In the comments of their poster entitled “Welcome to Grade THREE!”, the Battalion Bloggers asked some questions. Posts lead to questions and questions to a search for answers. Below is the next part of our shared learning journey as I attempt to find answers and learn more along the way.
For their original post…
For the related preceding post on this blog...
Hello Battalion Bloggers,
I know you're having are busy in school at this time and I have been very busy with DVD/CD work for schools and community groups so it seems it can take us some time to reply to each other but our contacts are always interesting.
I thought I would share some ideas I had when thinking about the questions and curiosities in your comment. I know some ideas I share can be a little hard to understand at times but this is what can make learning interesting as we try to discover meaning. To answer you, I always have to research more information, try to understand what I find and then try to explain what I find in in a way you can more easily understand. Our posts and comments means our learning journeys cross for a time. Here's what resulted...
We are glad that the perentie and lace monitors are only slightly venomous and that they are shy and will run away when they see people. Can the perentie and lace monitor venom kill a person if they bite them?
In the original post, I mentioned the monitors are thought to be slightly venemous but I haven't heard of any deaths from monitor bites in Australia. Some of the effects of a monitor bite from lace monitors or Komodos might be (according to Wikipedia's Komodo reference) rapid swelling, localized disruption of blood clotting, and shooting pains, with some symptoms lasting for several hours. The large Komodo has been known to attack and kill animals such as goats and there are reports of human deaths. As with all animals, we should be careful with the biting end and leave wild animals alone.
We wonder why the komodo dragon is only found in Indonesia now and not in Australia anymore?
Different species of monitor lizards are found in many countries. According to Wikipedia, they are found "through Africa, the Indian Subcontinent, to China, down Southeast Asia to Indonesia, the Philippines, New Guinea, Australia and islands of the Indian Ocean, and the South China Sea. A large concentration of monitor lizards occurs on Tioman Island in the Malaysian state of Pahang." What this suggests is there are many species of monitor lizards. The Komodo, perentie and lace monitors are just three.
HOW could they get to Indonesia when they once roamed Australia?
In my post, I mentioned fossils of Komodo dragons were found in Australia so they had once been here. If you look at the Komodo Dragon Evolutionary History link, it mentions recent fossil finds in Australia suggest it's possible Komodo dragons evolved in Australia and spread to Indonesia when sea levels were much lower during the last glacial period (around 12,000 to 110,000 years back). With the end of the glacial age, they were cut off from Australia by rising waters. Perhaps a changing environment wasn't suitable for them here in Australia so they died out leaving the Komodo only in Indonesia. We would need more information to be certain but, at this time, an accepted belief is the monitors evolved in Asia perhaps 40 million years back and then spread.
We also have evidence of much a much larger monitor lizard in Australia known as Megalania (Megalania prisca or Varanus priscus). It is thought to have died out 30,000 to 40,000 years back so it's possible the earliest indigenous Australians had seen them. Most recent estimates say they might have grown to 4.5m (15 feet) and weighed up to 331kg (730lb). With the largest wild Komodo measuring 3.13 m (10.3 ft) long and weighing 166 kg (366 lb), the megalania would have been huge. I wouldn't go hiking in our national parks if they were still around.
We wonder if they lived in both places but then they died out in Australia.
I liked your suggestion and suspect there was a time when they were found in both places. Somewhere back in time monitors must have had a common ancestor. The different species evolved when populations were cut off from others. Adapting to the local conditions, in time they developed differences to other populations. When there is enough change so one population is unlikely to breed with another*, they are said to be a new species. Look at the monitor lizard below. It is a varanus salvatorii (Salvatori's monitor) from New Guinea.
Do you notice all of the monitor lizards on this post have similarities? They are all part of the genus varanus (monitor lizards).
Do you see they also all have differences? The differences suggest different species.
* There are examples where animals of different species can interbreed (have babies together) so long as the animals are of the same genus.
horse (equus ferus) + donkey (equus tigris)= mule
(equus is the genus and ferus/tigris are the species names)
male tiger (panthera tigris) + lioness (panthera leo) = tigon
male lion (panthera leo) + female tiger (panthera tigris) = liger
(panthera is the genus and tigris/leo are the species names)
Why would they die out?
As mentioned above. the Komodo dragons may have died out in Australia because of climate change. As an example, when the first people came to Australia perhaps fifty to sixty thousand years ago, Australia was much wetter with forests and lakes. In time, changes in climate led to Australia drying out leaving desert where once there was forest. There might have been other reasons why they became extinct in Australia but, without evidence, we're only guessing.
Spike is SO cute! We think that the picture of the echidna digging his claws into the grown and curling into a ball to protect himself was SO cute! Do echidnas get frightened easily?
When I discovered an echidna in my garden, it was probing the soils with its snout in search of food. It didn't take much notice of me and I suspect their eyesight isn't too strong. When I came too close, it dug its claws into the ground and showed its spines. I don't think they are too easily frightened but, just like you, they are careful if danger is near.
Once they feel danger has gone, they go back to their hunt for food.
We wonder if they do much damage to gardens like voles can do?
If I hadn't seen the echidna in my garden, I don't think I would have known it had been there as they leave little trace. It's possible others have been in my garden but I have only ever seen one. I have seen many in the wild. I saw the above echidna waddling its way across a local park. Even though I was close, it either didn't see me or wasn't frightened.
We wonder what they like to eat … besides ants!
In the wild, the echidnas mostly eat ants and termites. The above photo shows a local termite mound around 1m high although I have seen some termite mounds much higher in other parts of Australia. When hiking, I sometimes see termite mounds where I can tell echidnas have been using their strong claws to dig. Once opened, the echidna can use its long, sticky tongue to catch ants or termites.
My favourite local animal sanctuary, Potoroo Palace , has three echidna. It isn't possible to gather enough ants or termites for them so the keepers mix a special recipe to feed their echidna. The mix includes minced meat, olive oil, raw egg, glucose powder, baby porridge, processed bran, vitamin E powder and calcium powder. In the video below, you will see Spike enjoying a meal as the keeper shares information with tourists.
Schools and students have permission to use this video clip for non-commercial, educational purposes.