Long-term survival of incipient colonies
After a month, only 154 out of the 1421 incipient colonies survived (10.84%), and only 85 survived until the fourth month (when the altricial larvae developed into workers able to provide care to both the parents and the next brood). Most of these colonies, 70 out of 85, survived until the end of the experiment (450 days, month 15). Similar to the short-term survival, no significant difference was observed between the survival of inbred and outbred pairings over the course of the experiment (P = 0.465; Figure 1b), while strong differences in survival were observed between specific pairings (Figure S5). Notably, the hazard ratio of the different pairing combinations at 14 days was significantly correlated to that at 450 days (P = 0.0009; Figure S6). This means that certain colony combinations were more likely to survive to both time points and that the development of brood and workers did not alter the ratio of surviving pairings after 14 days.