Brightness of melanin-based plumage coloration is a cue to oxidative stress in Himalayan Black Bulbuls (Hypsipetes leucocephalus nigerrimus)

Table 2 Multiple regressions of brightness in different body parts in 2010 and 2011

Parts	Terms	2010		2011
Parts	Terms	t ratio	p	t ratio	p
Back	Intercept	7.25	<.0001	29.49	<.0001
	Sex(F)	0.25	0.808	0.83	0.413
	Log(H/L ratio)^a	−0.05	0.964	−1.14	0.262
	Sex(F) × Log(H/L ratio)	−1.46	0.166	−1.49	0.144
Belly	Intercept	6.09	<.0001	24.15	<.0001
	Sex(F)	−1.37	0.194	1.53	0.134
	Log(H/L ratio)	0.78	0.447	−1.35	0.183
	Sex(F) × Log(H/L ratio)	−0.85	0.409	0.35	0.728
Breast	Intercept	9.00	<.0001	24.53	<.0001
	Sex(F)	0.65	0.525	0.93	0.358
	Log(H/L ratio)	0.19	0.853	−2.43	0.019*
	Sex(F) × Log(H/L ratio)	−1.44	0.172	−0.46	0.645
Forehead	Intercept	3.85	0.002	17.16	<.0001
	Sex(F)	1.52	0.150	−0.02	0.984
	Log(H/L ratio)	−0.49	0.635	−0.39	0.696
	Sex(F) × Log(H/L ratio)	−0.43	0.675	0.18	0.858
Nape	Intercept	7.03	<.0001	30.95	<.0001
	Sex(F)	−0.75	0.465	0.01	0.995
	Log(H/L ratio)	0.70	0.497	−0.62	0.539
	Sex(F) × Log(H/L ratio)	0.18	0.858	−1.2	0.238
Scapulars	Intercept	8.07	<.0001	40.47	<.0001
	Sex(F)	−2.22	0.043*	0.03	0.976
	Log(H/L ratio)	−1.01	0.329	−2.37	0.022*
	Sex(F) × Log(H/L ratio)	−0.76	0.461	−0.93	0.358
Remige	Intercept	5.70	<.0001	49.39	<.0001
	Sex(F)	−2.41	0.032*	0.59	0.555
	Log(H/L ratio)	−0.67	0.515	−0.28	0.782
	Sex(F) × Log(H/L ratio)	−1.60	0.133	−0.78	0.440
Tail	Intercept	6.23	<.0001	27.93	<.0001
	Sex(F)	0.31	0.759	2.1	0.042*
	Log (H/L ratio)	0.13	0.899	0.34	0.739
	Sex(F) × Log(H/L ratio)	1.01	0.330	−0.36	0.724

ISSN: 2053-7166