Ecological Archives E096-008-A1
He Zhang, Oscar Vedder, Peter H. Becker, and Sandra Bouwhuis. 2015. Contrasting between- and within-individual trait effects on mortality risk in a long-lived seabird. Ecology 96:71–79. http://dx.doi.org/10.1890/14-0064.1
Appendix A. Contrasting between- and within-individual trait effects on mortality risk in a long-lived seabird.
Supplementary information regarding the between- and within-individual effects of ten phenotypic traits on mortality risk in the Common Tern, with descriptive statistics of the ten phenotypic traits (Table A1), information on our assessment of death (Table A2), quantification of between-trait correlations (Table A3), model comparison of models used to select forms of sex, recruitment age and frailty prior to assessing trait effects on mortality risk (Table A4) and a report on the estimated effects of the traits on mortality risk (Table A5).
Table A1. Descriptive statistics (mean and SD) for raw data, between- and within-individual components of each phenotypic trait.
Trait |
Raw data |
Between- |
Within- |
Age-corrected within- |
||||
|
mean |
SD |
mean |
SD |
mean |
SD |
mean |
SD |
Arrival date |
120.60 |
12.65 |
120.60 |
7.93 |
0.00 |
9.86 |
0.00 |
8.33 |
Arrival mass |
130.93 |
8.29 |
130.93 |
6.47 |
0.00 |
5.19 |
0.00 |
5.16 |
Breeding probability |
0.90 |
0.31 |
0.90 |
0.21 |
0.00 |
0.23 |
0.00 |
0.23 |
Laying date |
142.78 |
12.43 |
142.78 |
7.58 |
0.00 |
9.86 |
0.00 |
8.10 |
Egg volume |
38.50 |
2.72 |
38.50 |
2.07 |
0.00 |
1.76 |
0.00 |
1.71 |
Clutch size |
2.52 |
0.63 |
2.52 |
0.34 |
0.00 |
0.52 |
0.00 |
0.50 |
Brood size |
1.83 |
1.07 |
1.83 |
0.58 |
0.00 |
0.90 |
0.00 |
0.90 |
Hatching success |
0.74 |
0.36 |
0.74 |
0.19 |
0.00 |
0.31 |
0.00 |
0.30 |
Rearing success |
0.44 |
0.38 |
0.44 |
0.19 |
0.00 |
0.33 |
0.00 |
0.32 |
No. of fledglings |
0.69 |
0.80 |
0.69 |
0.38 |
0.00 |
0.70 |
0.00 |
0.70 |
Table A2. Assessment of the reliability of assuming a bird to be dead after not having observed it, based on the observation histories up to 2013 of 782 common terns that bred between 1993 and 2011: after first reproduction, 96% of breeders do not skip observation for two or more consecutive years.
Max. no. of consecutive gaps |
No. of birds |
% of birds |
0 |
732 |
93.6 |
1 |
20 |
2.6 |
2 |
14 |
1.8 |
3+ |
16 |
2.0 |
Table A3. Between-trait correlations for the between- (lower triangular matrix) and within-individual trait components (upper triangular matrix). Reported are the correlation coefficient r and p value obtained using Kendall's method, as well as, between brackets, the r² value based on the Pearson correlation coefficient. Note that, for the within-individual components, only one combination of records was randomly selected for each individual to calculate the correlation to avoid bias due to the fact that individuals differ in their number of within-individual observations due to variation in lifespan.
