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Description
Probably the first group to come to mind when thinking of arboreal Australian mammals are the possums and of all the lineages originating from those Miocene treetops they were certainly the most successful survivors, remaining diverse right up to the Holocene. By the time glaciation returned the impacts of man had rendered nearly half of all possum species extinct, but nonetheless representatives of most groups managed to make it through and quickly rediversified once conditions stabilised. Possums are now such a hugely diverse group that trying to cover them all would be a strenuous task, but even among such variety there are standouts. For some their notability is apparent just from their appearance, like that pot-bellied eucalyptus specialist, the Colah, meanwhile for others it is less obvious until you take a closer look. One such possum is the Colonial Glider (Petaurus dominus).

The Colonial Glider is a petaurid, the family of possums that contains the most specious and successful lineage of gliding species all of which sit within the genus Petaurus, commonly referred to as the wrist-winged gliders. The Colonial Glider is a descendant of the Yellow-bellied Glider in particular, which was the largest of the Holocene petaurids and a native of the tall forests of the eastern seaboard. This was one of those species to see great success during the end-Holocene Climatic Optimum, spreading across much of the northern half of the continent as rainforest and other wet forest became widespread for a brief time. Of course this was not to last and once the glacial cycles returned and the forest once again disappeared under a sea of sand and spinifex, most gliders followed it back to the sanctuary of the east coast, however several populations managed to hang on in the dry eucalyptus forest just to the west of the Great Dividing Range where they did not formerly occur. These drier forests are by no means hostile to the survival of gliders given that several species, like the Squirrel and Sugar Gliders, already occurred here, but nonetheless they have far less resources than the forests that Yellow-bellied Gliders would usually inhabit and this spurred quite a significant change in behaviour. In the wet forests they usually inhabited Yellow-bellied Gliders were very tolerant of other possums and even shared the sap from the incisions in trees they made themselves with smaller petaurids and feathertail gliders, often feeding side by side. But now, with resources restricted, the gliders began to develop greater concern with the survival of their own kind than that of other possums and, being gregarious in the form of tightly knit family groups, began to use their size and numbers to drive all others out of a specific grove of trees they had declared as their own. Over time these dry forest gliders would build on this territorial behaviour and eventually develop a complex social system that has more in common with certain honeyeaters than other possums - aggressive colonialism.

The Colonial Glider today is found in tall dry eucalyptus forests just to the west of the Great Dividing Range, with any specific territory containing 20 to 80 animals origination from several different family groups that have united to form a colony. Within the centre of each colony is usually a grove of larger old growth trees which contain many hollows, which make the perfect nesting site. All of the gliders within a territory will return to this communal grove during the daylight hours to sleep, with three to seven individuals inhabiting any given hollow at the same time. Colonial Gliders emerge earlier in the evening than any other possums, just before the sun goes down when the lack of thermals means that eagles are no longer hunting, and this is solely so they get to respective feeding sites first. Each family group is assigned a specific area of the territory in which they feed and watch over, with each "zone" having enough plant diversity and resources to sustain them year round. The only time this changes is during particularly harsh droughts, when the assigned zones dissipate and each family group is allowed to feed freely amongst the colony in case their own zone no longer has enough to support them. Aside from this each family group tends to keep out of each other's zones, but all this changes once a potential competitor or predator is spotted. Yellow-bellied Gliders were among the most vocal of all marsupials and their bloodcurdling shrieks, hoots and rattles could travel for half a kilometre through the forest, and this trait has been put to great use by their descendants. The news of a threat travels swiftly throughout the colony and all available gliders will quickly converge on the site, their ability to glide for up to 150 metres through the trees meaning they can travel very swiftly through the canopy. They will all amass around an invader and at first do little but screech loudly and make mock charges in an attempt to scare it away, and often this is enough to make a predator or another possum turn tail and leave. However, with more persistent intruders they must instead resort to attack, with the gliders taking it in turns to distract the threat through intimidation while others to sneak in from behind to make quick bites with their incisors, leaping back quickly as the victim swings back to retaliate. By this point an intruder will invariably turn back, the gliders following it until it leaves the boundary of their territory.

Colonial Gliders are opportunistic breeders, with the coming of good rains (usually during the winter in the south and early summer in the north) sparking a synchronized breeding event amongst the colony. Gliders from different family groups will pair up in a temporary monogamous relationship, interacting with each other back at the communal grove before and after they go out to their assigned zone. The young will spend about 100 days in the pouch before they are left in a collective nursery hollow which a few gliders will always be left around to guard. Their diets span quite a variety of different foods including nectar, pollen, honeydew, insects and, especially during harsher times, tree sap extracted from eucalypts.

