11
704.30
57.97
4
Intercept only
0
0.00
694.08
699.57
55.93
5
PC1,PC2,PC3
3
0.09
688.90
702.36
50.75
6
PC1,PC3
2
0.09
686.80
697.64
48.66
7
PC1,PC2
2
0.09
686.72
697.56
48.58
8
PC1
1
0.09
684.67
692.85
46.52
9
PC2,PC3,Sample date
3
0.16
678.94
692.39
40.79
10
PC3,Sample date
2
0.16
676.89
687.73
38.75
11
PC2,Sample date
2
0.16
676.83
687.67
38.68
12
Sample date
1
0.16
674.82
683.00
36.67
13
PC1,PC2,PC3,Sample date
4
0.24
669.28
685.32
31.13
14
PC1,PC3,Sample date
3
0.24
667.19
680.65
29.04
15
PC1,PC2,Sample date
3
0.24
667.14
680.59
28.99
16
PC2,PC3,Breeding status,PC2*Breeding status,Sample date
5
0.28
666.00
684.58
27.85
17
PC1,Sample date
2
0.24
665.08
675.92
26.94
18
PC2,PC3,Breeding status,Sample date
4
0.27
664.29
680.33
26.15
19
PC2,PC3,Breeding status,PC2*Breeding status
4
0.27
664.12
680.16
25.98
20
PC2,Breeding status,PC2*Breeding status,Sample date
4
0.27
664.09
680.13
25.94
21
PC2,PC3,Breeding status
3
0.27
662.38
675.84
24.24
22
PC2,Breeding status,Sample date
3
0.27
662.20
675.66
24.05
23
PC3,Breeding status,Sample date
3
0.27
662.15
675.61
24.00
24
PC2,Breeding status,PC2*Breeding status
3
0.27
662.15
675.61
24.00
25
PC2,PC3,Breeding status,PC2*Breeding status,PC3*Breeding status,Sample date
6
0.31
662.04
683.12
23.89
26
PC2,PC3,Breeding status,PC3*Breeding status,Sample date
5
0.30
661.84
680.42
23.70
27
PC3,Breeding status,PC3*Breeding status,Sample date
4
0.29
660.80
676.84
22.65
28
PC3,Breeding status
2
0.27
660.31
671.15
22.17
29
PC2,Breeding status
2
0.27
660.28
671.12
22.13
30
Breeding status,Sample date
2
0.27
660.10
670.93
21.95
31
PC2,PC3,Breeding status,PC2*Breeding status,PC3*Breeding status
5
0.31
659.81
678.39
21.66
32
PC2,PC3,Breeding status,PC3*Breeding status
4
0.30
659.63
675.67
21.48
33
PC3,Breeding status,PC3*Breeding status
3
0.29
658.72
672.18
20.57
34
Breeding status
1
0.27
658.24
666.43
20.10
35
PC1,PC2,PC3,Breeding status,PC2*Breeding status,Sample date
6
0.38
648.59
669.67
10.44
36
PC1,PC2,PC3,Breeding status,PC2*Breeding status
5
0.38
648.07
666.65
9.92
37
PC1,PC2,PC3,Breeding status,Sample date
5
0.38
647.16
665.73
9.01
38
PC1,PC2,Breeding status,PC2*Breeding status,Sample date
5
0.38
646.90
665.48
8.76
39
PC1,PC2,PC3,Breeding status
4
0.37
646.47
662.51
8.33
40
PC1,PC2,Breeding status,PC2*Breeding status
4
0.37
646.12
662.16
7.98
41
PC1,PC2,PC3,Breeding status,PC1*Breeding status,PC2*Breeding status,Sample date
7
0.41
645.25
668.79
7.10
42
PC1,PC2,Breeding status,Sample date
4
0.38
645.14
661.17
6.99
43
PC1,PC3,Breeding status,Sample date
4
0.38
644.96
660.99
6.81
44
PC1,PC2,PC3,Breeding status,PC1*Breeding status,PC2*Breeding status
6
0.40
644.60
665.68
6.46
45
PC1,PC3,Breeding status
3
0.37
644.39
657.85
6.24
46
PC1,PC2,Breeding status
3
0.37
644.35
657.80
6.20
47
PC1,PC2,PC3,Breeding status,PC3*Breeding status,Sample date
