Table 1.

GAM test results of the relationship between LPAI virus infection of white-fronted geese and sampling date and bird characteristics.

		2005–2006		2006–2007		2007–2008		2008–2009
	d.f.	G	p	G	p	G	p	G	p
sex	1	2.70	0.100	0.70	0.396	1.00	0.317	0.58	0.448
age	1	7.95	0.005	16.19	<0.001	0.11	0.737	13.94	<0.001
wing length	1	0.03	0.872	2.42	0.128	2.95	0.086	1.41	0.235
body mass	1	0.03	0.868	0.10	0.747	0.05	0.829	10.32	0.001
spline (date)a		26.30	<0.001	6.70	0.010	12.44	<0.001	6.94	0.008

^aSpline (date) indicates the test statistics (G) of adding the final degrees of freedom (d.f.) that improved the fit of the model significantly (2005–2006, 1; 2006–2007, 2; 2007–2008, 8; 2008–2009, 8).