Table 1.

Species used in analysis, with wintering zones derived from literature and recoveries of ringed birds and mean annual values and sample sizes for nesting parameters. Secondary wintering zones are given in parentheses where there is uncertainty over classification [11]. An unknown proportion of common chiffchaff and Eurasian blackcap winter north of the Sahara desert (northern).

species	wintering zone	first egg date (days from 1 January)		clutch size
		mean (s.e.)	N	mean (s.e.)	N
European turtle dove Streptopelia turtur	humid (arid)	167 (1.60)	12.2	1.96 (0.011)	11.3
sand martin Riparia riparia	arid	156 (3.90)	33.7	4.30 (0.16)	29.8
barn swallow Hirundo rustica	southern	169 (0.66)	200	4.52 (0.011)	454
wood warbler Phylloscopus sibilatrix	humid	143 (0.57)	34.2	5.71 (0.054)	18.3
common chiffchaff. Phylloscopus collybita	arid/northern	130 (0.97)	54.5	5.46 (0.026)	36.8
willow warbler Phylloscopus trochilus	humid	136 (0.50)	84.4	5.93 (0.026)	48.3
Eurasian blackcap Sylvia atricapilla	arid/northern	138 (0.92)	39.8	4.55 (0.017)	38.6
garden warbler Sylvia borin	humid	144 (0.69)	22.1	4.35 (0.033)	16.8
lesser whitethroat Sylvia curruca	arid	142 (0.75)	8.65	4.61 (0.056)	6.22
common whitethroat Sylvia communis	arid	147 (0.98)	20.1	4.68 (0.019)	31.0
sedge warbler Acrocephalus schoenobaenus	arid	148 (0.74)	47.0	5.02 (0.025)	34.9
Eurasian reed warbler Acrocephalus scirpaceus	humid (arid)	166 (0.79)	198	3.89 (0.013)	139
spotted flycatcher Muscicapa striata	humid	161 (0.43)	70.4	4.24 (0.014)	78.1
pied flycatcher Ficedula hypoleuca	humid	135 (0.62)	430	6.69 (0.034)	348
common redstart Phoenicurus phoenicurus	arid	137 (0.81)	62.7	6.21 (0.034)	49.0
whinchat Saxicola rubetra	humid	147 (0.52)	26.9	5.55 (0.051)	11.7
wheatear Oenanthe oenanthe	arid	136 (1.10)	13.7	5.37 (0.071)	11.2
yellow wagtail Motacilla flava	arid	147 (1.40)	5.86	5.14 (0.066)	5.38
tree pipit Anthus trivialis	humid	140 (0.79)	19.9	4.84 (0.055)	10.9