Arrival date |
Arrival mass |
Breeding probability |
Laying date |
Egg volume |
Clutch size |
Brood size |
Hatching success |
Rearing success |
No. of fledglings |
|||||||||||
|
r (r²) |
p |
r (r²) |
p |
r (r²) |
p |
r (r²) |
p |
r (r²) |
p |
r (r²) |
p |
r (r²) |
p |
r (r²) |
p |
r (r²) |
p |
r (r²) |
p |
Arrival date |
|
|
-0.078 (0.014) |
0.032 |
-0.013 (0.013) |
0.649 |
0.435 (0.333) |
<0.001 |
-0.195 (0.083) |
<0.001 |
-0.203 (0.101) |
<0.001 |
-0.224 (0.097) |
<0.001 |
-0.179 (0.056) |
<0.001 |
-0.152 (0.037) |
<0.001 |
-0.203 (0.068) |
<0.001 |
Arrival mass |
-0.181 (0.052) |
<0.001 |
|
|
-0.002 (0.001) |
0.969 |
-0.041 (0.003) |
0.270 |
0.042 (0.002) |
0.264 |
0.077 (0.014) |
0.042 |
0.074 (0.013) |
0.052 |
0.042 (0.006) |
0.259 |
0.009 (0.001) |
0.833 |
0.031 (0.006) |
0.409 |
Breeding probability |
-0.112 (0.034) |
<0.001 |
0.014 (0.001) |
0.641 |
|
|
-0.001 (0.001) |
0.981 |
0.069 (0.005) |
0.018 |
0.008 (0.001) |
0.800 |
0.016 (0.001) |
0.592 |
0.032 (0.001) |
0.281 |
-0.024 (0.001) |
0.453 |
-0.002 (<0.001) |
0.936 |
Laying date |
0.582 (0.624) |
<0.001 |
-0.165 (0.051) |
<0.001 |
-0.141 (0.048) |
<0.001 |
|
|
-0.267 (0.099) |
<0.001 |
-0.344 (0.271) |
<0.001 |
-0.306 (0.210) |
<0.001 |
-0.184 (0.109) |
<0.001 |
-0.185 (0.051) |
<0.001 |
-0.269 (0.127) |
<0.001 |
Egg volume |
-0.105 (0.036) |
<0.001 |
0.066 (0.015) |
0.011 |
0.049 (0.002) |
0.071 |
-0.077 (0.034) |
0.001 |
|
|
0.149 (0.032) |
<0.001 |
0.141 (0.031) |
<0.001 |
0.086 (0.019) |
0.001 |
0.037 (<0.001) |
0.192 |
0.132 (0.022) |
<0.001 |
Clutch size |
-0.237 (0.160) |
<0.001 |
0.114 (0.030) |
<0.001 |
0.059 (0.022) |
0.038 |
-0.358 (0.303) |
<0.001 |
0.001 (0.002) |
0.966 |
|
|
0.426 (0.321) |
<0.001 |
0.137 (0.059) |
<0.001 |
0.005 (0.001) |
0.872 |
0.176 (0.073) |
<0.001 |
Brood size |
-0.197 (0.088) |
<0.001 |
0.051 (0.007) |
0.055 |
0.046 (0.013) |
0.104 |
-0.328 (0.206) |
<0.001 |
0.021 (0.002) |
0.401 |
0.463 (0.353) |
<0.001 |
|
|
0.656 (0.720) |
<0.001 |
0.041 (0.004) |
0.151 |
0.336 (0.220) |
<0.001 |
Hatching success |
-0.080 (0.028) |
0.001 |
-0.015 (<0.001) |
0.568 |
0.043 (0.009) |
0.130 |
-0.167 (0.075) |
<0.001 |
0.019 (0.003) |
0.442 |
0.134 (0.047) |
<0.001 |
0.652 (0.699) |
<0.001 |
|
|
0.041 (0.002) |
0.156 |
0.269 (0.156) |
<0.001 |
Rearing success |
-0.163 (0.041) |
<0.001 |
0.088 (0.011) |
0.001 |
0.074 (0.010) |
0.011 |
-0.252 (0.078) |
<0.001 |
0.013 (<0.001) |
0.619 |
0.127 (0.019) |
<0.001 |
0.097 (0.013) |
<0.001 |
0.043 (0.005) |
0.098 |
|
|
0.376 (0.236) |
<0.001 |
No. of fledglings |
-0.204 (0.060) |
<0.001 |
0.081 (0.012) |
0.003 |
0.075 (0.012) |
0.009 |
-0.333 (0.151) |
<0.001 |
0.070 (0.006) |
0.005 |
0.279 (0.131) |
<0.001 |
0.437 (0.309) |
<0.001 |
0.315 (0.183) |
<0.001 |
0.558 (0.457) |
<0.001 |
|
|
Table A4. Generalized AIC values with degrees of freedom (df) between brackets, as obtained for models used to first select the best form for sex and recruitment age (RA; columns 1–4), then to select a frailty term (columns 5–6), before obtaining the results for effects of between- and within-individual effects (B and W, respectively) of 10 phenotypic traits on mortality risk in up to 782 common terns, as reported in table 1 in the main paper. The best performing models with the lowest AIC for each trait are indicated in bold. Note that sample sizes for each trait are identical to those presented in table 1 in the main manuscript and are therefore not reported here.
