Chang et al. • ALTITUDINAL CHANGES OF 5 15 N AND 5 13 C IN MONTANE BIRDS 41 
(A) All species combined for insectivores 
(6)t 
T l— 
I (8) 
- 4 —-< 
Wilk's X = 0.50 (18) 
F 14,226 = 6.59 V ’fy. 
p< 0.001 I < 41 ) 
(5) / x/4g\ 
(20) 
• Bulowan (339 m) 
O Siboa (956 m) 
A Loshao (1179 m) 
A Bilyu Sacred Tree (2231 m) 
▼ Guanyuan (2415 m) 
V Dayuling (2500 m) 
■ Hehuan Farm (2740 m) 
□ Siafongkou (2876 m) 
(D) Rufous-capped Babbler 
r 
Wilk's X = 0.21 | 
F 8,58 = 8-66 
P=< 0.001 
(4) 
I 
- * -, 
/ 
(7)h§h 
(3) 
( 8 ) 
/ 
li*Jl_*_J ( 
II 
II 
(E) White-browed Bush Robin 
Wilk's X = 
0.37 
f 4 .34 = 5.54 
P = 0.002 
r * 
“1 
1 
1 
5 ( 10 ) 
(3) 
^ (8) 
1-5-H 
-26 -24 -22 -20 
S 13 C (°/ 00 ) 
FIG. 6. MANOVA comparisons of sites of insectivorous birds. Results of all species combined are shown in A. Results 
of individual species are shown in B-E. Stable isotope values of all individuals collected at the same sites are expressed as 
means ± SE. Numbers of feathers used for isotope analyses at different sites are in parentheses. Asterisks indicate 
significant differences (P < 0.05) between sites. Results of post hoc test of A are in Appendix 2. 
(Fig. 5E), Steere’s Liocichla (Fig. 5F), Grey- 
hooded Fulvettas (Fig. 5G), Rufous-capped Bab¬ 
blers (Fig. 6D), and White-browed Bush Robins 
(Fig. 6E). The other four species did not differ 
across sites (Figs. 5B, C; 6B, C). 
Year-to-year and Within-year Comparisons .— 
Seven species had sufficient data for between- 
year (Fig. 7, Table 2) and six species for within- 
year (Fig. 7, Table 3) comparisons. Feathers for 
all species from the same individuals did not have 
significant between-year and within-year varia¬ 
tions in 8 I3 C. The power of the tests varied 
between 0.05 and 0.45. Feathers from the same 
individuals for 8 ,5 N values had no significant 
between-year and within-year variations in isoto¬ 
pic values for all species except Taiwan Yuhinas 
{F 1,9 = 13.1, P = 0.006), and Steere’s Liocichlas 
(F 1,13 = 4.9, P = 0.045). The 5 15 N values for 
