A Murder of Crows

Today I made a flying visit to English Heritage's office in York to see the Regional Science Advisor and my good friend, Dr. Andy Hammon.  Before becoming a faceless bureaucrat Andy was once an archaeo-zoologist, so I hoped he'd be able to identify the bird type in the animal grave.

As a reminder, here is the bone assemblage recovered from pit fill (105).  Only about half of the small pit was within the test-pit, so we recovered only a partial assemblage.

It was fortuitous that on the day that I visited Andy, his colleague Dr. Eva Fairnell was in the process of cataloguing a collection of animal and bird skeletons and we had a lot of reference skeletons to hand.  My prediction that it was a pit full of pigeons was quickly demolished when Andy identified the bones as belonging to Corvids, with a single rogue amphibian bone in the mix.  The family Corvidae includes, rooks, crows, jackdaws, magpies and jays. The reference collection helped us narrow the bones down further to rooks/crows or jackdaws. Also, the bones were all from individuals that were not quite fully grown ("sub-adult").  Here is Andy's catalogue of the bones.

Juvenile jackdaw/rook/crow

MNI = 4

4 x left carpometacarpus

1 x right carpometacarpus

4 x left tarsometatarsus

2 x right tarsometatarsus

1 x right ulna

1 x left ulna

1 x pelvis

Assorted cranial and mandible fragments

1 x amphibian femur

Interestingly, one of my suspicions about the group was confirmed: there was more than one bird in the pit.  MNI = 4 refers to the "Minimum Number of Individuals" present in the assemblage.  In this case there were 4 left carpometacarpus or wing bones, meaning that there were at least four birds in the pit.

So, how to interpret four crows in a pit?  Three possible interpretations spring to mind: 1) A pet burial 2) Food disposal 2) Vermin disposal

1) Pet burial - These features are common in the back gardens of houses from the 19th to 21st Centuries.  I suspect that most readers will have planted at least one beloved pet in their back garden, myself included (sadly, these are quite often disturbed by archaeologists).  Crows, rooks, and especially jackdaws were often kept as pets, however I find it difficult to believe that four such pets would die and be buried at the same time.  Also, the stratigraphic sequence suggests that this pit probably pre-dated the construction of the row of townhouses along Acomb Road, so it was not dug in a backgarden at all.  More likely, in the mid 19th Century, this was a bit of agricultural land or open ground outside the core of Holgate village. 

2) Food disposal - The American euphemism for humiliation notwithstanding, crows were sometimes eaten even into the 20th century, and apparently remain a delicacy in Lithuania to this day.  This reminds me of the nursery rhyme containing the line "Four and twenty blackbirds baked in a pie".  Sometimes clear evidence for butchery can be found on animal bones, or the assemblage can consist of the choicest cuts of meat.  Neither is true of this assemblage.  In fact, the bones present in the pit were predominantly the upper parts of the skeleton, and we may presume that the un-excavated half of the pit contained the lower portions.  The suggestion is that the birds were buried whole and therefore not the remains of a meal.

3) Vermin disposal - Corvids can be opportunistic predators and scavengers and may well have been considered vermin by the agricultural/horticultural workers in the vicinity, and disposed of when the opportunity arose.  The fact that the crows were all sub-adult and disposed of together possibly supports this.  

I think on balance, that a brood of young crows was killed as vermin and disposed of in the pit at a time when the land was in agricultural use.  Not long afterwards, in the late 19th Century, the village of Holgate expanded across the site and I can only presume that this probably commonplace rural practice was replaced by a more urban sensitivity that most of us would be familiar with today.  

I should point out that I really like crows.

Stratigraphy!

Here I present the stratigraphic (Harris) matrix for the test-pit, the bane of many an archaeologist's life, but too useful a tool to ignore.  I will attempt to explain to the lay person as concisely as possible, but I fear I may not be up to the job really.  I won't hold it against you if you abandon this blog post now.

Anyway, here goes... a matrix is a graphical representation of the sequence of the deposits that we found in the archaeological test-pit.  Each number represents a single context or event.  Most 'events' are the deposition of layers of soil, however 'events' such as the digging of the animal grave and the foundation slot are also given context numbers, to distinguish them from the filling-in 'events' of those features.  Deposits (or events/contexts) lower down on the matrix are earlier than deposits higher up.  Deposits shown on the same level probably occurred at roughly the same time , but may not have, and the sequence of deposits doesn't give any clues about which is earlier or later.

