Life Span and Size
In the wild, Bearded Dragons live an average of 3-5 years. In captivity, this time is lengthened to 7-10 years, although it is thought that they can live longer as more advanced ways of taking care of them are put into practice more often. They reach their adult growth by a year and a half. Bearded Dragons can be broken down into 4 age groups. Hatchlings is from 0-2 months, Juvenile is from 2 months to 7 months, Sub-Adult is from 7 months to 18 months, and Adult is 18 months on. In the wild, the average adult size is 24 inches, in captivity it is 18-22 inches, with 24 inches being relatively rare. This difference in size between the captive and wild Bearded Dragon population is largely because of excessive inbreeding rather than purposely trying to make them smaller, and also tends to come hand in hand with the fact that captive bred Bearded Dragons are generally much more fragile health-wise than their wild counterparts.
a) Femoral pores. This is on the left picture. While both sexes have these, the male has much larger ones. The picture shows a male.
b) bumps around the vent area. One bump is female, two bumps are male.
Bearded Dragon Body Language
For a short time during the spring mating season in the wild (Bearded Dragons only have a mating season in the wild, not in captivity) the normally territorial and solitary Bearded Dragons form small colonies. This is where they have probably developed one of their most fascinating features; their body language. Bearded Dragons get their names from the flap of spikey skin under their chin, that they can inflate to dominate, frighten, or defend. Bearded Drgaons will also bob their heads to show dominance. And they slowly wave, almost as if saying goodbye, to show submissiveness and willingness to mate. They also can blacken their Beard completely to show distress, aggression, or prior to mating. When feeling defensive or aggressive, they will flatten their bodies, gape their mouths, hiss, and sometimes inflate their beards as well. They can change their entire body coloring to be lighter or darker in accordance to mood and temperature, but the color changes are not anywhere in the realm of what a Chameleon can do.
Video: example of 2 Beardies (captive), one arm-waving and one head-bobbing. Video made by joftherings.
First, keep in mind the above signs of a defensive Bearded Dragon. Bearded Dragons do not generally bite out of malice, but out of fear. You are, after all, very large and predator-like. If a Beardie is showing the signs of defense, he is likely terrified, and should not be pressed. If they are pressed, they could bite. When handling a Beardie like this, there are several things that you can do.
First, slowly put your hand in the far side of the cage. Just leave it there, without approaching. Do this several times a day. After a while, you can gradually move your hands closer to the Bearded Dragon. Second, every time your Beardie tries to bite, shove his favorite green/veggie/fruit (cut into small sizes, of course, you don't want to choke him) into his mouth. This will let him see you as a friendly source of food rather than a predator. There is a very specific way of picking up a Bearded Dragon as well. You want to go from the side or below, never from the top, as your hand approaches him. Then, gently scoop him up from the bottom, making sure to support his stomach, all 4 legs, and as much of the tail as possible. If he feels unbalanced, he will flail, and that is what supporting all of him prevents. A Beardie can easily scratch a human badly when he is flailing. One of the best handling tricks is called the "Shirt Trick". This involves waiting until your Beardie is really sleepy, then wrapping him up in a shirt that smells like you to rest. This will get him used to your scent. After a while, you can pick him up in the shirt and let him fall asleep on you. This is a great trust builder.
If you are patient and kind, and keep in mind these tricks, you should have a friendly Beardie in no time.
More than 3/4 of reptiles carry Salmonella. Salmonella in reptiles is contained in the digestive tract, and exits their body with their feces. Touching a reptile's feces, even trace amounts, and then ingesting it can pass the Salmonella on to humans. While usually an unpleasant but not serious illness, the old, the young, and the immune deficient can die from Salmonella. However, there are ways to prevent infection.
First, always wash your hands with an antibacterial soap after touching the lizard and/or his enclosure. Secondly, keep the reptile away from kitchens and dining rooms where food is prepared or eaten.
Thirdly, dispose of lizard feces in the toilet or trash can, not the sink or bathtub. Also, do not bathe the lizard in the same place where you will bathe an infant or young child.
With care, transmission of Salmonella from reptile to human can be avoided.
A Bearded Dragon's Senses and Anatomy
A Bearded Dragon's scales are rough and bumpy for a reason. When it rains, the bumpy spots help collect water between them. A Bearded Dragon will then bend downward, and all of the water will flow between the bumps to its mouth, where it can be licked up.
When the Bearded Dragon becomes distressed or aggressive, their normally soft and rubbery spikes can abruptly become prickly. They have a lot of control over their spikes, and they know to use it to hurt others who have senses of touch. They also have exceptional control over their limbs, they can lock them in place so that they can sleep standing up and other such feats.
Taste and Smell
Another unique sense that they have has to do with the parietal/third eye. I don't mean anything psychic here, of course. The parietal eye is located at the top of their heads, and you can see this as an oddly colored scale in the center of the top of their heads. What this does is sense heat and shadows, and possibly light. In the wild, this serves as a warning if one of their main predators, birds, are swooping down at them. It is also possible it helps them to bask.
Brumation is basically hibernation-lite. It occurs is some dragons that are a year of age or older, although it does not occur in every Bearded Dragon. Brumation can happen at any season of year, but the vast majority of the time it happens in the winter of whatever place you are in. Every Bearded Dragon brumates differently. Some just slow down for a few months, some slow down and stop eating, some take long naps, and some sleep for months at a time without break. Its also possible for a Bearded Dragon's brumation habits to change as it gets older.
During a typical brumation, your Bearded Dragon should not lose any weight to speak of.
They should get a vet check just prior to brumation, when they are showing the first signs of lethargy, and the vet appointment should include a fecal check.
You should provide your Bearded Dragon with a hide of some sort on the cool side of the habitat in which he can rest. Temperatures can safely fall into the low sixties during brumation. If your Beardie wakes up briefly offer water and food. They may not take the food, that's normal. If they do eat, encourage them to have a bowel movement before they fall back to sleep, otherwise the food may rot in the stomach. Bearded Dragons have an instinct about this, and probably will not fall deeply asleep while still carrying lots of food in their stomach.
In a few weeks to a few months, depending on the Bearded Dragon, normal activity should be resumed.
Bearded Dragons in the Wild
Bearded Dragons in the wild will eat any plants they can get their teeth around, insects, and if they can catch them small rodents and small lizards. Bearded Dragons will spend a large part of their day climbing up on something and sitting in the sun. When it is cold at night or during the winter, they will burrow underground and sleep to maintain their temperature. They will do the same thing if it gets too hot for them. In winter, they go into something called brumation, which is similar to hibernation. They are only around each other in groups during mating. After they mate, the group will split (they aren't social for the majority of the year, which is why there are problems keeping them together in one enclosure long term). That single mating will give the female multiple groups of eggs, and she will only mate once a year since she retains sperm. They don't form permanent partnerships. The female will go somewhere to lay her eggs after leaving the group, then she will bury them and abandon the site. Once the eggs hatch, the vast majority will never reach adulthood. They have many predators, from birds to dingos to cars.
Below are two maps, the orange and white one shows the distribution of Pogona vitticeps within Australia and the multicolored one shows the type of land in Australia, so you can get an idea of their habitat. Bearded Dragons are only naturally found in Australia.