Table 1.

Change in rejection rates of nonmimetic (redstart type or pied wagtail type) or mimetic (reed warbler type) model cuckoo eggs by reed warblers. Some mimetic eggs were inserted into nests after an adult cuckoo model was shown at the nest. Significant differences in rejection of nonmimetic eggs are tested using a binomial generalized model and a χ² distribution (df = 1) and responses to mimetic eggs are compared using Fisher’s exact tests. There was no difference in rejection rate of the two nonmimetic egg models (redstart or pied wagtail types, year*nonmimetic type: χ²₍₂₎ = 0.45, P = 0.80) so these were combined for comparisons among years

	Number of cuckoo eggs rejected/total
	Nonmimetic eggs			Mimetic eggs
Year	Redstart-type	Pied wagtail-type	Total	No adult cuckoo	After adult cuckoo
1985–1986	18/26	13/16	31/42	1/25	9/23
	(69.2%)	(81.3%)	(73.8%)	(4.0%)	(39.1%)
1997	14/57	18/69	32/126	6/39	5/30
	(24.6%)	(26.1%)	(25.4%)	(15.4%)	(16.7%)
2012	5/30	6/29	11/59	3/26	1/14
	(16.7%)	(20.7%)	(18.6%)	(11.5%)	(7.1%)
Overall effect of year			P<0.001	P=0.44	P=0.068
Change from 1985–1986 to 1997			P<0.001	P=0.23	P=0.12
Change from 1997–2012			P=0.31	P=0.73	P=0.65