Effects of body size and weather on telomere length
Combining data from both populations (n =566), TL was found to be
negatively related to tarsus length (model ranked 1:βtarsus =-0.03, CI=[-0.05, -0.00], Tables 2
and 3, Fig. 5a) and positively related to the NAO_30 index
(βNAO_30 =0.10, CI=[0.01, 0.19], Fig. 5b).
This means that telomeres are shorter in larger individuals and when
overall weather conditions are harsh (Appendix S1). In addition, TLs
were shorter in females than males
(βfemale =-0.08, CI=[-0.14, -0.02]), and TLs
were shorter in the low population compared to the highpopulation (βlow =-0.17, CI=[-0.24, -0.10]).
The second-best model (∆AICc=0.2) showed weak evidence that the negative
relationship between TL and tarsus length tended to be steeper in thehigh population compared to the low population
(βlow*tarsus =0.05, CI=[-0.02, 0.11]),
suggesting that artificial selection for longer tarsus had a stronger
effect on TL compared to selecting for shorter tarsus. There was little
evidence for any effect of nestling age on TL (model ranked 3,
∆AICc=1.4, βage =0.01, CI=[-0.01, 0.03],
Table 2).