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DISPLAYING POSTS TAGGED: mmdc (25)

Nature's nappies

Author
by Alice
Publish date
14 November 2013
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Comments (1)

Here at the Melbourne Museum Discovery Centre we are inundated with a wide variety of interesting enquiries. We recently received this stunning photograph from a keen bird enthusiast in Camberwell, wondering what was being fed to the young chicks.

Wattlebird with faecal sac. Wattlebird with faecal sac.
Image: Jim Love
Source: Jim Love
 

Interestingly, the parent wattlebird pictured is not actually feeding this infant but cleaning up after it. 

The black and white material in the parent’s beak is what is called a faecal sac, a mucous membrane that contains the excrement and uric acid (the bird equivalent of urine) of the young nestling. The thick membranous exterior of the sac is strong enough for the parent to pick up with their sharp beak to carry away and dispose of without puncturing it. They are just like a disposable nappy for birds!

Faecal sacs are usually excreted by the chicks shortly after feeding takes place, but this varies from species to species. In the case of the wattlebird the production of a faecal sac is almost instantaneous after feeding. This immediate reaction ensures that whichever parent feeds the chicks, will also be there to carry away the waste at the same time. You can see this occurring in the image below, where the parent is extracting the sac from the nestling’s cloaca as it is being produced.

Wattlebird with faecal sac. Wattlebird with faecal sac.
Image: Jim Love
Source: Jim Love
 

Parents remove faecal sacs from the nest for a number of very important reasons.  Not only do they allow the nest to remain clean and hygienic for the young nestlings, but their removal also deflects the attention of predators by eliminating the scent and sight of the faecal matter. Different species dispose of their faecal sacs in different ways, some preferring to drop them into bodies of water to completely erase their scent while others simply drop them nearby.

Some species of birds will even eat the contents of their baby’s faecal sacs for the first couple of days after hatching. In very young nestlings the bacteria required to digest their food are still under development, hence their excrement is rich in partially digested food. This allows the parents to feed more worms and insects to their young as they can substitute their own meals for the nutrients in their baby’s droppings. 

Wattlebird with faecal sac. Wattlebird with faecal sac.
Image: Jim Love
Source: Jim Love
 

Not all species of birds produce faecal sacs. Young water birds such as ducklings and goslings leave their nests as soon as they hatch, often never returning, and therefore do not have to worry about continual housekeeping. While other birds including eagles, herons and some sea bird species that nest high in trees and on cliffs, will simply back up to the verge of their nests and excrete off the edge.

I will leave it to you to decide whether you think faecal sacs are disgusting, strange or just plain fascinating. Personally, I wish that all human babies were this easy to clean up after!

Fossilised Champignons

Author
by Siobhan
Publish date
15 September 2013
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Comments (1)

Remember The X-Files? If you were a fan, you fell into one of two camps – you either liked the mythology arcs, or the Monster-of-the-Week episodes. I fell firmly into the latter camp. I liked one-off weirdness, lacking the attention span for conspiracy narratives. It is in this spirit that I present to you a short episode of "What on earth is THAT?!" from the Discovery Centre.

At the beginning of winter this year, a woman came into the Melbourne centre with some "mysterious objects". We get a lot of mystery items here, and they are normally fairly easy to identify – pieces of manufacturing slag, cicada cases, random pieces of urban archaeology that work their way up from old rubbish pits.

As she removed them from her bag, she said, "they look like fossilised champignons." An odd description, but entirely accurate. The items she unwrapped did indeed look like small mushrooms. They weren't fossils, as they were obviously made of a chalky substance; soft enough to flake and leave a slight powdery residue on one's fingertips. Our visitor said she had discovered them in the mud on the shores of a freshwater pond on Kangaroo Island, and mentioned, in an offhand manner, that they were amongst some crayfish carcasses, and perhaps they had something to do with local platypus? I was stumped. My colleague Wayne, a chap with a palaeontological background, was equally stumped.

