Table 2.

Cox proportional hazards models for latency to arrive at tables

Variable	Minimal model
rho	χ2	P
Condition
Litter	0.065	0.82	0.366
Natural	−0.167	9.89	0.002
Novel	0.028	0.14	0.705
Species group (Corvid)	0.192	12.55	<0.001
Habitat (Urban)	−0.085	02.09	0.149
Region (Cornwall)	0.116	5.41	0.020
Corv_before	0.237	14.37	<0.001
Time	−0.168	7.61	0.006
Condition*Habitat
Litter*Urban	−0.243	21.61	<0.001
Natural*Urban	0.045	0.70	0.402
Novel*Urban	−0.055	0.64	0.425

Corv_before denotes whether a corvid species had arrived beforehand. Significant P values (P < 0.05) are highlighted in bold. The control condition was the reference category for all object conditions, rural areas for the urban gradient and Cambridgeshire for the region. See Appendix Table A6 for model with nonsignificant terms.