The maintenance nitrogen requirement of the parma wallaby, Macropus parma, was found to be 566 mg per kg W*0.75 per day on a dietary basis, and 477 mg per kg W*0.75 per day on a truly digestible basis. This is similar to that of the red-necked pademelon, Thylogale thetis, another small wallaby which occupies a similar moist forest habitat, but much higher than (at least double) those of four other macropodid marsupials, all of which are from less mesic environments, that have been studied. Urea recycling decreased in response to water restriction in M. parma; in other published reports urea recycling did not change in T. thetis when water intake was restricted, but in three arid-adapted eutherian herbivores it increased. Voluntary intakes of dry matter and water by M. parma wefe also similar to those published for T. thetis, but higher than those of other macropodid species. These results support the hypothesis that within the Macropodidae nutrient requirements are linked closely with preferred habitat, regardless of phylogeny.