Beardies in the wild. Where have they gone?

[Bluetongue1]

I think if people are taking something from the wild of course it will contribute to the decline.

While that that seems an obvious conclusion, it is not necessarily the case. Let’s use a simplified example to explain why… In the wild, beardies can live between 5 and 8 years. Clutch sizes vary from 10 to 20 eggs and they can have multiple clutches in one year. Therefore, it would not be unrealistic to expect a female to produce 5 clutches of an average of 15 eggs in her lifetime i.e. 75 eggs. Only two young out of 75 need to survive and reproduce in order to replace the parents. This will maintain a stable population. Or to put it another way, 73 young have to perish. Many will starve, others will be taken by predators, some will die of disease or parasites, others from trauma. So removing several offspring from this one reproducing pair will ultimately have no effect on the population size. It probably just means that less will starve as there will be more food to go around. In biological terms, this is known as a sustainable yield. If you were to remove 60 or 70 of the offspring from this one pair, then you might start to affect population numbers.

Bluetongues seem to have faired better than bearded dragons in surviving in the suburban environment, but even they are becoming scarcer now. Blueys don’t need trees and fallen timber to perch on and are happy with low vegetation in which to forage. Vegie patches always provided a good feed of leaves, flowers and fallen fruit. The ubiquitous European Garden Snail is a great protein meal for them, one that they quite obviously relish. From my observations the fallen fruit of wild blackberries was another favourite meal, providing food towards the end of summer and into autumn, when other sources were less common. Unfortunately, backyard vegie gardens went out of fashion and although there has ben a recent resurgence, they are mostly grown in raised beds these days. An active eradication campaign has also seen a marked reduction in wild blackberry patches in urban areas, being considered a noxious, thorny weed. What we called ‘tin’ sheds used to be common. They were actually made of corrugated iron and as the sheets rusted, they were replaced and the old sheets often stacked down the back or around the side, providing excellent shelter for blueys. These have now disappeared for the most part. The same with woodpiles in houses, which are now heated by gas or kerosene (so called ‘oil heaters’) or electric air con. Without shelter and a food source, no blueys.

Water Dragons are a really interesting case. I reckon they are very intelligent for a lizard, as their genus name would suggest. They quickly learn what poses a threat to them and what does not. Where they can, they will make use of house yards adjoining their habitat. For example, using a concrete or bitumen driveway for basking, yet moving off quickly if the garage door is opened or a car turns into the drive. They will remain on the opposite side of a fence if there is a dog that will chase them on the other side, or will enter a yard where the dog could care less about them. They do the same around people. They will also scavenge food scraps left behind by people. They seem content to occupy smaller territories where food from human sources is more plentiful than food in their natural habitats. If given access, they will colonize artificial waterways and water bodies. IMO, given the right conditions, these lizards are not just urban survivors but urban thrivers.
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Heres a very crap pic of a wild beardie down the road from me.

There is nothing crap about that photo. Crystal clear - great focus. Good job!

 

[james2109]

While that that seems an obvious conclusion, it is not necessarily the case. Let’s use a simplified example to explain why… In the wild, beardies can live between 5 and 8 years. Clutch sizes vary from 10 to 20 eggs and they can have multiple clutches in one year. Therefore, it would not be unrealistic to expect a female to produce 5 clutches of an average of 15 eggs in her lifetime i.e. 75 eggs. Only two young out of 75 need to survive and reproduce in order to replace the parents. This will maintain a stable population. Or to put it another way, 73 young have to perish. Many will starve, others will be taken by predators, some will die of disease or parasites, others from trauma. So removing several offspring from this one reproducing pair will ultimately have no effect on the population size. It probably just means that less will starve as there will be more food to go around. In biological terms, this is known as a sustainable yield. If you were to remove 60 or 70 of the offspring from this one pair, then you might start to affect population numbers.