6
0.41
644.21
665.29
6.06
48
PC1,PC2,PC3,Breeding status,PC1*Breeding status,Sample date
6
0.41
643.87
664.95
5.73
49
PC1,PC2,PC3,Breeding status,PC2*Breeding status,PC3*Breeding status,Sample date
7
0.42
643.68
667.22
5.54
50
PC1,PC2,Breeding status,PC1*Breeding status,PC2*Breeding status,Sample date
6
0.41
643.58
664.66
5.44
51
PC1,PC3,Breeding status,PC3*Breeding status,Sample date
5
0.40
643.17
661.75
5.02
52
PC1,PC2,PC3,Breeding status,PC1*Breeding status
5
0.40
643.06
661.64
4.91
53
PC1,Breeding status,Sample date
3
0.38
642.98
656.44
4.83
54
PC1,PC2,PC3,Breeding status,PC3*Breeding status
5
0.40
642.70
661.27
4.55
55
PC1,PC2,Breeding status,PC1*Breeding status,PC2*Breeding status
5
0.40
642.67
661.25
4.52
56
PC1,Breeding status
2
0.37
642.30
653.14
4.15
57
PC1,PC2,PC3,Breeding status,PC2*Breeding status,PC3*Breeding status
6
0.42
642.27
663.35
4.12
58
PC1,PC3,Breeding status,PC3*Breeding status
4
0.39
642.05
658.09
3.90
59
PC1,PC2,Breeding status,PC1*Breeding status,Sample date
5
0.41
641.83
660.41
3.69
60
PC1,PC3,Breeding status,PC1*Breeding status,Sample date
5
0.41
641.66
660.24
3.51
61
PC1,PC3,Breeding status,PC1*Breeding status
4
0.40
640.97
657.01
2.82
62
PC1,PC2,Breeding status,PC1*Breeding status
4
0.40
640.91
656.95
2.76
63
PC1,PC2,PC3,Breeding status,PC1*Breeding status,PC3*Breeding status,Sample date
7
0.44
640.49
664.03
2.34
64
PC1,PC2,PC3,Breeding status,PC1*Breeding status,PC2*Breeding status,PC3*Breeding status,Sample
8
0.45
639.70
665.66
1.55
date
65
PC1,Breeding status,PC1*Breeding status,Sample date
4
0.41
639.66
655.70
1.51
66
PC1,PC3,Breeding status,PC1*Breeding status,PC3*Breeding status,Sample date
6
0.43
639.60
660.69
1.46
67
PC1,Breeding status,PC1*Breeding status
3
0.40
638.86
652.31
0.71
68
PC1,PC2,PC3,Breeding status,PC1*Breeding status,PC3*Breeding status
6
0.43
638.84
659.92
0.69
69
PC1,PC3,Breeding status,PC1*Breeding status,PC3*Breeding status
5
0.42
638.36
656.94
0.21
70
PC1,PC2,PC3,Breeding status,PC1*Breeding status,PC2*Breeding status,PC3*Breeding status
7
0.45
638.15
661.69
0.00
Model selection for oxidative stress
Tentative models for explaining variation in the plasma levels of reactive oxygen metabolites
(ROM), 8-hydroxy-2'-deoxyguanosine (8-OHdG) (free radical-induced oxidative lesions on
DNA), and plasma antioxidant capacity (OXY) of chick-brooding birds are given below. The
effects of the 3 principal components (PC1-3) characterizing the local social and climatic
conditions of king penguin breeding territories, and sampling date, were considered. The best
models (n° 16, 32, 48) with the lowest AICc and BIC only retained the intercept and no
significant independent variable. Models in the table below are ordered by decreasing AICc
for ROM, 8-OHdG and OXY, respectively. The number of parameters in the model is given
by k.
