Table 2. Generalized linear models of fertility (n = 1312) and potential litter size (n = 1280) of subadult and adult roe deer females in Slovenia (2013–2015).

The independent variables were age (yearlings vs. adults), body mass (covariate), body mass × age interaction, and year (2013, 2014 vs. 2015; fixed factor). Model selection was performed by the Akaike information criteria (AIC). For the best model, basic statistics are displayed, while for other models with ΔAIC < 2 only the model structure and ΔAIC are shown.

Fertility (best model) = f (age + body mass + age × body mass + year); AIC = 246.2; p << 0.001
	Estimate	Standard error	Wald value		P value
Age (yearlings vs. adults)	-4.727	1.244	14.4		<<0.001
Body mass	0.416	0.094	19.6		<<0.001
Body mass × age (yearlings vs. adults)	0.332	0.094	12.5		<<0.001
Year (2013 vs. 2015)	-0.781	0.285	7.5		0.006
Year (2014 vs. 2015)	-0.409	0.281	2.1		0.146
Other models with ΔAIC < 2: none
Potential litter size (best model) = f (age + body mass + age × body mass); AIC = 2023.3; p << 0.001
	Estimate	Standard error		Wald value	P value
Age (yearlings vs. adults)	-0.279	0.178		2.5	0.117
Body mass	0.035	0.012		8.5	0.004
Body mass × age (yearlings vs. adults)	0.014	0.012		1.4	0.243
Other models with ΔAIC < 2: f (age + body mass), ΔAIC = 0.5; f (age + body mass + year), ΔAIC = 1.9