ossamenta: Weasel skull (Default)
In about two weeks time I'm off to London for the Postgraduate Zooarchaeology Forum's conference. Since I'm neither a postgrad nor a PhD student I won't give a talk, but instead I will sit and listen to several interesting talks and take copious amounts of notes. It will be such fun!


- A new Viking Age female figurine has been found! Just as with the 2012 find of the figurine with sword and shield, there are lots of dress details which I'm sure will delight any authenticity minded Viking Age re-enactors.

- Keeping in the small figurine theme: A 13th century Limoges enamel Madonna found buried under Danish church floor.

- If you ever wondered where a penguin's knees are, look no further.

- The Walbrook Discovery Programme has a blog post up on animal remains from Roman butchery.

- "Let's just say an unbearable smell was emitted" - how to reduce a blue whale to a pile of bones. I'm so impressed at the size of those vertebrae! Although I'm glad I wasn't there in person, and that internet doesn't (yet) do smell-o-vision...

- One of the advantages of a British Museum membership is tickets to members' lectures. Luckily for us who a) aren't members or b) couldn't go, Mary Beard's Pompeii lecture is now online. Thanks BM!
ossamenta: Picture of an owl from a Medieval manuscript (Medieval owl)
I'm not quite sure if I had any particular plans for this Friday evening, but when my colleague came in with a robin that he had found dead outside (probably the first casualty of the windows of the new enviromental processing shed), I knew any plans would be cancelled. Skeletal preparation is not my favourite activity, but beggars can't be choosers, particularly if they aren't rich enough to buy their specimens, nor in possession of a garden to bury carcasses in.

This was the smallest animal I've prepped, and I can't say I'd love to do it again. Well, plucking the feathers was very quickly done, but as for the rest: fragile, tiny bones that I really didn't want to damage when I was removing flesh and guts. It's halfway done now: most of the meat on the limbs are gone, tendons remaining. The spine and the head are a pain in the neck to get clean (small and fragile) and the kidneys are fiddly to remove from the synsacrum. Hopefully an overnight soak will make it easier. I really don't want to spend too much of the weekend cleaning teeny tiny bones.
ossamenta: Picture of an owl from a Medieval manuscript (Medieval owl)
Rain/heavy rain was forecast and consequently my plans for the weekend involved me, sofa, good book, embroidery and not going outside more than I absolutely had to. However, that Friday evening I found out that there was a temporary exhibition at the Natural History Museum in Tring on a new bird book. And it turned out that Saturday was my only available day before the exhibition closed…

Nothing for it. Off to Tring.

The exhibition showed 15-20 exquisitely drawn bird skeletons, often ”in life” rather than merely standing up, three mounted skeletons and the book. I had said to myself that if I liked the book I would put it on my Christmas wish list, as it was £35, and it would be far better if someone else spent that money :-) . But after a quick glance through the book in the shop, I decided that instant gratification was the better choice. After all, Christmas is a long time away, and the book could go out of print. If it had only been anatomical drawings, I probably would have passed. But the text is highly informative on how bird behaviour, appearance and posture are influenced by their anatomy, and vice versa. As the author says, it’s not a book about the inside of birds, it’s about the outside of birds.

John's review post is full of info and pictures, so instead of repeating most of this, I will merely link to his blog. He didn't include my favourite drawing, a diver under water, so I'll post a photograph here. Unfortunately, what with the lighting and placement of the drawings, this one in particular was very hard to photograph, as it all reflected back in the glass. You can even see parts of the emergency exit sign reflection in the lower left corner of the glass.

 photo Tring_diver_zps4723e7d6.jpg
Diver (that's loon in the US) under water, with a fish and waterlily leaves seen from below in the upper right corner.
ossamenta: Picture of an owl from a Medieval manuscript (Medieval owl)
Last Monday I went to the National History Museum in Tring, to check some mystery bird bones against their skeleton collection. They have a huge collection, with birds from all over the world. But most importantly for my part, they also have a comparative collection, where the main bones from several specimens are collected by bone type, so you can compare your mystery bones between bones from different genera and species. This is of course much quicker than having to go from species to species. And once you have pinpointed the genera, you can if necessary go to the main collection and try to get the species right. It’s not always worth the time, as some species have minute differences and/or large overlap in size or great variation of morphological features. And that’s without acknowledging the possibility for birds from Africa or Asia being swept off course and ending up in Europe.

The day went well, and I could add buzzard, curlew, diver (either red-throated, black-throated or great northern diver) and gannet to the species list. I also did a quick genus id comparison for diver and grebe.

Photobucket
Upper humerus of diver (Gavia stellata) and grebe (Podiceps sp.)


