Table 3.

Factors affecting the probability of association between parakeets and storks in rural areas. Relative importance of predation risk, conspecific aggregation and substrate on the probability of protective nesting associations between Monk parakeets Myiopsitta monachus and white storks Ciconia ciconia. Estimates and 95% confidence intervals (2.5 and 97.5%) were assessed after model averaging (ΔAIC ≤2). We considered that a given variable has no, weak or strong support when the 95% confidence interval strongly overlapped zero, barely overlapped zero (*), or did not overlap zero (**), respectively. Models were run separately for 2014 and 2015. k: number of parameters. AICc: Akaike Information Criterion corrected for small sample sizes. ΔAICc: difference between the AICc of model i and that of the best-supported model (i.e. the model with the lowest AICc); w: Akaike weights. R²: measure of how well the model explains the data

Model 2014	k	AICc	∆AICc	weight	Variables	Estimate	2.50%	97.50%
predation risk + conspecific density	3	107.56	0.00	0.67	predation risk	−3.70	−5.47	−1.94	**
predation risk + conspecific density + substrate	5	108.94	1.38	0.33	conspecific density	2.69	1.56	3.81	**
conspecific density + substrate	4	128.75	21.19	0.00	substrate (pylon)	15.22	− 2533.35	2563.80
conspecific density	2	133.87	26.31	0.00	substrate (tree)	16.21	− 2532.36	2564.79
predation risk + substrate	4	173.90	66.34	0.00
predation risk	2	180.08	72.52	0.00
substrate	3	183.32	75.76	0.00
	1	202.61	95.04	0.00
Model 2015	k	AICc	∆AICc	weight	Variables	Estimate	2.50%	97.50%
conspecific density + substrate	4	101.07	0.00	0.36	conspecific density	2.02	1.19	2.84	**
conspecific density	2	101.39	0.32	0.31	substrate (pylon)	18.40	−13,219.31	13,256.10
predation risk + conspecific density	3	102.34	1.26	0.19	substrate (tree)	1.63	−13,742.57	13,745.84
predation risk + conspecific density + substrate	5	102.87	1.80	0.15	predation risk	−0.75	−2.75	1.25
predation risk + substrate	4	149.78	48.71	0.00
substrate	3	159.11	58.04	0.00
predation risk	2	164.26	63.18	0.00
	1	193.96	92.88	0.00

2014: R² = 0.39

2015: R² = 0.40