A few weeks ago we discovered a decaying pigeon carcass hidden in a nook in the garden. When examined it was little but a collection of decaying feathers and bones; it had clearly been lying in it's last resting place for some months. We managed, without too much mess, to salvage the breastbone and the skull.
Click on any of the images for larger views on Flickr
Having soaked them overnight in mild detergent (aka. shampoo) and given them a careful scrub with an old toothbrush they were allowed to dry thoroughly. Then I bleached and disinfected them twice, again overnight, in hydrogen peroxide, allowing them to dry thoroughly in between. They have then been sitting drying thoroughly again in the bathroom for a week or more.
(Whether this is anything like an approved method for preparing such specimens, I have no idea. I more or less made it up as I went along, and it seems to have worked. Being a chemist helps!)
These are the resulting photographs. The structures are amazing. Some of the delicate structure of the brain case can be discerned. So can the wonderfully intricate fine structure which is actually within the bone of the sternum (birds have very light bones filled with air-sacs which is I think what we're seeing). The sternum especially is beautiful to handle: it weighs absolutely nothing, literally no more than a feather, and it feels like the most gorgeous and delicate waxed paper, something which isn't so obvious with the skull.
Just for the record ...
The skull is 56mm from back to the tip of the bill, 20mm high, 20mm wide.
The sternum is 72mm long, 48mm high, 50mm wide.
Next time you're destroying a roast chicken (or even your cat's next mouse) stop for a few minutes and look at the amazing structures before throwing the carcass in the bin. If you really want to see what the bones are like, boil them down in clean water (you can use the water for stock! — no maybe not the mouse!), clean them, then bleach them (domestic beach or hydrogen peroxide is fine; but not acid) and wash well in clean water; leave them to dry thoroughly. Finally be amazed.
This is why I love science and natural history.