I like the Natural History Museum in Tring. It was founded in 1892 as the Walter Rothschild Zoological Museum, being part of the Baron’s private collection. Parts of the building is still Victorian, but the majority of the galleries are modern, even if the specimens inside can be old. One of their more unusual exhibits is the domestic dog gallery, featuring, you guessed it: domestic dogs. Most of these dogs died a long time ago, and it is interesting to see how the species have changed over the years. Did you know that in the early 20th century dachshunds looked like this? Quite a difference from today, isn't it?
ossamenta: Picture of an owl from a Medieval manuscript (Medieval owl)
In the comments to the strangest animal bone-post, I mentioned bird quadrates. And since I doubt most readers will immediately get an image in their minds from that word alone, I thought I’d add a picture.

Photobucket
Quadrates from chicken (left) and duck (right). This bone attaches between the skull and the mandible in birds and reptiles.

The quadrate is one of those bones that are rarely illustrated, so when you find them it’s not easy to immediately attach them to a species or to a specific element group. Before I learned to recognise them for what they were, I often put them in the fish bones bag.

Here is a good photo of the quadrate in situ.


And in my hunt for cool zooarch blogs, I came across Zygoma, which mostly consist of very difficult mystery object posts. The reason I find them very difficult is that these specimens come from all over the world - it's not too difficult to identify the type of animal, but which of the 13 different otter species is the one in the photo? *tears hair*
ossamenta: Picture of an owl from a Medieval manuscript (Medieval owl)
My intention with this blog/journal was to post a bit more frequently than seems to be the reality. Sorry about that. Life has been busy, with lots of work, moving house and doing the last layout on my tanning essay. Soon (fingers crossed) I can hand it in!

Despite lots of work, there has been few bones worth writing about. One was quite interesting though. I had found this kind of bone before, but then as now I had no clue what it was. Often I can tell either species or bone type, but this time it just looked like nothing I had ever seen. A juvenile bone, so one would look for similarities in shape to bones from adults rather than a 100% match. Last time I gave up. This time I asked other osteologists on a discussion list (and oh what a useful discussion list it is), and two knew: it was a bird wing bone, an unfused part of the carpometacarpus. I had never seen even an image of an unfused carpometacarpus before. No wonder I had no clue how to identify it.

Bird bones
Carpometacarpus of adult duck, juvenile bird (possibly large chicken) and adult chicken
ossamenta: Picture of an owl from a Medieval manuscript (Medieval owl)
Sometimes sexing birds can be very easy:
Male and female mallard - From Wikimedia Commons

Sometimes it is difficult:
Duck skeleton

While there can be size differences between males and females of the same species, there is often an overlap, which makes it difficult to carry out a reasonably secure sex estimation. If you have a large sample, you can hopefully get two (somewhat overlapping) bell curves, but bird bones are rarely found in such quantities*.

From a European point of view**, normally there are two ways of sexing birds: presence of spurs (only on galliforms, i.e. chicken, pheasant etc) and presence of medullary bone. Medullary bone is formed in the bone shaft cavity on female birds when they’re laying eggs. This acts as a calcium buffer for the egg shell development. The level of medullary bone can vary, from a millimetre lining on the cavity to a fully filled bone shaft, probably depending on where the hen was in the egg laying cycle, and/or how calcium rich the feed is. Medullary bone are most often found in the femur and tibiotarsus (the thigh bone and the drumstick bone). Medullary bone sexing has two major drawbacks: It can only be observed in fragmented bones. Since bird bones normally are rather small, there is little need to portioning them by cutting them in two, as is done with bones from cattle, sheep and pig. It is therefore likely that we miss several egg laying hens in bone assemblages. Secondly, the method only counts egg laying hens, possibly not the preferred animals to slaughter.

Medullary bone inside a fowl femur
Medullary bone inside a fowl femur

Close-up of medullary bone inside a fowl femur
Close-up of medullary bone

Spurs are more straightforward when it comes to sex estimation, even if they only appear in a few species. However, just as with horse canine teeth, occasionally females have them too. The bone part of the spur forms separately and fuses with the bone shaft at six months of age, although this is very variable.

Male and female fowl tarsometatarsus
Male and female fowl tarsometatarsus


Sometimes spurs have been cut off, either as a way to castrate the fowl (or, possibly to prevent fights within the flock) or to make it easier to tie metal spurs on for cock fighting. Not that that was necessary, cock fighting did and does happen with "natural" spurs too. Sometimes a predominance of male fowl in an archaeological assemblage has been interpreted as occurrence of cock fighting, although, at least for the Roman period, cocks would also have been the preferred sex for sacrifice.

Medieval cock fighting, from MS Bodleian 264, fol. 50r.
Medieval cock fighting, from MS Bodleian 264, fol. 50r.

Conclusion: bird sexing is much easier with live ones!

(read more? Dale Serjeantson, 2009, Birds, Cambridge University Press.)


*: Not only are there normally less chicken on the menu than cattle, sheep and pig, but the thin bird bones are easily destroyed in the soil.
**: I don’t have the experience to say whether non-galliform birds on other continents have sexually distinct skeletal elements or not. If some of my readers know, please tell me!

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