Urine osmolality is equivalent to creatinine concentration for normalising urinary progestogen in the numbat (Myrmecobius fasciatus).

Urine was collected from numbats (Myrmecobius fasciatus) held at the Perth Zoo (Western Australian) as part of the native Species Breeding Programme which breeds animals in captivity to by released to the wild. Osmolality and creatinine concentrations were very variable despite the provision of water ad libitum and a controlled diet. Progestogen was normalised by dividing the concentration by both the creatinine concentration and the osmolality of the urine. The correlation of these two ratios was highly significant for 7 of the 9 animals.