Territories and social interactions within the flying-fox summer camps vary depending on the social group to which an individual belongs, however overall males are dominant over females.  Originally, Nelson (1965) identified four distinct types of groups within a flying-fox colony including guard groups, family groups, adult groups, and juvenile packs, however some of those ideas have since been modified or discredited including the guard and family groups (V. Jones, 2008, personal communication).

Nelson’s (1965) description of the guard group included both sexes, however more males than females, and as being located on the outskirts of the colony.  He hypothesized that the members of this group are unsuccessful males who were unable to establish a territory and a harem of females.  The purpose of this group would be to alert other members of the colony of any threats such as predators (Nelson, 1965).  Instead, it seems more likely that all individuals participate in vigilence for predators.  Predators of flying-foxes include birds of prey, and therefore will not necessarily be spotted first by individuals on the outskirts of the colony (V. Jones, 2008, personal communication).  If a predator is spotted, an individual will make an alarm cry and vigilantly watch the predator’s actions (Nelson, 1965).

Nelson (1965) described family groups as consisting of a monogamous adult pair and their offspring and as being less aggressive and with larger territories than other groups. This idea, however, has been completed discredited.  First, females with offspring move about the camp freely and do not usually stay with their male mate.  Second, once a flying-fox is weaned, it does not stay with its mother (V. Jones, 2008, personal communication). 

Nelson (1965) originally described the adult flying-fox groups as containing either monogamous pairs of polygynous groups.  Nelson noted that the polygynous groups were usually at the center of the colony.  In addition, polygynous groups territories were small and aggression was at its highest, as the male must defend several females from other males (Nelson, 1965).  Since this observation, the idea of monogamous pairs has been invalidated.  What appear to be monogamous pairs in the colony are more likely to be a male who has attracted only one female as opposed to several females (V. Jones, 2008, personal communication).

Juvenile groups are comprised of a few adults and up to 50 juveniles, most of which are male.  In these groups there is no pronounced territorial behavior or aggression. Instead, the juveniles act in playful ways and often engage in mutual grooming (Nelson, 1965).  In addition, groups of young males will huddle very close together and “tussle” (V. Jones, 2008, personal communication).

Aggressive behavior in flying-foxes is most prominent during the establishment of mating territories in the summer camps, especially for the polygamous, harem-holding males.  This aggression, however, is extremely ritualized and rarely results in injury (Nelson, 1965).

The use of olfactory signals in the flying-fox is very prominent.  Territories are marked and defended using tree-marking, and partner smelling occurs before copulation.  Also, mothers identify their young through smell (Nelson, 1965).

Individual flying-foxes often shift location between different colony sites, which serves to provide more genetic variation within the colonies.  Harem-holding males, however, shift sites much less frequently than other individuals (Banack and Grant, 2002).