Crayfish gastroliths Crayfish gastroliths, brought in to the Discovery Centre for identification.
Image: Siobhan Motherway
Source: Museum Victoria
 

Found in platypus territory, and made of chalky material? We did some preliminary research: were they dehydrated platypus eggs? Some weird botanical thing? A fungus? Yes, I did google "fossilised champignons". Getting nowhere, we turned to our various departmental experts in Mammalogy, Marine Invertebrates and Geosciences; even our pet Entomologist. No luck.

On the off-chance that our Live Exhibits manager had seen something similar on fieldwork, I emailed through the photographs to him, and he shared them round the office. Victory! Gentleman-and-scholar Adam Elliot knew immediately what they were. It turned out that our enquirer's by-the-by remark about the crayfish was the salient information – these "fossilised champignons" are freshwater crayfish gastroliths. When preparing to shed, the crayfish forms these stones to store the calcium they will need to help form their new exoskeleton. After they've shed (a process called ecdysis – remember that one for word games), they reabsorb this calcium to help create their new shell. These particular examples are very, very large.

Crayfish gastroliths Crayfish gastroliths, brought into the Discovery Centre for identification.
Image: Wayne Gerdtz
Source: Museum Victoria
 

This blog post from the WA Museum gives a great rundown on how the process works, and includes a photo of some smaller gastroliths from a similar identification request.

So there you have it, mystery solved. We'll keep an eye out for more oddities – I've always liked them best.

Drawing class in the Discovery Centre

Author
by Max
Publish date
5 September 2013
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We recently had a request from Debbie Mourtzios, a teacher at Box Hill Institute, to hold a drawing class for Graphic Design students at the Discovery Centre using natural science specimens.

Discovery Centre Drawing class Discovery Centre Drawing class
Image: Debbie Mourtzios
Source: Debbie Mourtzios
 

As the theme of the class was texture, Debbie asked if we could supply examples of fur, feathers, scales, claws, wings, or anything that can illustrate textures.

  Discovery Centre Drawing class Discovery Centre Drawing class
Image: Debbie Mourtzios
Source: Debbie Mourtzios
 

We contacted our Vertebrates Collection Manager who gladly loaned us specimens from the Mammal, Bird and Herpetology collections. We also used specimens in the DC’s interpretive collection. We had bird wings, an echidna, a glass sponge skeleton, a bird of paradise, various bones, reptiles, shark egg cases, all on tables in the Seminar Room, plus all the interpretive collection objects in the Discovery Centre itself. They were not wont for variety.

  Discovery Centre Drawing class Discovery Centre Drawing class
Image: Max Strating
Source: Museum Victoria
 

The eighteen students spent two hours drawing the various specimens. It was very rewarding to watch the students using the centre and its resources; it was also unusually quiet for such a large group. I guess that’s what focused attention sounds like.

Discovery Centre Drawing class Discovery Centre Drawing class
Image: Debbie Mourtzios
Source: Debbie Mourtzios
 

Links

Victoria & Albert Museum

Greek journeys at Bonegilla Heritage Park

Author
by Alex
Publish date
1 September 2013
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Alex Dellios, one of our Immigration Museum volunteers, recently re-visited Bonegilla as part of her ongoing research for her thesis 'Bonegilla Migrant Camp: Constructing Public History, Negotiating Collective Memories' at the University of Melbourne.

Bonegilla Heritage Park's newest exhibition From Petronis and Ekaterina to Peter and Catherine: Greek Journeys Through Bonegilla touches on more than just the Bonegilla experience of Greek migrants—it subtly explores issues of Greek migrant identity and adjustment in post-war Australia. Open since December 2011, but neglected by this researcher until now, this exhibit is small but surprising. A combination of images, text and objects fill one of the larger rooms in one of Block 19's huts. Information is offered (in both Greek and English) on themes like 'The Greek Farmers Project', 'Building a Greek Community', and 'Sponsorship vs Assisted Migrant Scheme'.