N°
Model
k
R2
AICc
BIC
ΔAICc
1
Prin1,Prin2,Prin3,datePS
4
0.07
71.44
75.43
9.47
2
Prin2,Prin3,datePS
3
0.02
69.74
73.67
7.77
3
Prin1,Prin3,datePS
3
0.07
68.18
72.11
6.21
4
Prin1,Prin2,datePS
3
0.07
68.17
72.11
6.20
5
Prin1,Prin2,Prin3
3
0.07
68.17
72.10
6.20
6
Prin2,Prin3
2
0.00
67.21
70.79
5.24
7
Prin2,datePS
2
0.02
66.76
70.35
4.79
[ROM]
8
Prin3,datePS
2
0.02
66.76
70.35
4.79
(mg H2O2/dL)
9
Prin1,datePS
2
0.07
65.25
68.84
3.28
10
Prin1,Prin2
2
0.07
65.19
68.78
3.22
11
Prin1,Prin3
2
0.07
65.19
68.78
3.22
12
Prin3
1
0.00
64.49
67.49
2.52
13
Prin2
1
0.00
64.48
67.47
2.51
14
datePS
1
0.02
64.03
67.02
2.06
15
Prin1
1
0.07
62.51
65.50
0.54
16
Intercept only
0
0.00
61.97
64.16
0.00
17
Prin1,Prin2,Prin3
3
0.03
129.64
133.26
7.51
18
Prin1,Prin2,Prin3,datePS
4
0.17
128.86
132.43
6.73
19
Prin1,Prin3,datePS
3
0.09
127.95
131.57
5.82
[8-OHdG]
20
Prin2,Prin3,datePS
3
0.10
127.74
131.36
5.61
(ng/mL)
21
Prin1,Prin3
2
0.01
127.14
130.50
5.01
22
Prin1,Prin2
2
0.02
126.88
130.24
4.75
23
Prin2,Prin3
2
0.02
126.85
130.21
4.72
24
Prin1,Prin2,datePS
3
0.13
126.77
130.39
4.64
25
Prin3,datePS
2
0.04
126.35
129.72
4.22
26
Prin2,datePS
2
0.06
125.82
129.18
3.69
27
Prin1,datePS
2
0.09
124.92
128.28
2.79
28
Prin3
1
0.00
124.65
127.49
2.52
29
Prin2
1
0.01
124.44
127.29
2.31
30
Prin1
1
0.01
124.37
127.21
2.24
31
datePS
1
0.04
123.64
126.48
1.51
32
Intercept only
0
0.00
122.13
124.22
0.00
33
Prin1,Prin2,Prin3,datePS
4
0.01
268.22
272.21
11.27
34
Prin1,Prin2,datePS
3
0.00
265.11
269.04
8.16
35
Prin2,Prin3,datePS
3
0.01
264.97
268.90
8.02
36
Prin1,Prin3,datePS
3
0.01
264.95
268.88
8.00
37
Prin1,Prin2,Prin3
3
0.01
264.95
268.88
8.00
38
Prin1,datePS
2
0.00
262.20
265.79
5.25
39
Prin2,datePS
2
0.00
262.14
265.73
5.19
[OXY]
40
Prin1,Prin2
2
0.00
262.14
265.73
5.19
(μM HClO/ mL)
41
Prin3,datePS
2
0.01
261.99
265.58
5.04
42
Prin2,Prin3
2
0.01
261.99
265.58
5.04
43
Prin1,Prin3
2
0.01
261.96
265.55
5.01
44
datePS
1
0.00
259.47
262.47
2.52
45
Prin1
1
0.00
259.46
262.46
2.51
46
Prin2
1
0.00
259.41
262.40
2.46
47
Prin3
1
0.01
259.25
262.25
2.30
48
Intercept only
0
0.00
256.95
259.13
0.00