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,

IMG_E5452
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?

IMG_E5445
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!

IMG_E5446
Corvid humerus (left) and brown rat humerus (right)
IMG_E5450
Corvid femur (left) and brown rat femur (right)
IMG_E5451
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!

IMG_E5447
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).

IMG_E5448
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.

IMG_E5449
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

 

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s