Under such circumstances the sexual activity of male animals is also depressed. This indicates that, although camel herds sustain fewer deaths during severe droughts than other types of livestock, they do suffer deferred effects, such as markedly lower calving rates in the following year. It also suggests that the low reproductive rates, which are frequently regarded as the great economic drawback of camels, are at least in part a sound and self-regulatory physiological adaptation that attunes their population sizes to fluctuating forage availability, preventing the overgrazing of resources.