Kangaroo harvesters: fertilising the rangelands

Abstract

Offcuts from harvested red kangaroo (Macropus rufus), comprising the head, stomach, entrails, legs and joey (females only) and sometimes the tail remain near the point of harvest. Offcut weights of males averaged 11.46 kg and comprised 26% of the total body mass, whilst average female offcuts weighed 6.69 kg and comprised 31% of total body mass. There was a strong correlation between carcass and offcut mass for both sexes. Offcuts from 27 kangaroos were randomly exposed to three different assemblages of vertebrate scavengers. Soil nitrogen and organic carbon concentrations increased significantly following the addition of offcuts but there was no significant change in soil potassium concentrations or pH. Decomposition and dispersal of offcuts was enhanced by accessibility to different scavenging guilds. The contribution of the kangaroo industry to soil nutrient retention and cycling contrasts with the depletion of nutrients through the export of domestic livestock from the Australian rangelands.