Barking isn’t what most glider owners think it is. Gliders are not talking to their humans when they bark, they are talking at other gliders, not with, just at.
Lots of Petaurus possums bark, though it sounds a bit different that our awesome possums. Here is what Australian ecologists think is the underlying evolutionary purpose for barking:
“…appears to regulate individual spacing by facilitating mutual avoidance, a function hypothesized to be an evolutionary precursor to the use of calls in territorial defense.” 2009 Australian Journal of Zoology 57(1) 55-64 https://doi.org/10.1071/ZO08075
Boring huh? Sure, but it’s damn useful too. Take note of that phrase, “facilitating mutual avoidance” because under those opaque polysyllabic curtains lies some interesting and exploitable glider behavior.
Barking is the perfect time to trim nails, especially using trim in the pouch type methods where they feel hidden. When a glider barks, other gliders will stop and listen. They will freeze up, sometimes they get tense and low to the ground, others they cling to the cage wall in a shadow. They are more reluctant to take a treat, even a mealworm, and when they do they often hold onto it in their mouth or hand waiting til the barking stops or chew extra slowly and quietly. They will be more likely to hide during barking and will use fast skittery motions to get to a place they can be still to listen without distraction.
Barking can last for any length of time. Contact your veterinarian if your barking lasts more than four hours (lol, not really, though I might be calling up some foster homes by then). Barking can go on and on and on, all night and day, though thankfully that is very rare for most gliders. I’ve heard barking events that were just a single bark with no follow through. The typical barking event lasts around 20 minutes with variety in notes and beats.
Multiple gliders can bark at the same time. They do not do so as a call and response. Their barking does not share a rhythm or duration. The barks will weave in and out of sync reminiscent of your turn signal with the guy in front of you at a light. If one is interrupted, the other does not also stop. Moving them closer or further apart doesn’t affect much. Closing a door to cut off the sound will return about 20% of their attention to you.
Barking is the worst time to get a glider to willingly come to you, eat, play, chase feathers, or leave a pouch. Trying to show off how active and friendly a joey is to a potential buyer? Trying to coax them down from your ceiling fan? Trying to feather chase them to show off to a friend? This is not the time. Gliders are much less active, playful, and responsive while listening to a barking soliloquy.
Barking usually happens in the middle of the night, but can happen at any time of day or night.
Barking usually lasts about 20 minutes, but it can last any length of time.
Barking usually does not occur every night, but it can, or they may never bark.
Barking is usually interruptible, but not always. Turning on lights, offering treats, or otherwise distracting a barking glider may end or pause a barking soliloquy, I’d say it works about 70% of the time.
Barking is not usually triggered by an external event, but sometimes it is. I have seen them triggered into a barking event most often by something loudly falling in their cage. This barking always sounds a little faster and more insistent to me, but that might just be my heightened perceptions as I’m racing toward the cage room to see what fell.
People have all sorts of explanations for why their gliders bark. That’s fine, they are probably wrong though, or at least their theories are probably not generalizable to other gliders.
Gliders don’t want your attention when they bark, they would prefer not to be interrupted in their performance.
Gliders are not barking for food. They often refuse treats while barking, hold a treat until they finish barking, and have access to the exact same treats im offering them in their foraging cups when they start barking.
Gliders are not talking to humans. Other gliders have definitive and broadly shared reactions to the barking. This tells me they are definitely talking to other gliders not us.
Gliders are not scared when they bark (usually). Barking is in no way a sign of distress, stress, unhappiness, boredom, depression, fear, unbondedness, or any other negative psychological issues. Barking is not an informative symptom for any medical or behavioral issues. Barking is normal. Not barking is also normal.
So, Enjoy the song of their people each morning at 3 am, or invest in good headphones for sleeping in. Know that you can rest easy in bed, you do not need to run to them, in fact they would prefer it that way. Everything is fine, they are happy and performing for their real or imagined glider audience. I wonder if my gliders debate what it means when I sing in the shower?