By laying eggs in other birds’ nests, brood parasites avoid the costs of normal brooding. The result of this is that will lay more eggs per nesting season- more than 40 in case of the brown headed cowbird to make up for hosts that provide inadequate care. Additionally, by laying a single egg in many different nests, the parasite has increased the chances that at least one egg will escape predation than if all the eggs in a clutch were kept in the same nest. This is supported by the fact that brood parasitism is more prevalent in the tropics where nest predation is high.