For the speculative evolution project Australia: The Next 54 Million Years. See more here: specevo.jcink.net/index.php?sh…

Description
Probably the first group to come to mind when thinking of arboreal Australian mammals are the possums and of all the lineages originating from those Miocene treetops they were certainly the most successful survivors, remaining diverse right up to the Holocene. By the time glaciation returned the impacts of man had rendered nearly half of all possum species extinct, but nonetheless representatives of most groups managed to make it through and quickly rediversified once conditions stabilised. Possums are now such a hugely diverse group that trying to cover them all would be a strenuous task, but even among such variety there are standouts. For some their notability is apparent just from their appearance, like that pot-bellied eucalyptus specialist, the Colah, meanwhile for others it is less obvious until you take a closer look. One such possum is the Colonial Glider (Petaurus dominus).

The Colonial Glider is a petaurid, the family of possums that contains the most specious and successful lineage of gliding species all of which sit within the genus Petaurus, commonly referred to as the wrist-winged gliders. The Colonial Glider is a descendant of the Yellow-bellied Glider in particular, which was the largest of the Holocene petaurids and a native of the tall forests of the eastern seaboard. This was one of those species to see great success during the end-Holocene Climatic Optimum, spreading across much of the northern half of the continent as rainforest and other wet forest became widespread for a brief time. Of course this was not to last and once the glacial cycles returned and the forest once again disappeared under a sea of sand and spinifex, most gliders followed it back to the sanctuary of the east coast, however several populations managed to hang on in the dry eucalyptus forest just to the west of the Great Dividing Range where they did not formerly occur. These drier forests are by no means hostile to the survival of gliders given that several species, like the Squirrel and Sugar Gliders, already occurred here, but nonetheless they have far less resources than the forests that Yellow-bellied Gliders would usually inhabit and this spurred quite a significant change in behaviour. In the wet forests they usually inhabited Yellow-bellied Gliders were very tolerant of other possums and even shared the sap from the incisions in trees they made themselves with smaller petaurids and feathertail gliders, often feeding side by side. But now, with resources restricted, the gliders began to develop greater concern with the survival of their own kind than that of other possums and, being gregarious in the form of tightly knit family groups, began to use their size and numbers to drive all others out of a specific grove of trees they had declared as their own. Over time these dry forest gliders would build on this territorial behaviour and eventually develop a complex social system that has more in common with certain honeyeaters than other possums - aggressive colonialism.

The Colonial Glider today is found in tall dry eucalyptus forests just to the west of the Great Dividing Range, with any specific territory containing 20 to 80 animals origination from several different family groups that have united to form a colony. Within the centre of each colony is usually a grove of larger old growth trees which contain many hollows, which make the perfect nesting site. All of the gliders within a territory will return to this communal grove during the daylight hours to sleep, with three to seven individuals inhabiting any given hollow at the same time. Colonial Gliders emerge earlier in the evening than any other possums, just before the sun goes down when the lack of thermals means that eagles are no longer hunting, and this is solely so they get to respective feeding sites first. Each family group is assigned a specific area of the territory in which they feed and watch over, with each "zone" having enough plant diversity and resources to sustain them year round. The only time this changes is during particularly harsh droughts, when the assigned zones dissipate and each family group is allowed to feed freely amongst the colony in case their own zone no longer has enough to support them. Aside from this each family group tends to keep out of each other's zones, but all this changes once a potential competitor or predator is spotted. Yellow-bellied Gliders were among the most vocal of all marsupials and their bloodcurdling shrieks, hoots and rattles could travel for half a kilometre through the forest, and this trait has been put to great use by their descendants. The news of a threat travels swiftly throughout the colony and all available gliders will quickly converge on the site, their ability to glide for up to 150 metres through the trees meaning they can travel very swiftly through the canopy. They will all amass around an invader and at first do little but screech loudly and make mock charges in an attempt to scare it away, and often this is enough to make a predator or another possum turn tail and leave. However, with more persistent intruders they must instead resort to attack, with the gliders taking it in turns to distract the threat through intimidation while others to sneak in from behind to make quick bites with their incisors, leaping back quickly as the victim swings back to retaliate. By this point an intruder will invariably turn back, the gliders following it until it leaves the boundary of their territory.

Colonial Gliders are opportunistic breeders, with the coming of good rains (usually during the winter in the south and early summer in the north) sparking a synchronized breeding event amongst the colony. Gliders from different family groups will pair up in a temporary monogamous relationship, interacting with each other back at the communal grove before and after they go out to their assigned zone. The young will spend about 100 days in the pouch before they are left in a collective nursery hollow which a few gliders will always be left around to guard. Their diets span quite a variety of different foods including nectar, pollen, honeydew, insects and, especially during harsher times, tree sap extracted from eucalypts.

For the speculative evolution project Australia: The Next 54 Million Years. See more here: specevo.jcink.net/index.php?sh…