Sti number o( arthropods/100 g of dry foliage for most abundant arthropod Orders by period and net location in a bottomland forest during 2001-2002, South 
Moorman et al. • SEASONAL BIRD USE OF HABITATS AND ARTHROPODS 
35 
35 
CO C3 
< -M 
H i 
u 
noonNno;- 
pi o o' o' - c o 
+1 +l +1 +1 +1 +1 +1 
it) —• —• e-J rn rn 
rri c- ci O fri rj O 
<S 
m co c-. ri r<-, O' — 
piddd-od 
+1 +1 +1 +1 +1 +1 +1 
no o -r p iri r'l 
h d — o i- c-i o 
r'. oc m ri r^iO' — 
riddd-do 
+1 +1 +1 +1 +1 +1 +1 
— —; r- 'C ci rn p 
rir^dd-rid 
O' 00 C-l — O' N f*-, 
Noodd-d 
+1 +1 +1 +1 +1 +1 +1 
p ci ri ci —■ re rj 
d oc — d ci <r, —’ 
o 
O' x ci — O' ci ci 
ci d d d d d 
+1 +1 +1 +1 +1 +1 +1 
- it, m ci o rs — 
fd ici — d ci rr, — 
O' oo Cl — O' ci rc, 
ci o o o o - o 
+1 +1 +1 +1 +1 +1 +1 
-C <r, on -f P rcj p 
d d c o o ri — 
— no 'c, -r -t -t-r 
ci d d d —< d d 
+1 +1 +1 +1 +1 +1 +| 
n co 0 "t rt c, o 
- c in -t -t *t n 
ri o d o •- d d 
+1 +1 +1 +1 +1 +1 +1 
© ir-, O' oo i~~ Vi oc 
-4 c-; — ori-- 
- « m Nf t t t 
ci d d d — d d 
41 +1 fl +1 +1 +1 +1 
— cj r-; v, — p p 
x iri — ci rn d ci 
CVVCOOCINO — — 
-ddddod 
+1 +1 +1 +1 +1 +1 +1 
S; oc t in O -t ci 
ci ci -4 o ci d d 
C, NO X Cl NO — — 
— d d d d d d 
+1 +1 +1 +1 +1 +1 +1 
C, Tf c Cl Ci Cl Cj 
O'" ci ci d ci d d 
rc. 'O OC Cl NC 
-dcdd 
+1 +1 +1 +1 +1 
C C O d oo 
■c — ci d d 
i 
o 
2 2 
■S s c. E. £ 
e o o o -j 
:S5|| 
< < CJ X X 
+1 -H 
— o 
d d 
c. 'j •- 
- o. fl 
0 Cl 
— O 
'£. ■= 
j 6 
TABLE 3. Relationship between foliage-gleaning bird 
captures (mist-net captures/100 net hrs) and foliage¬ 
dwelling arthropods in a bottomland hardwood forest on 
the Savannah River Site, South Carolina, 2001-2002. 
Positive or negative relationships are indicated in 
parentheses. 
Independent variables' 
F 
df 
p 
All arthropods (-) 
0.5 
1/33 
0.49 
All arthropods*period (+) 
5.4 
3/33 
0.004 
Spring (-) 
1.2 
33 
0.29 
Breeding (+) 
18.5 
33 
<0.001 
Post-breeding (+) 
9.4 
33 
0.004 
Fall (-) 
5.4 
33 
0.03 
Lepidoptera (-) 
1.2 
1/33 
0.28 
Arthropod*period (—) 
1.6 
3/33 
0.21 
11 The arthropod variables were tested against bird abundance in a model 
which also included period and net location as fixed effects to control for their 
influence Only the results for arthropod variables and their interactions with 
period ate provided 
Coleoptera in proportions greater than expected 
based on availability during all seasons (Moorman 
et al. 2007). Yet, foliage-dwelling Coleoptera were 
more abundant in the forest understory than in the 
gaps during all seasons, suggesting birds were not 
tracking important arthropod food resources. 
We documented relationships between birds 
and arthropods during the breeding, post-breeding, 
and fall migration periods. However, the observed 
patterns may be artifacts of different and indepen¬ 
dent habitat associations of birds and arthropods. A 
positive correlation occurred when habitat associ¬ 
ations of birds and arthropods were consistent 
with each other and, when inconsistent, there was a 
negative correlation. Conversely, the positive 
relationships between foliage-gleaning birds and 
foliage-dwelling arthropods during the breeding 
and post-breeding periods may indicate arthropod 
food resources are more important during these 
TABLE 4. Relationship between foliage-gleaning bird 
captures (mist-net captures/100 net hrs) and understory (0- 
3 m) vegetation density in a bottomland hardwood forest on 
the Savannah River Site. South Carolina. 2001-2002. 
Numerator DF is 1 and denominator DF is 26 for each 
category. 
Period 
F 
P 
Spring (+) 
131.4 
<0.t)01 
Breeding (+) 
22.6 
<0.001 
Post-breeding (+) 
17.1 
<0.001 
Full (+) 
47.1 
<0.001 