Bluetongues seem to have faired better than bearded dragons in surviving in the suburban environment, but even they are becoming scarcer now. Blueys don’t need trees and fallen timber to perch on and are happy with low vegetation in which to forage. Vegie patches always provided a good feed of leaves, flowers and fallen fruit. The ubiquitous European Garden Snail is a great protein meal for them, one that they quite obviously relish. From my observations the fallen fruit of wild blackberries was another favourite meal, providing food towards the end of summer and into autumn, when other sources were less common. Unfortunately, backyard vegie gardens went out of fashion and although there has ben a recent resurgence, they are mostly grown in raised beds these days. An active eradication campaign has also seen a marked reduction in wild blackberry patches in urban areas, being considered a noxious, thorny weed. What we called ‘tin’ sheds used to be common. They were actually made of corrugated iron and as the sheets rusted, they were replaced and the old sheets often stacked down the back or around the side, providing excellent shelter for blueys. These have now disappeared for the most part. The same with woodpiles in houses, which are now heated by gas or kerosene (so called ‘oil heaters’) or electric air con. Without shelter and a food source, no blueys.

Water Dragons are a really interesting case. I reckon they are very intelligent for a lizard, as their genus name would suggest. They quickly learn what poses a threat to them and what does not. Where they can, they will make use of house yards adjoining their habitat. For example, using a concrete or bitumen driveway for basking, yet moving off quickly if the garage door is opened or a car turns into the drive. They will remain on the opposite side of a fence if there is a dog ? that will chase them on the other side, or will enter a yard where the dog could care less about them. They do the same around people. They will also scavenge food scraps left behind by people. They seem content to occupy smaller territories where food from human sources is more plentiful than food in their natural habitats. If given access, they will colonize artificial waterways and water bodies. IMO, given the right conditions, these lizards are not just urban survivors but urban thrivers.
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There is nothing crap about that photo. Crystal clear - great focus. Good job!

Thanks Blue Tongue for the thoughts and your conclusions. Whilst statistically you may be correct I believe that taking any wildlife from its natural environment for our own gain is completely wrong and can never be justified. Our world is in a vulnerable state when it comes to wildlife and we need to condemn any taking of reptiles. Kids need to see lizards and snakes in the wild. When I asked someone about viewing Koalas in the wild recently he said ah just go to the zoo. How sad- we need to be able to see reptiles and other wildlife in the wild for generations to come.

your right about water dragons. What a success story. Another example is the cane toads, what a shame they a such a pest as they are incredible survivors. We wish native wildlife could be so resilient. don’t underestimate the impact of cats too, especially wild cats. Yes they have always been around but are now closer to wildlife than ever before. In no they found a wild cat with over 20 geckos in its stomach from one nights hunt. Think of how much damage they can do to reptiles.

 

[Bluetongue1]

I was not condoning the illegal taking of any wildlife, just putting into perspective the effects of removing the odd individual from a given population. The real damage is done by loss of habitat and feral animals.

We often think of mining as a major player in habitat destruction, with some high-profile ecological disasters such as the Ok Tedi mine in PNG. On a global scale, mining pales into insignificance when you look at the effects of agriculture. Clearing of rainforests in SE Asia to plant oil palms and deforestation of the amazon rainforests for timber are two that are happening right now. What about in Australia?

Millions of hectares of wheat/sheep farmland were once covered with mallee, heath etc with an understory of native shrubs, herbs and grasses. Any fallen timber and rock is piled up into concentrated heaps and the timber was usually burned to get rid of it.

Forests used to be clear felled for timber or almost cleared and planted with pasture grasses for grazing. Cattle on cattle stations have hard hooves, and along with feral hooved animals, change the nature of our native grasslands. Then there’s the orchards and plantations for things like sugar cane and bananas, and so on. Add to that the urban sprawl and the damming of rivers to provide drinking and irrigation water and hydro-electricity.

Cats and foxes are the worst feral predators. It is estimated that feral cats alone account for nearly 2 million lizards per day Australia wide and even more birds. They also eat mammals up to their own body size. Goats will eat non-woody bark, often ring barking saplings, stopping these species from being able to reproduce in the wild. We have no hooved native animals. Hard hooved ferals break up the soil crust, leaving it open to erosion and even changing drainage patterns and vegetation regimes.