Model |
B+W |
B+W+ |
B*sex*RA+ |
B+W+ |
Frailty |
Frailty |
Arrival date |
4824 (2) |
4831 (9) |
4807 (23) |
3310 (2) |
3298 (110) |
3289 (11) |
Arrival mass |
2244 (2) |
2249 (9) |
2269 (23) |
1507 (2) |
1507 (2) |
1492 (12) |
Breeding probability |
5826 (2) |
5830 (9) |
5835 (23) |
4077 (2) |
4077 (2) |
4054 (12) |
Laying date |
4511 (2) |
4501 (9) |
4501 (23) |
3068 (2) |
3068 (2) |
3036 (13) |
Egg volume |
4741 (2) |
4740 (9) |
4744 (23) |
3302 (2) |
3302 (2) |
3288 (11) |
Clutch size |
4715 (2) |
4713 (9) |
4719 (23) |
3272 (2) |
3272 (2) |
3259 (11) |
Brood size |
4745 (2) |
4744 (9) |
4763 (23) |
3306 (2) |
3306 (2) |
3293 (11) |
Hatching success |
4780 (2) |
4780 (9) |
4801 (23) |
3343 (2) |
3343 (2) |
3329 (11) |
Rearing success |
3734 (2) |
3738 (9) |
3756 (23) |
2569 (2) |
2569 (2) |
2561 (8) |
No. of fledglings |
4751 (2) |
4750 (9) |
4764 (23) |
3312 (2) |
3312 (2) |
3299 (10) |
Table A5. Original (without separation of between- and within-individual trait components) as well as standardized effects for each of ten phenotypic traits on mortality risk in up to 782 common terns. Note that sample sizes and p values of the standardized effects are identical to those presented in table 1 in the main manuscript and are therefore not reported here.
|
Original effects without separation |
Standardized effects |
|||||||
Trait |
Between-individual effect |
Within-individual effect |
Age-corrected |
||||||
|
E |
SE |
p |
E |
SE |
E |
SE |
E |
SE |
Arrival date |
0.015 |
0.004 |
<0.001 |
0.488 |
0.044 |
-0.335 |
0.065 |
-0.256 |
0.063 |
Arrival mass |
-0.006 |
0.009 |
0.510 |
-0.203 |
0.073 |
0.193 |
0.074 |
0.127 |
0.074 |
Breeding probability |
-0.545 |
0.126 |
<0.001 |
0.053 |
0.048 |
-0.261 |
0.041 |
-0.214 |
0.041 |
Laying date |
-0.002 |
0.006 |
0.790 |
0.435 |
0.052 |
-0.893 |
0.089 |
-0.470 |
0.070 |
Egg volume |
0.006 |
0.019 |
0.750 |
-0.189 |
0.052 |
0.244 |
0.050 |
0.169 |
0.049 |
Clutch size |
0.015 |
0.091 |
0.870 |
-0.356 |
0.047 |
0.300 |
0.059 |
0.155 |
0.057 |
Brood size |
-0.014 |
0.051 |
0.780 |
-0.311 |
0.051 |
0.186 |
0.055 |
0.045 |
0.054 |
Hatching success |
-0.081 |
0.144 |
0.570 |
-0.171 |
0.048 |
0.077 |
0.052 |
0.006 |
0.052 |
Rearing success |
0.102 |
0.161 |
0.530 |
-0.283 |
0.059 |
0.216 |
0.060 |
0.011 |
0.060 |
No. of fledglings |
0.024 |
0.072 |
0.740 |
-0.318 |
0.057 |
0.193 |
0.057 |
0.004 |
0.056 |