Fig. 3: Classification of evolved alternative provisioning patterns.

A Classification of the six evolutionary attractors in terms of the evolved values \(({\alpha }_{m},{\beta }_{m},{\alpha }_{f},{\beta }_{f})\) that determine the male and female negotiation strategies. This figure was created in Adobe Illustrator and the vector images were taken from Adobe Stock. B The six alternative attractors induce distinct provisioning patterns that are illustrated in panels P1–P4. Each panel shows one representative simulation. The sub-panels to the left show the evolved behavioural reaction norms of the male (blue) and female (red) parent and a cobweb that indicates the resulting sequence of provisioning rates. Starting at the green dot in the centre of the cobwebs, the yellow dots represent the provisioning rates in the course of the negotiation process. The subpanels to the right show the provisioning patterns of a randomly chosen pair of parents throughout the provisioning period. In (P1), both parents feed their offspring at a similar and roughly constant rate throughout the care period (‘egalitarian care’). In (P2), one sex (here: the female) feeds at a maximal rate, while the other sex feeds at a much lower rate (‘sex-biased care’). In (P3), one sex (here: the male) feeds again at a maximal rate, but the other sex does not feed the offspring at all (‘uniparental care’). In (P4), both sexes oscillate between provisioning at maximal and minimal rates; they do so in synchrony (‘oscillatory care’).