“The majority of roost trees are occupied by mixed groups of
adults, with territories comprised of a single male and one or more
females and their dependent young”
We commonly observed roost trees to be occupied by mixed groups of
sexes, with a single tree
occupied
by one or more males, and one or more females and their dependent young.
This is inconsistent with general knowledge based on historical studies
like Nelson (1965a) and Nelson (1965b), but consistent with more
contemporary observations (Table 2). We also observed cases where trees
were occupied by entirely male individuals (consistent with reports of
‘bachelor male’ trees in Markus (2002)). We would note here that a
single tree may contain multiple male territories (Markus 2002; Connell
2003) and the survey methods did not allow inference on the composition
of individual territories, only individual trees. The proportion of
males per tree appeared to follow seasonal patterns that was mostly
consistent between black and grey-headed flying-foxes within roosts
(Appendix S2). Some roosts (‘Toowoomba’, ‘Avondale’, ‘Lismore’) showed
an increase in the proportion of males per tree after parturition in
September/October, while other roosts (‘Sunnybank’, ‘Canungra’)
decreased immediately after this time. We also did not observe complete
segregation of sexes at any time of the year, in contrast to Nelson
(1965b) who noted complete segregation between September until early
December, and March to April.