Cooperation in the natural world can, at first glance, appear puzzling: why should an animal cooperate when doing so is costly, and would benefit a competitor? In this talk, I will address this question by investigating links between cooperation and animal health using field studies of wild birds and mammals. I will first test whether cooperatively breeding societies (whereby ‘helpers’ forego breeding and instead assist raising others’ young) are maintained because cooperation lightens overall workloads, improves health, slows ageing, and extends lifespans. I will focus on my studies of white-browed sparrow weavers (Plocepasser mahali) and meerkats (Suricata suricatta) in the Kalahari Desert. I will then contrast these findings with inter-species cooperation in greater honeyguides (Indicator indicator) in the Mozambican wilderness. In a remarkable human-wildlife mutualism, these birds actively call to humans searching for honey and lead them to the location of bees’ nests in return for a beeswax meal. I will explore how this unique case of human- wildlife cooperation is resilient to cheating honeyguides that scrounge a free piece of wax, and whether honeyguide cooperation is related to variation in individual health. Overall, these results suggest that cooperation can influence, and be driven by, variation in animal health, but that these effects must be viewed in the light of other ecological and social factors.