If it were not for collecting from the wild, we would not have any animals in captivity, be they pets or domesticated animals used in agriculture to produce food and other products. As for the koala comment, I think the guy had it right. I spent the most of my free time as a kid and youth out in the bush and I have only ever glimpsed two koalas in the wild. They were both really high up in tall eucalypts, barely visible and seemed curled up asleep. Had I not been involved in biological surveys where animals were trapped or netted, I would never have seen these animals close up, if at all. Yet a visit to the nocturnal house at the zoo allowed me to observe many of these critters behaving much more naturally than when working a trap line.

You said about being able to view animals in the wild. Unless you know what you are looking for, and where to look for it, you can spend a whole day in the bush and not see a single reptile. You have even less chance of seeing a native mammal. What you probably will see are some bird species and plenty of ants and flies. Australian zoos today, large and small, fixed and mobile, play an important role in bringing people and animals together. They are highly effective in educating people as to what is out there in our natural bushland and why we need to protect what remains of it. If you don’t have a lot of bush experience and do wish to see animals in the wild, then joining a naturalists club or a bushland protection society, or the like, is probably the best way to get to see native flora and fauna in the wild.

There is more I would like say but this is already a long post. It is good to be able share my perspectives with others. Thanks.

 

[james2109]

I asked Raymond Hoser aka the Snakeman about the decline of beardies and whether he hasd observed this too. This is part of his response ( quoted with his permission):
James,
Yes you are correct.
There has been a massive decline in beardies and Jackies (all species) in many areas (I have noticed this as well) and in some areas they persist well (or seem to be).
I do not believe disease is the issue, but more likely something is eating them (and probably young ones or the eggs).
Noting that beardies just lay their eggs in the open after digging a hole in soft dirt, things like foxes would easily find and eat them, but the fact they remain common in fox infested places, tells me that something else as well must be the problem.
The logical suspects would be something introduced (e.g. foxes) or perhaps some kind of bird. I do not suspect another species of reptile.
In some parts of Melbourne, feral water dragons are literally eating all the baby bluetongues and there is a marked switch in species as the water dragons expand.
The real issue is that you cannot keep doubling the number of humans in Australia every 40 years, moving species of critters all over the place and expect the ecosystems to hold up.
And in answer to the question how much has the pet trade impacted beardies
The impact of the pet trade on Beardies and most other reptiles is negligable. Other factors cause the decline and on a scale many orders of magnitude greater.
Plus when numbers of pets goes up, so too do the mutants and then no one even wants the "wild" type anymore.

 

[Herpetology]

hopefully its not this raymond hoser aka SNAKE MANNNNNNNNNNNNNNNNNNNNNNNNN

 

[Pythonguy1]

hopefully its not this raymond hoser aka SNAKE MANNNNNNNNNNNNNNNNNNNNNNNNN

View attachment 330714

That's (how do I say this) Interesting...

 

[james2109]

The one and only! He might be mad but he knows his stuff and he has been doing it a long time. He has written lots of amazing stuff about reptiles and hes been out there doing it.

 

[Rob]

His first book was one of the first herp books I got as a youngster of 16/17 years old, I still have it in pretty much mint condition. However, this "mad" side as has been said has resulted in the mere mention of him causing posts/threads to be deleted due to the unrest they tend to cause. While I'm happy to allow herp related discussion on him, please keep the circus theatrics discussion (like the photo posted above) on Facebook where it belongs.

EDIT: This was not directed at anyone in particular which is why I purposely didn't quote anyone, it was more just to put it out there that the usual Hoser bash-fest wouldn't be tolerated. I've since realised my original wording may have indicated otherwise so I have changed that accordingly.

 

[james2109]

No worries. I was simply interested in his thoughts on beardies in the wild and not the circus stuff as you put it. Thanks