Chang et al. • ALTITUDINAL CHANGES OF 5 15 N AND 5 13 C IN MONTANE BIRDS 39 
All species combined for insectivores 
Green-backed Tit 
(C) Green-backed Tit 
-20 
(H) Green-backed Tit 
_ -22 
o 
o 
cT -24 
O 
(2) a x P(3) 
(17) 
$2 -26 
S 13 C = -1.58 x Alt - 20.26 (R 2 = 0.03, P = 0.42) 
8 15 N = -3.93 x Alt + 14.81 (R 2 = 0.04, P = 0.39) 
CO 
Kruskal-Wallis test; H 2 = 0.94, P = 0.63 
-28 
Kruskal-Wallis test; H 2 = 3.36, P = 0.19 
0.5 1 1.5 2 2.5 3 0.5 1 1.5 2 2.5 3 
Rufous-capped Babbler 
12 
FIG. 4. Change in 8 ,5 N and 5 ,3 C values of feathers of insectivorous birds with altitude in Taroko National Park, 
Taiwan. Results of all species combined are shown in A and D. Results of individual species are shown in B, C, E and F. 
Stable isotope values of all individuals of each species collected at the same sites are expressed as means ± SE. Numbers of 
feathers used for isotope analyses for each species at different sites are in parentheses. Numbers of feathers used for isotope 
analyses for all species combined correspond to those of each species at different sites. One-way ANOVA results are also 
presented. Asterisks indicate significant differences (P < 0.05) between sites. 