From Petronis and Ekaterina to Peter and Catherine: Greek Journeys Through Bonegilla From Petronis and Ekaterina to Peter and Catherine: Greek Journeys Through Bonegilla
Image: Alex Dellios
Source: Museum Victoria
 

Uniquely, the exhibition does not shy away from an exploration of the scheme and government policy that shaped post-war migrants' settlement experiences. The personalised voice is provided through the testimony of migrants themselves—short and snappy quotes appear on blocks throughout the room. The objects alone seem incongruous, items that often come to mind when building Greek stereotypes in Australia: namely, the bouzouki. Other items also appear behind glass cabinets, presumably donated by Greeks ex-residents.

From Petronis and Ekaterina to Peter and Catherine: Greek Journeys Through Bonegilla From Petronis and Ekaterina to Peter and Catherine: Greek Journeys Through Bonegilla
Image: Alex Dellios
Source: Museum Victoria
 

The second, smaller room contains an unexpected gem—a collection of remarkable miniatures by Tasos Kolokotronis of his village in northern Greece. All of them are created from his memory. They're very detailed miniatures, of village houses, a church, a school, and even the White Tower of Thessaloniki.

From Petronis and Ekaterina to Peter and Catherine: Greek Journeys Through Bonegilla From Petronis and Ekaterina to Peter and Catherine: Greek Journeys Through Bonegilla
Image: Alex Dellios
Source: Museum Victoria
 

Overall, Bonegilla's newest addition is small but enjoyable exhibition that cleverly explores the story of Greek post-war migration. And it appears at a site for which the Melbourne Greek community, especially through the Bonegilla Ex-Residents Association, have displayed unparalleled fondness.

The exhibition, like the rest of the Heritage Park is free and open seven days a week.

Links

Bonegilla Migrant Experience

The Bonegilla Story

Destination Australia

Coins and medals

Author
by Jo
Publish date
6 January 2013
Comments
Comments (1)

Your question: Where can I find out more about the coins and medals I have?

We often in the Discovery Centre receive enquiries about coins and medals. Our Collections Online website provides information about many of the coins, medals and trade tokens in the collection. We currently have approximately 7500 coins online, 2800 medals online and 2800 trade tokens online!

Coin, Holey Dollar, New South Wales, 1813 The obverse of the host coin and featured a laureate bust of Charles III (mostly removed with the central dump) facing right. At the bottom of the overstrike is a spray of olive leaves with the artist's initial H at its centre.
Image: Naomi Andrzejeski
Source: Museum Victoria
 

Melbourne Museum Discovery Centre

You can come into the Discovery Centre and make use of the library resources from 10am until 4.30pm, Tuesday to Saturday. You can also come in and look at the coins and medals we have on display in our reference drawers, featuring medals from the International Exhibitions held at the Royal Exhibition Building in 1880 and 1888.

Florin, 1947 Silver coin - Florin (Two shillings), 1947
Image: Unknown photographer
Source: Museum Victoria
 

Australian Coins and Medals

The Numismatics Association of Australia provides links to many relevant websites, and has also published online the past issues of its Journal, which has many articles of interest on the history of Australian coins and medals. See also the website of the Numismatics Association of Victoria for its activities and journal.

The National Museum of Australia features convict tokens and agricultural medals on their website.

Reserve Bank of Australia’s Museum of Australian Currency Notes provides a timeline of Australian paper money and educational resources.

The ANZ Banking Museum also provides information about Australian currency, the museum tells the story of Australia's banking heritage through displays of items such as banknotes and coins, moneyboxes, office machines, firearms, gold-mining equipment and uniforms.

Australian Penny, 1920 Penny coin from Australia 1920 (Kookaburra side)
Image: Jon Augier
Source: Museum Victoria
 

Useful publications include:

Leslie Carlisle Australian historical medals, 1788-1988 (2008) available in the Melbourne Museum Discovery Centre.

