Table 2. Vocal responses of yellow warblers at Churchill to three models presented at the nest during the egg-laying stage (n = 17), and results of Friedman test and associated multiple comparisons.
	Model
Response	Cowbird	Jay	Sparrow	P
Seet	1.6 ± 1.1	3.1 ± 2.2	0.3 ± 0.3	0.2800
	0 (0 - 15)	0 (0 - 35)	0 (0 -5)
Chip	4.3 ± 1.8	10.5 ± 3.1	5.5 ± 2.4	0.2806
	0 (0 - 23)	3 (0 - 41)	0 (0 - 38)
Metallic chip	4.4 ± 4.4	1.6 ± 1.6	0	0.6202
	0 (0 - 74)	0 (0 - 28)	0
Warble	0	0.1 ± 0.1	0	0.3791
	0	0 (0 - 1)	0
Zeep	1.1 ± 0.8	1.2 ± 0.6	1.4 ± 1.1	0.8016
	0 (0 - 13)	0 (0 - 7)	0 (0 - 18)
Silent - female a	23.1 ± 2.3	20.4 ± 1.9	23.5 ± 2.2	0.2642
	28 (4 - 30)	20 (4 - 30)	27 (3 - 30)
- male	19.3 ± 2.8	16.3 ± 3.0	14.0 ± 3.1	0.3931
	19 (13 - 28)	18 (8 - 21)	16 (5 - 19)
Responses are given as mean ± s.e. (top row) and median (range) (bottom row). Conventions as in Table 1. a Sample sizes for female, n = 17 for all models; male, n = 4 for all models.