EFFECTS OF A SEVERE DROUGHT ON MORPHOLOGY OF ADRENAL-GLANDS AND OTHER INDEXES OF HEALTH IN RED KANGAROO MEGALEIA-RUFA (DESMAREST) IN NORTHWESTERN NEW-SOUTH-WALES

Drought adversely affects health and reproduction in red kangaroos (M. rufa). There is a significant drop in body weight in adult kangaroos, and growth rates of pouch young are depressed. In adult males both lobes of the pituitary gland decrease in size. All zones in the adrenal glands become smaller and lipid stores increase. In adult females the posterior lobe of the pituitary increases in size and, although all zones in the adrenal glands shrink, the evidence suggests continued stimulation of the zonae fasciculata and glomerulosa. The decrease in size of the adrenal glands is accompanied by cortical folding and nodulation and other structural changes. Growth curves of pouch young are shown to fit the Johnson-Schumacher curve Y = A * exp [-b/(x + k)]. The data substantiate the findings of earlier workers but suggest that anestrous female red kangaroos suckling small young may be better adapted to withstand drought than males.