Table 2.

Linear mixed effects model for the timing of breeding (lay period) in relation to (a) the urban gradient (1–78% urban cover); and (b) nest type (nest boxes versus other), nearest neighbour distance (log transformed) and weather conditions during the egg-laying period (spring). Estimated lay period of 53 and 24 peregrine territories, respectively, over 26 years (1989–2014) on the Cape Peninsula.

(a) all nests n = 399 lay period	estimate	SE	t-value	χ2	df	P-value
Intercept	0.28	0.74	0.37	0.14	1	0.708
Urban gradient	-0.34	0.07	-4.83	23.31	1	<0.001
Nearest neighbour distance	-0.03	0.21	-0.13	0.02	1	0.895
Pc1 lay period (cold/wet–warm/dry)	-0.11	0.04	-3.08	9.47	1	0.002
Pc2 lay period (warm/wet–cold/dry)	-0.08	0.05	-1.74	3.01	1	0.083
(b) urban nests n = 188 lay period	estimate	SE	z-value	χ2	df	P-value
Intercept	-1.61	1.19	-1.35	1.82	1	0.177
Urban gradient	0.03	0.11	0.29	0.08	1	0.772
Nest type (nest box) †	-0.41	0.20	-2.08	4.33	1	0.037
Nearest neighbour distance	0.51	0.33	1.55	2.40	1	0.121
Pc1 lay period (cold/wet–warm/dry)	-0.11	0.05	-2.39	5.69	1	0.017
Pc2 lay period (warm/wet–cold/dry)	-0.13	0.06	-2.28	5.20	1	0.023

† Nest type ‘other’ were used as a reference category. Pc1: negative values: cold and wet weather conditions; positive values: warm and dry weather conditions; Pc2: negative values: warm and wet weather conditions; positive values: cold and dry weather conditions. See full matrix of factor loadings of PCA in supplementary material S3.