Effects of diet on body condition
The weavers which fed on grains and fruits significantly lost more body
mass between week 0 (before diet restriction) and week 8 (at the end of
diet restriction) compared to the weavers that were fed on grains and
insects (Fig. 2A, F 4, 183 = 2.63, p = .036, Table 2).
This pattern was similar between sexes (Fig. 2B, F 1,
183 = 1.17, p = .282, Table 2 & Table S3B). Body mass decreased
significantly upon diet restriction (between week 0 and week 2) only in
weavers fed on grains and fruits, but weavers fed on grains and insects
maintained their body masses throughout the experiment (Fig. 2A, Table
S3A) and this was similar for males and females (Fig. 2B, F4, 183 = 1.29, p = .275, Table 2 & Table S4).
Muscle size was similar between the weavers fed on grains and fruit, and
those fed on grains and insects before diet restriction in week 0 (Fig.
3A), but upon diet restriction, the muscle size of the weavers fed on
grains and fruits significantly became lower than those fed on grains
and insects (Fig. 3A, F 4, 183 = 8.32, p <
.001, Table 2) and this pattern differed marginally between sexes (Fig.
3B, F 1, 183 = 3.04, p = .083, Table 2 & Table S3B):
females deprived of insects lost more pectoral muscle mass than males of
the same group. Muscle size decreased significantly after diet
restriction in week 6 (t = 6.88, p < .000, Table S3A), and 8
(t = 3.70, p = .010, Table S3A) in the weavers fed on grains and fruits,
but weavers fed on grains and insects maintained their muscle sizes
throughout the experiment (Fig. 3A, Table S3A). This pattern was similar
for males and females (Fig. 3B, F 4, 183 = 1.76, p =
.138, Table 2 & Table S4).
Overall, the fat score was similar between the weavers fed on grains and
fruits, and those fed on grains and insects before diet restriction in
week 0 (Fig. 4A). After diet restriction, the weavers fed on grains and
insects significantly accumulated more fat compared to the weavers fed
on grains and fruits (Fig. 4A) but, this was sex dependent (Fig. 4B, F1, 183 = 4.26, p = .040, Table 2). As such, fat scores
did not differ significantly (t = - 0. 05, p = .000) between diet
treatments for females but, males fed on grains and insects accumulated
more fat than those fed on grains and fruits (Fig. 4B, t = - 2. 94, p =
.019, Table S3B). For both treatments, fat reserve increased after diet
restriction from week 2 – 8 and differed between weeks (Fig. 4A, F1, 184 = 3.31, p = .012, Table 2 & Table S3A) and this
was similar for males and females (F 1, 183 = 1.30, p =
.273, Table 2 & Table S4).
Diet treatment had no effect on PCV (F 1, 183 = 0.06, p
= .808, Table 3), however, PCV increased significantly over the course
of the experiment in both diet treatments (Fig. 5A, F 4,
183 = 12.54, p < .001, Table 3 & Table S5) and this was
similar for males and females (Fig. 5B, F 4, 183 = 0.09,
p = .986, Table 3).
Similarly, diet had no effect on HBC (F 1, 183 = 0.28, p
= .597, Table 2), but HBC increased significantly during the experiment
in both diet treatments (Fig. 6A, F 4, 183 = 16.34, p
< .001, Table 3 & Table S5). This pattern was similar between
sexes (Fig. 6B, F 4, 183 = 0.09, p = .985, Table 3).