Hard times in the city – attractive nest sites but insufficient food supply lead to low reproduction rates in a bird of prey

Table 3 Dependence of breeding parameters (2010–2012, N = 157) on the urban gradient (measured as percentage of sealed soil in r = 500 m around the nest site) as fixed effect in a generalized linear mixed model (GLMM)

Breeding parameter	Estimate	SE	Z-value	*Pr(>\|z\|)*	R²for GLMM	Sign.
Clutch size ( N = 138)					4.5
Laying date^‡	−0.01	0.00	−2.48	0.0132		*
(Intercept)	1.54	0.04	38.80	<0.0001		***
Hatching rate					15.44
Laying date^‡	−0.04	0.01	−2.94	0.0033		**
Sealed soil	−2.40	1.07	−2.23	0.0255		*
(Intercept)	2.54	0.78	3.24	0.0012		**
Fledging rate					16.04
Laying date^‡	−0.04	0.02	−2.06	0.0399		*
Sealed soil	−2.13	1.25	−1.71	0.0882		•
(Intercept)	2.60	0.99	2.62	0.0087		**
Fledged brood size					32.31
Laying date^‡	−0.02	0.00	−4.54	<0.0001		***
Sealed soil	−0.85	0.34	−2.48	0.0131		*
(Intercept)	1.26	0.25	5.04	<0.0001		***

The nest site ID and the study year were included as random factors. The error family was chosen according to the type of response variable.
Note:’^‡’ data presented as residuals with the study year.
Significance codes: ‘***’ 0.001, ‘**’ 0.01, ‘*’ 0.05, ‘•’ <0.1.

ISSN: 1742-9994