The relationship between brood care and environmental unpredictability in the desert isopod Hemilepistus reaumuri.

During the gestation period, mean above ground activity is short (males 23 min, females 17 min). Isopods allocated most of their above ground activity to foraging and feeding; only a small fraction was spent carrying food from the soil surface to subterranean burrows. There was a marked change in the activity pattern during the brood care period. Males and females increased their above ground activity 5.2 and 7.6 times, respectively. Most of the activity time (82.0, 86.3%) consisted of collecting and carrying soil crust and plants from the soil surface into burrows to feed the young. Up to 48 food items were carried by the same individual per day. The profit in fitness to the isopods, in the unpredictable desert environment, from a high investment in the offsprings is discussed.-from Authors