World Coins and Medals

The British Museum’s Department of Coins and Medals provides a guide to books, web resources and associations. The site covers not just British coins and medals, but Roman, Greek, Oriental and modern coins, tokens, medals and paper money.

The Royal Numismatics Society (UK) has a web page of links to relevant web resources.

1930 Penny, proof coin 1930 Penny, proof coin
Image: Jon Augier
Source: Museum Victoria
 

Useful publications include:

Standard Catalog of World Coins, published by Krause Publications. There are separate volumes now published for each century from the seventeenth century to the present.

And see the detailed book list at http://www.britishmuseum.org/about_us/departments/coins_and_medals/reading_list.asp

Got a question? Ask us!

The Adventures of Ally, the albino Possum

Author
by Max
Publish date
21 November 2012
Comments
Comments (10)

One of the many questions we are asked in the Discovery Centre is about the many and varied birds and mammals people sight in their own surburban backyards.  One such enquiry came to us from Steve from East Brighton who had spotted an albino possum in his garden.

Ally, the albino possum Ally, the albino possum
Image: Steve Mitchelmore
Source: Steve Mitchelmore
 

In February 2012 Steve discovered an albino baby brush-tail possum in his backyard. He wanted to know how rare they were as he had been observing possums for years, and this is the first albino one he had seen. One of our experts responded with the following;

Albino mammals are not totally unknown; we have received specimens at about a three year interval on average. Once the gene is introduced into a local population then their occurrence becomes a bit more periodic although only about once in a generation. Because they are not camouflaged as well as their parents or siblings they are readily detected by predators and could be easily taken as prey. A true albino will also have poor eyesight due to the lack of pigmentation in the eye again making them susceptible to predation. It will be interesting to follow this young animal and see how it survives such traumas.

Ally, the albino possum Ally, the albino possum
Image: Steve Mitchelmore
Source: Steve Mitchelmore
 

To which Steve responded;

About three weeks ago I noticed the small tail and one paw protruding from the mother's pouch seemed unnaturally pale in colour, then last night the juvenile, creamy white with deep red eyes, was on its mother's back...

P.S. Regarding predators, do you know if Powerful Owls inhabit the East Brighton area?

To which our expert replied;

I am unsure about the Powerful Owl’s situation in East Brighton but I can say that they have been seen/heard in many Melbourne suburbs. So if the area concerned is heavily vegetated – that is with large trees then there is every possibility that one of these large owls will make its presence felt.

Early in July, Steve sent the following update;

... you mentioned that it would be interesting to follow her development and any 'traumas' she may endure.  She still comes by almost every night, having been AWOL on only six or seven occasions since late January.  She has the un-original name of 'Ally' (as in Ally the Albino)...  As for traumas, so far so good, apart from when she fell into the pool three nights ago.  Luckily the water level was so high following all the recent rain that she had no trouble getting herself out. 

Ally, the albino possum Ally, the albino possum
Image: Steve Mitchelmore
Source: Steve Mitchelmore
 

Then in late July, he sent in his last update;

Hate to be the bearer of bad news, but . . . Sadly, Ally has not been sighted since Monday night...Some months ago she disappeared for three nights straight, but I won't hold my breath after seven.  I've made numerous calls to local vets, DSE, Wildlife Victoria...Animal Rescue etc. all to no avail and searches of neighbouring yards for fur or remains have also been fruitless... I'm still amazed she survived as long as she did.  Anyway, it was certainly an enjoyable (and educational!) six months.  She will be sadly missed. Once again, thanks for your time and response to my emails.

Got a question? Ask us!

UPDATE: Ally has been spotted again!

Links

WILD: Amazing animals in a changing world

Bioinformatics

About this blog

Updates on what's happening at Melbourne Museum, the Immigration Museum, Scienceworks, the Royal Exhibition Building, and beyond.

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