To determine whether the values obtained in assays vary in urban vs rural flying-foxes; to determine whether the levels of GCMs are related to the overall physical condition of animals; to develop a ‘remote’ method of testing the health of flying-foxes
Type of Study:
Urban flying-foxes had lower Body Condition Indexes and elevated levels of glucocorticoid metabolites: 75% had levels that were higher than the rural range and 30% were higher by an order of magnitude. Such elevated levels of glucocorticoid (‘stress’) hormones are characteristic of chronic stress. While urbanisation can cause chronic stress, given the low BCIs observed, it is more likely that food shortage was the major stressor in this study. Significantly different results were found between male and female urban flying-foxes: males were in relatively better condition than females but had higher levels of faecal glucocorticoid metabolites.
periurban/rural vs urban individuals
Management actions that act as stressors on a colony of flying-foxes in autumn and early winter when there is a prior cause of chronic stress, such as a food shortage, may have a disproportionately deleterious effect on the colony by elevating the stress responses of the adult males.
ANOVA, Tukey's, correlation
Periurban/rural flying foxes received supplementary food, had been hand-reared, and didn't require capture cf urban individuals which were mist-netted. RBG individuals may have arrived at the camp in response to food shortage elsewhere.
Matcham and Sydney, NSW
Response variable :
Faecal glucocorticoid metabolites levels, Body condition indexes
14 periurban/rural individuals, 20 urban individuals
Parry-Jones, K. A., Webster, K. N. (2016) Baseline levels of faecal glucocorticoid metabolites and indications of chronic stress in the vulnerable grey-headed flying-fox, Pteropus poliocephalus. Aust. Mammal.. 38, 195–203.