Bones That Look Like Other Bones: Rodent Bones VS Bird Bones

Note: As you can see, I’m no longer on hiatus! But there will be some changes to my blogging moving forward…as much as I love writing, I need to put my PhD studies first. This means that blog posts will not be weekly, but will come out a bit more inconsistently – basically whenever I have a bit of free time to blog! 

Hopefully you’ll still tune in for some weird, archaeological ramblings, even if they’re only every once in a while. Thanks to everyone who has stuck around this long!

Today’s comparative mini-post comes from a question I received from Trisha J. (thanks Trisha!),  who asked for a bit of a comparison between rodent and bird bones. Now, while I have written about both rodents and birds before, I’ve never actually compared the two in one of these posts – which is a bit of a surprise, as I totally get the confusion between them! They can look pretty similar,

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Herring gull skull (left) and brown rat skull (right)

Before we start, let me first preface this by saying we’ll be looking specifically at small bird bones – obviously, as you can see in the photo below, birds come in a wide variety of shapes and sizes! So we will be working under the impression that it’s easier to confusion small bird bones with rodent bones…unless you’re working with Rodents of Unusual Size, I guess?

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Herring gull humerus (left) and corvid humerus (right)

Unfortunately there isn’t an easy tip for differentiating between bird and rodent bones quickly – although bird bones are known for being particularly light in weight to allow for flight, rodent bones have a similar weight due to size. Thankfully, bone shapes are pretty distinct between the two. See some of the example photos below to see how each differ!

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Corvid humerus (left) and brown rat humerus (right)
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Corvid femur (left) and brown rat femur (right)
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Corvid ulna (left) and brown rat ulna (right)

If you’re dealing with bone fragments that are similar in size to either a small bird or rodent, I would highly suggest using some form of reference (photo or physical) to base your identification off of. They can certainly be quite tricky! You can also use small variations, such as the presence of “nubs” on bird ulnae, to help differentiation. Also remember that birds have bones that are not present in rodents (tibio-tarsus, furncula, etc.), so memorising their general shape will be helpful.

With skulls, if you have complete specimens, it’ll be pretty easy – the bird will usually have a beak attached!

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Corvid skull (left) and brown rat skull (right)

Of course, life isn’t fair and you will often have a skull fragment on your hands. In that case, remember that bird skulls, in particular the cranial vaults, have very rounded and bulbous skulls (see below).

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Jackdaw (bird) skull fragment

And if you’re unlucky enough to have vertebrae and ribs on your hands…well, good luck! Well, maybe at least with the ribs…vertebrae can be very tricky, especially when they’re very small. However, bird vertebrae tend to have a “body” (the thickest part of the vertebra) that curves inward and are a bit more narrow in shape.

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Corvid vertebra (left) and brown rat vertebra (right)

Have a question about zooarchaeology? Or an idea for a future blog post? Remember you can contact me through the blog by heading to my Contact page.

References

Cohen, A. and Serjeantson, D. (1996) A Manual for the Identification of  Bird Bones from Archaeological Sites. Archetype Publications Ltd.

Prehn, N. et al. (2018) Beginner’s Guide to Identifying British Mammal Bones. Natural History Museum. http://www.nhm.ac.uk/content/dam/nhmwww/take-part/identify-nature/british-mammal-bones-ID-guide.pdf

 

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Bones That Look Like Other Bones: A MiniPost About Rabbits and Hares

Note: Is it morbid to look at rabbit and hare skeletons on Easter? Maybe. But more importantly, please remember that caring for rabbits as pets is a commitment – don’t buy them as an Easter Day gift for kids if you’re not committed to caring for them! More information can be found here.

So, moment of truth: how long did it take you to realise that rabbits and hares are two different animals? I’m pretty sure I was hitting double digits in age before that dawned on me…embarrassing? Maybe. But it’s an easy mistake to make: rabbits and hares look extremely alike! And that’s not just limited to their outsides either…today’s mini comparative anatomy post is about the bones of hares and rabbits!

Good rule of thumb with differentiating between hare and rabbit bones is to look at the size of the bones – hares are generally larger than rabbits. This is definitely noticeable just looking at the skulls of a hare (on the left, above) and a rabbit (on the right, above).

Hares also have larger, stronger hind legs, which can also be easily seen when you compare these bones to rabbit bones – in the above photo, are two femora, with the larger and more robust femur belonging to the hare.

Despite being from different species, however, both rabbits and hares do share similar physical traits in their skeletons, with explains why some archaeologists may have some confusion when it comes to differentiating between the two (for example, compare the two tibia bones above – besides the difference in size, they’re rather similar!).

If you’re interested in more archaeological work on hares, check on the Exploring the Easter E.g. project undertaken by the AHRC and the University of Nottingham!

References

Elena, S. (2008) Rabbits and Hares: No More Confusion! http://www.orcca.on.ca/~elena/useful/bunnies.html

Langley, L. (2014) What’s the Difference Between Rabbits and Hares? National Geographic. https://relay.nationalgeographic.com/proxy/distribution/public/amp/news/2014/12/141219-rabbits-hares-animals-science-mating-courtship