Table 2. GLM predicted effects of supplementary feeding treatment and environmental variables on laying date in reed warblers.

Parameter	Estimate ± SE	F	P
April temp	-2.94 ± 0.60	75.03	<0.0001
Rain	-0.04 ± 0.01	40.56	<0.0001
Invert avail.	0.27 ± 0.11	5.85	0.0181
Reed height	0.11 ± 0.05	10.35	0.0020
Treatment	16.00 ± 7.97	0.78	0.3796
Treatment × April temp	-1.90 ± 0.88	4.71	0.0333