Monday, February 04, 2008

Western Bearded Dragon, Pogona minor minor



A lizard from the old world family Agamidae.

Agamidae are part of the infraorder Iguania, which is the very first branch of the lizard evolutionary tree, making them amongst the most primitive of lizards and are thought to represent the eastern Gondwana relative of the Iguania. Although amidst debate, these ancestral lizards are reasoned to have arisen in the South American continent and spread via Antarctica to the Indian subcontinent and Australia, both of which contain the largest number of endemic species.

The Australian agamid clades are concentrated in the more arid regions of Western, Northern and Central Australia with fewer species in the wetter and more heavily forested areas of Eastern Australia. This probably reflects the breaking up of Gondwana and the retreat of the forests as Australia dried whilst drifting north. It is during this period that agamids in Australia began to diversify and become more common in the fossil record. Pogona was one of these lizards!

Western Bearded Dragon, Pogona minor minor

The Western Bearded Dragon, Pogona minor minor is often simply referred to as Pogona minor (the second minor referring to its subspecies status) as it occupies most of WA, except for the northern region, the Nullarbor and the SW corner. Another subspecies, Pogona minor minima or the Abrolhos Bearded Dragon, only occupies the Houtman Abrolhos Islands. A third subspecies Pogona minor mitchelli is found in the far northern near coastal portion of WA.

Pogona minor is not a particularly large lizard, growing to a little over 15" (38 cm) in length including the tail, but going on its distribution it is obviously a very successful species and besides occupying a very large portion of WA, also extends into the western half of SA and the lower SW of the Northern Territory. The Eastern Bearded Dragon (a similar looking lizard from eastern Australia) abuts in the coastal Adelaide region. This eastern species, Pogona barbata, is a little larger than its western counterpart and differs by having several rows of large spines along its flanks, whereas the western bearded dragon has only one.

A mating pair of Western Bearded Dragons

All dragon lizards are egg layers and are often seen digging a nesting chamber where up to 12 eggs are deposited, after which the connecting tunnel is filled in. This activity can take several days and is often thought that she has abandoned the nest, but more often she is busy inside, evidenced by the opening being in-filled a day or two later. In good seasons the western bearded dragon can produce two or more clutches, making this nesting operation quite common and often observed.


Pogona minor digging the nesting chamber, and not impressed by my interest.
Hidden at last!


These lizards have a reputation of being lovers of the sun, preferring the more open arid regions and often seen sunbaking. But this is not quite correct as they require a narrow temperature range and when this is exceeded (as is often the case during summer), they seek shelter and are considerably less active. Dragon lizards are commonly seen perched on posts and other elevated positions during spring and early summer, this not only provides them with sunbaking opportunities, but a means to survey and maintain their breeding territory. They are also often seen sunbaking in autumn, but are seldom encountered during summer and then usually only early in the morning.


A disturbed sunbaking western bearded dragon reviewing the potential threat.


Pogona eat a variety of foods including vegetable matter like flowers and even seed, although insects and other invertebrates would make up the bulk of their diet, however the odd small, slow moving mammal would not be ignored.

Typical dragon surveying its territory for rivals, mates, predators and prey.

Western Bearded Dragon, Pogona minor minor


Dragon lizards are well known for their visual method of communication where head bobbing, leg and body lifting are commonly practised. Apparently each dragon species has its own procedures, but all aim to discourage other males or to attract a mate, but the most dramatic display is used in defence to deter a potential predator. Here the lizard will flatten its body which is turned towards the threat to make it appear bigger, the frill is fully extended with all spikes projecting away from the body and the mouth wide open to show a colorful interior. All bluff of course, but still very effective.

A well camouflaged western bearded dragon keeping a lookout from a dead tree trunk.


Unlike most skinks and geckos, dragon lizards do not shed their tails to escape from predators, but can run very fast with a sudden turn of speed, some even running bipedally like a crazed clown, plus they are very good at climbing, so probably suffer less predation. However unlike the blue-tongue lizards, they are nowhere near as common in the big cities unless there are large open spaces so they can keep an eye on their territory and use their speed to avoid predators.


All kids are cute, as it this young Pogona minor frolicking amongst the Trigger Plant flowers.centre


Australia is a land of reptiles, particularly in the more arid areas with unreliable rainfall and consequential irregular food supply; it nevertheless suits perfectly the biological make up of reptiles. Their more energy saving lifestyles, along with their lower requirements of food and water allow them to take advantage of the good times, whilst also surviving well the bad. So when you next look at a reptile, don't think of them as being primitive, but supremely well adapted. They were here long before we came onto the scene and will probably be around long after we depart. Many think reptiles are dumb, but this is certainly not the case, they have very good memories and some are very social, but the most striking thing about them is how accommodating they are if they live near you. Providing you don't threaten or interfere, most will treat you with great respect and will be no trouble at all. We should make room for more reptiles in our lives, for not only are they interesting and entertaining, but generally will eat the things we don't like. So get eco-friendly, help reptiles to help you!


9 comments:

Gaye from the Hunter said...

What an attractive lizard the Western Bearded Dragon is. I hope on my next visit to WA I can find one.

Have you observed the flaring of the beard when you have approached? My resident Eastern Bearded Dragon is a joy to have in the garden, as you rightly comment that all lizards are.

Your lizards appear to be beautifuly patterned. I have noticed that young Eastern Bearded Dragons have a nice pattern running down the back, but larger lizards are more evenly coloured.

