Experimental set-up
We trapped 20 male and 20 female adult Village weavers using mist nets
around the A. P. Leventis Ornithological Research Institute’s (APLORI)
Amurum Forest Reserve (AFR) (09° 87′ N, 08° 97′ E), Nigeria between
October and November 2020. Each bird was fitted with a uniquely numbered
metal ring and a combination of three colour rings. Birds were housed in
groups of 10 of equal sexes in four adjacent outdoor aviaries at the
APLORI. The aviaries measured 3 × 1 × 2 m with a concrete floor, a metal
frame, wire mesh, and a thatched roof made from grass mats. Birds were
fed grains, insects, and fruits for two weeks before the commencement of
the experiment which lasted a further eight weeks. Birds were randomly
assigned to aviaries and diet treatments were assigned to aviaries
systematically; with each set of two adjacent aviaries having alternate
diet treatments. Birds in two aviaries were fed crushed grains and
fruits, while the other two were fed crushed grains and insects. 200 g
of each food types were provided in separate trays placed side by side.
Food and water were provided ad libitum . All birds were weighed
(±0.1 g), scored for pectoral muscle and fat, and sampled for blood to
measure PCV and HBC before the diet restriction commenced. Subsequently,
birds were sampled fortnightly over 8 weeks. Sampling took place on two
consecutive days during each session, with two aviaries of alternate
diet treatments sampled per day in a rotating order (Nwaogu et
al., 2020).