‘Pots o’ Death’ an osteoarchaeologist at work…

Being an osteoarchaeologist, I study a variety of bones from varying species (including human remains) in the archaeological record.

There are a range of animal bones that are discovered at archaeological sites in the UK, and I find it interesting to try and tell the story of a site from the bones along with other artefacts that have been excavated.  

To do this I have started to collect my own reference collection of animal skeletons so that I can compare them to the archaeological samples. I only use animals that I’ve bought from a butchers for consumption, or roadkill specimens. I’m also experimenting to find the best method of skeletal preparation, having already blogged about maceration and the odours that go hand in hand with this process previously. Although maceration is quick, the cons. are the smell and that it works best in the summer months. I prefer the burial method as it has no smell, but it takes a long time to get results. With animals I’ve bought from the butcher I can process them by cooking, and then use a basic maceration changing the water daily for a week or so to losen the cartilage. I have a cooked chicken sitting in a bucket of water at the moment…I didn’t waste the meat.

Because of the lack of space where I currently live, I’m only taking on small birds and mammals, nothing bigger than a rabbit or a blackbird. When I eventually get a place to call my own I intend to set up a proper workshop to start preparing bigger specimens like deer, goose and foxes.

A few days ago, a friend gave me parts from two animal carcasses (cow and sheep) that she had collected from her local butcher, who was preparing the animals for meat consumption. Over the weekend I began processing these bones for my collection.

I decided to document the event and write about it on my blog. If you are squeamish avoid looking at the photos.

Cow & Sheep skeletal prep. March 10th 2012

I had left the pieces of vertebrae for a few days in a plastic bag, and they had begun to smell slightly. Not a nasty smell, but not nice, I’m not bothered by this kind of thing, but I do notice it. It doesn’t take long for carcasses to start decomposing if they are not stored in the correct environment. It’s a natural process, and means the proteins are starting to break down and decay.

First I had to find a good location. As I currently live in rented accommodation in quite a residential area, I didn’t think my neighbours would appreciate the smell of rotting animal parts over the summer. I have several ‘pots o’ death’ in the garden already, but I don’t have a space big enough to disguise chunks of cow and sheep.

Pots o’ death are garden plant pots in which I bury my collection to be processed naturally. Sometime’s I’ll leave the dead animals exposed for a while to attract insects (smelly, and often interests the local foxes), in others I’ll bury and plant bushes and shrubs in the pots (not smelly). This summer I’m hoping to excavate a few to see if there are any differences in decomposition between the varying methods. As I mentioned previously in my post, I collect these animals from the butchers, or as road kill.

The solution to my burial location dilema…my parents garden! More importantly they have a well established compost bin, complete with thousands of worms and insects, in direct sunlight. Perfect.

The compost bin was quite full, so I dug out a few bucket loads to make some space.

On Saturday I had also collected two onion nets from a local greengrocer, she asked why I needed them and so I explained. Afterwards, I think she regretted asking and looked at me like I was a loon.

I checked over the specimens, making sure the ribs and vertebrae were in good condition. I then bagged them separately in the two onion nets; cow vertebrae/ribs in one, sheep vertebrae/ribs/sacrum in the other.

The nets were strong, and had small holes to allow the insects and bacteria entry to the specimens, but the holes were not large enough to allow any of the bone to pass through. All being well the nets should survive through until next year intact, while the specimens would have broken down to leave exposed bone.

I then buried these in the compost bin, and poured the compost I had taken out, back ontop of these remains. To deter any foxes I placed a heavy herb planter ontop of the compost bin lid to squash everything back into place, filling the voids around the nets.

I plan to revisit the compost bin in a year to 18 months time to check on the remains and the rate of decomposition. Being in a sunny position really helps the decay rate as the insect/bacteria productivity is higher than in the shade, and this increases the breakdown of natural organic matter.