TABLE 1.

Coefficients for linear regression models between richness and evenness indices and bird sampling age^a

Body site and index	Flock	b	A	R2	df	v	t	P value
Richness
Cecum	F1	20.7	79.6	0.863	51	1.33	1.07	0.224
	F2	16.4	103	0.663	51	2.68
Ileum	F1	13.6	20.2	0.549	39	3.90	0.70	0.310
	F2	8.32	37.2	0.26	44	4.48
Nasal cavity	F1	−0.24	105	0.00159	33	1.10	9.97	1.73E−14
	F2	6.23	56	0.53	33	1.04
Trachea	F1	4.3	59	0.0561	21	14.8	1.09	0.217
	F2	3.77	25.6	0.0851	19	8.04
Evenness
Cecum	F1	0.00475	0.698	0.196	51	1.81E−06	3.12	0.004
	F2	0.00916	0.647	0.227	51	5.60E−06
Ileum	F1	0.0216	0.482	0.337	39	2.35E−05	0.34	0.375
	F2	0.00966	0.5	0.077	44	2.54E−05
Nasal cavity	F1	−0.00268	0.645	0.0351	33	5.98E−06	9.49	1.20E−13
	F2	0.0101	0.573	0.5	33	3.09E−06
Trachea	F1	0.0116	0.425	0.0163	21	3.87E−04	0.65	0.319
	F2	0.00629	0.371	0.00723	19	2.86E−04

^aCoefficients given are slope (b), y intercept (A), and coefficient of determination (R²). Also given are the degrees of freedom for the group (df = n − 1), variance around the slope (v; see function 1), and an associated value for Student’s t test comparing the two slopes (t; see function 2), from which a P value is derived.