A very enjoyable account of your dragons, and fabulous images.

Cheers
Gaye

Esperance Blog said...

Hi Gaye
I haven't see my dragons flaring their beards, possibly as they are not acknowledging my presence (don't know them individually as well as you do yours), nor am I being aggressive to make them react. With me they either stay still or scamper away.

Re marking intensity. The males and young are quite bright, but the females seem to lose color as they mature (check the one digging the nest).

Thanks for your comments.

Regards
Jack.

Anne-Marie said...

Lovely account and beautiful photos, Jack! Most enjoyable. :) I have a Canon A85 and like yours, I think they take very good photos for our needs! Cheers, Anne-Marie (froglover from GE forum)

Esperance Blog said...

Many thanks Anne-Marie, those little PowerShot Canon cameras are great aren't they? Having fewer pixels just means you have got to get a little closer. I've been thinking of getting another but with a larger lens, but so far nothing has twisted my arm to do so. Another advantage in procrastination is they are getting cheaper by the month. :)

Jack

Purpleflowerpatch said...

Hi Jack - I love that these shots are from Esperance! We have only lived here for 7 months and my daughter is a keen nature photographer so we appreciate your snaps.
This is such a lovely area for nature studies.

Nice to 'meet' you!
Jenny

Esperance Blog said...

Hi Jenny, nice to meet you too and welcome to Esperance. As you say the Esperance region is very interesting for nature lovers. It is a harsh environment but its biota well adapted to it.

I personally like this region as it is so remote from major populated areas and you can still come across places that have not been visited since the original aboriginal owners left them.

You have probably noticed that this time of year most wildlife and certainly most flora is dormant, or lying low until we get our first good rain of the year. This tends to occur around Easter and I am impatiently waiting for it, so the bush will once again come to life.

Hope to meet up sometime,

Regards
Jack.

Matthew Onan said...

G'day from up in Geraldton Jack! I stumbled upon your blog a few months ago and remembering being very impressed by it (and indeed wanting to be well-versed enough in wildlife to start up a similar blog myself!), and I'm very glad to have found my way back here after looking up information on the Western Bearded Dragon! You must have seen this dragon around a fair bit to have so many different photos of them as you do; I've had a few sightings myself, 4 to be specific. Almost makes me think that pogona minor minor being listed as a species that is 'rare or likely to go extinct' might be something of a dramatic conclusion on the matter. As somebody who's into photographing and learning about wildlife myself, I know that I would have been hugely pleased if I found, observed and photographed a pair of dragons mating, or a female dragon digging out her burrow - great work on these shots, they make for what I think of as quite 'valuable' viewing material, valuable in terms of observing and photographically showcasing something that most of us might not otherwise get to see and learn from. Your observations and information on here are great too, I'm going to try and apply some of your findings and knowledges to my own herping and birdwatching trips in future :)

By the way, I stumbled across this page after making my fourth sighting of this lizard today; it (I soon found good reason to speculate that it was a female) was sitting in the middle of a lightly trafficked country road, basking in the sun at about 1.10 or so in the afternoon. Thankfully I was driving very slow (most people along these roads rip along at at least 110k - I think I was doing about 60) and thus had plenty of time to suss out what was on the road. I stopped the car, jumped out of it and picked the lizard up - I'm always baffled at this, why dragons just sit there, calm as anything, and let you pick them up! At first glance, I noticed it looked very fat in my hand, yet at second glance I saw that there were 2 relatively pronounced semi-circular bulges coming from both her sides, of a size slightly smaller than a marble. I didn't want to touch them, thinking that they very probably must have been eggs inside of the lizard - what else could they have been, four particularly large meals that just so happened to bulge symmetrically from either side of the lizard? Anyhow, I placed her at the side of the road, and stamped my feet about a bit to make her run off into the bush - here's to hoping that she doesn't go back out to bask on the road to bask anytime soon, at least until she's laid her eggs... after all, if they really are 'in danger of becoming extinct' then every clutch of eggs matters!

Anyhow, you've got a really tremendous blog going on here - keep up the great work, you've got a fan in me!

WA said...

Hi Matthew, thank you for your post. An interest in nature is a lifetime activity, always with new things to see and an endless stream of information to engage ones mind.

You mention that the Western Bearded Dragon is rare and likely to go extinct, however I am pleased to say this is not the case. It is quite common and widespread, although cats and foxes prey heavily upon them and in some areas because of this predation they are rarely encountered.

Juraac Scribe said...

Hey, I was just reading this and I'd like to thank you first off for providing pictures. I had been looking around for information on these little blessings when I came across an obviously inexperianced Reptile owner who told me that the Western Bearded Dragons are the only ones that look like babies (In reference to their head Shape) through out their entier life. I thought that this was obviously untrue and seeked images, google results were untrust worthy for I haven't seen them before, so I turned to information packed sites on the western beardies. This site provided what I needed, so thank you. As well I had recently gotten one of these guys as a pet, (Licenced of course.) and he's a little cutie. He is young, so I still had to seek pictures to prove my point. As I looked over the pictures I found A LOT of information that is never listed in Beardie Care Sheets that really entertained me. Thank you for the good read. I also have one thing I was hoping you could help me with, it involves my bearded dragon. Please email me at 'Bleedingscribe@hotmail.com' if you have time to help me out. It's nothing big, just a question that you might be able to help me with, (Email is required because I need to send you pictures if you're up for it.)

Sorry for the long post. I need to stop spilling out my life stories.