Consumption of milk by quokka (Setonix brachyurus) young

Abstract

We investigated the consumption of milk by the young quokka using the stable isotope deuterium oxide. The volume of milk consumed increased from 1.6 mL day–1 at 55 days post partum to 32.5 mL day–1 at 165 days. The daily energy intake ranged from ~22 to 151 kJ day–1 during pouch life. The crude growth efficiency (grams of growth per millilitre of milk consumed) increased from an average of 0.35 to 0.46 g mL–1 in the early stages of pouch life, and then decreased to 0.24 g mL–1 during Phase 2b of lactation. The crude growth efficiency measured in our study indicates that quokkas are equally efficient in converting milk energy to body mass as other marsupials reported in the literature. Measuring milk intake with this method offers a non-toxic, minimally invasive alternative to other techniques for measuring milk consumption in marsupials, when milk is the only source of water intake.