This stratigraphic matrix is a relatively simple one, but the same system is used for much larger and complex archaeological sites.  Once this has been constructed the information about the dates of the finds from each deposit/context is added.  With these two sources of information we can construct a general sequence of events for the site.  

It is also a good way to test some ideas and interpretations about the deposits.  For example, while the animal grave was being dug I thought that it might date from the 18th Century or earlier since it pre-dated the 19th Century garden and looked like it might relate to the farm in the vicinity.  No datable finds came from the grave to indicate when it was dug, however my 18th Century interpretation must be wrong, because we can see two layers pre-dating the grave both contained 19th Century pottery types.  Put simply, unless we are to believe in time-machines, something can't be put in the ground BEFORE it is invented.

Some events in this matrix probably took place very quickly, for example the animal grave 106/105 was probably dug and filled in within a very short space of time.  Other events, on the other hand, took place over a long time: deposit 109 probably formed over millenia by a continuous process of soil eroding down the hillside and intermittently being mixed up by ploughing.  This deposit contained only a single small fragment of Roman tile, which doesn't help much when trying to determine how long the deposit took to be laid down.

The next stage of the analytical process involves constructing an interpretive narrative that incorporates all the strands of information that we have discovered.  In other words we write a nice story...

109- colluvium

Possible Roman tile.

Welcome home...

Catriona has kindly gifted us one of her jars. Here it will live for another 150 years!

105 -animal grave fill

100- unstratified finds

103- fill of structural slot

101 - The Plastic Age

Context 101 The Plastic Age - This was the topsoil and turf layer in the garden, and therefore the most recently laid down deposit. Here are some of the finds from the layer:

This is an assortment of late 19th Century and 20th Century pottery, flowerpot fragments, window and bottle glass, roof slate, and a clay pipe fragment. Also in the layer was this more modern assemblage of finds:

Here we see some much more modern finds. I would suggest that overall this is a typical late 20th Century garden soil finds assemblage; it contains flowerpot fragments, clothes peg and hanger fragments, a children's toy (dated 2010), chocolate bar wrappers (dated 1989), and evidence of a sneaky back-garden smoke break in the form of cigarette cellophane wrappers! The date of any deposit is generally indicated by the find with the latest date, in this case the toy car dated 2010. In this case however the car was probably lost and trampled into the topsoil. This demostrates how a deposit can be constantly "re-worked", and shows that the garden topsoil has probably been acquiring finds from the late 19th Century to the present day. Earthworms have an important role in the movement of such objects around in the soil; Charles Darwin wrote a paper on the subject in the 19th Century.

One feature of late 20th and 21st Century finds assemblages that will make it extremely easy to date by future archaeologists will be the huge amount of plastic rubbish.  I suspect that late 21st Century assemblages will not contain any where near as much plastic as it becomes much more costly to produce.

Cataloging.....the happy detective.

Magnifying glass....check, copious amounts of text books and laptop open...check, piles and piles of broken bits of unidentifiable stuff...check!

Now making sense if it. I am finding this part really fun, I much prefer this to being cold, wet and digging huge holes.

Just a fraction of the haul:

102

Samian ware is a fine earthenware pottery, reddish-brown or black in colour, found in large quantities on Roman sites.

[named after the island of Samos, source of a reddish-coloured earth resembling terra sigillata, similar to the earth from which the pottery was made]

107

Find 108

Flow blue pottery:

Flowing Blue was first made in Staffordshire England about 1825. While cobalt blue underglaze could withstand the heat of the kilns, many glazes containing lead oxide provided characteristic flow blue wares its characteristic depth of colour and brilliance.

Colours Flowing

The stone china base of Flowing, Flow, or Flown Blue differed from the soft-based pottery base lighter-toned china. The flowing colour was produced by the reaction of volatile chlorides upon ceramic colours. The colours and designs are applied to the pottery surface are exposed to a chlorinated atmosphere in the kiln and the vapors cause the colour to spread and blur--thus flow blue.

The Bristol-style glazed jar fragment:

The Bristol-style glazed bottles were developed by the Powell family in Bristol in 1835. The texture of the ware was coarse to moderately coarse. The ware was characterized by a buff-coloured fabric and a clear, glossy glaze. The upper part of the vessel was dipped in an iron oxide glaze, producing a caramel colour on the upper part of the vessel. The most common vessel forms were beverage bottles and preserve/condiment jars.

The hall (or haul) of treasure.

Finds dating from the Roman period to the 21st Century.

Finds processing commences.....

We're separating out the brick and tile from all the other finds. The brick and tile (CBM) was then counted and weighed before discarding. The other finds will be washed and an attempt at identification will occur!