Like some most virtually all hopefully all people interested in animals, I have a dark, guilty secret: I covet and collect dead bodies. In fact I'm of the opinion that if you're interested in animals and are not interested in dead bodies, there's something wrong with you. How can you not be interested in - nay, fascinated by - anatomy, variation and functional morphology, and how are you going to learn about this if not by looking at, and manipulating, dead bodies and their constituent parts? Few of us have ready access to museum collections, and building up a collection of specimens yourself is easy (assuming, that is, that you have at least some interaction with the natural world).
While dissection and soft-tissue manipulation has its uses, we mostly want to get the corpses we obtain down to their bare bones; preferably in the cleanest, quickest, easiest way possible. In my efforts to do this, I've tried most techniques I can think of: burial in soil, burial in compost heaps, arthropods, live yoghurt, chemicals, mechanical maceration, sun-drying, softening in water, boiling, microwaving. Some techniques work, some fail. The area is hindered by the fact that, while there is some good literature on the processes of decomposition (Weigelt 1989, Machel 1996, Carter et al. 2007), there isn't really anything like a 'how-to guide' should you need to carry it out in a controlled manner. Or, if there is, I'm not aware of it. Thanks to two of my closest colleagues I've recently been discussing the topic of controlled decomposition quite a lot. Here are my various thoughts and recollections, some of which you might find interesting or useful. If you're squeamish: err, hell-o-o, why are you here?
Soaking, boiling and microwaving
First of all, let's look at some lesser-known techniques, and at their effectiveness. On a few occasions I've soaked carcasses in water: if enough time goes by, all the soft tissues fall away, and clean bones are the result. However, this can be a very disgusting and pungent technique, you are generally constrained to small dead things, and algae can stain or even ruin the bones entirely. It works best on specimens that have relatively little soft tissue attached. The hedgehog jaws and newt and frog skeletons you see here were all prepared in this manner.
Boiling works well, but only when much of the soft tissue has already been removed. I once used it on a frog corpse and all I ended up with was a hot frog corpse. The major disadvantage is that most of us can only do boiling indoors: I'm not fond of filling my house with the stench of boiling cadavers, nor are most people I know. Stig Walsh once introduced me to the wonders of microwaving. Unsurprisingly, heating corpses to high temperatures causes skin, flesh and other tissues to come cleanly away from bones. I say that this is unsurprising because we use this technique whenever we cook carcasses for consumption. Anyway, Stig and I once microwaved a dead cat and the results were outstanding. On the down side, it took a long time (about an hour) and hence used a lot of power, plus it created a god-awful stink. If it was my microwave, I'm not sure I'd want to use it afterwards to cook food with.
Ants, woodlice and other arthropods: your friends
Time Lapse of Ants Eating a Dead Lizard - The best bloopers are a click away
Arthropods are your friends. Ants are outstanding at defleshing and cleaning the skeletons of small animals, and everyone who's ever used the internet will know this well thanks to that video where ants deflesh a gecko skeleton. Of course, the constraint here is that you need ready access to a healthy ant colony. I've never had that, and so have never used ants. Isopods - woodlice - also work well if things go to plan. An outside colony of several hundred woodlice, discovered living under rotting wood, were used to deflesh a starling corpse. Within a week they'd done a brilliant job, and a relatively clean skeleton was the result. High encouraged, I started a captive colony and got them to work on a partially defleshed (and fully eviscerated) sparrowhawk corpse. However, I've learnt that maintaining woodlice colonies indoors is difficult: they dry out quite easily and require high humidity [hamster skeleton below prepared using 'corpse-in-a-box' technique: see below].
Dermestid beetles are also used by some people, and in fact some museums have large desmestid colonies used specifically for defleshing carcasses. Back when I kept pet lizards, I used to keep a dermestid colony, but I never had enough of the insects to use them in carcass processing (they're relatively expensive) and I reckon you must have a healthy colony of several hundreds for things to work. Furthermore, I found that they chewed on the bones, leaving noticeable damage. The solution to this might be to remove the material as soon as it's defleshed. I'd be interested to hear from anyone who has experience in using dermestids, as I've heard good things.
The corpse-in-a-box technique
Flies (more specifically, their larvae) and burying beetles are also good, and particularly so because they rapidly find a carcass once it's available (sometimes within minutes, literally). A while ago it occurred to me that - so long as flies and burying beetles can get in and out of a box containing a carcass - then, that should get the dirty work done. So I put a corpse (a slow-worm) in a small plastic tub, broke some small holes in the top, and left it alone for a few months. The results were excellent. The insects got in, ate all the soft tissues, pupated, and left, leaving behind only bare bones and their empty pupal cases. The pupal cases were stuck to the sides of the tub and not to the bones. The bones were disarticulated and slightly discoloured, but that's all fine.
And on that note, do not go thinking that this method results in an articulated, ready-for-display skeleton: that just doesn't happen, and I should note at this point that I don't want my skeletons to be articulated, posed-as-if-standing show-pieces. No, I want disarticulated bones that can be handled individually. This is, of course, because I want the bones for comparative reasons and research. If you do want the bones to be assembled back into a skeleton, you have quite a task on your hands. My friend Trudie and I once assembled the better part of a Common boa skeleton from cleaned, disarticulated bones, and it took months (although we did only a few minutes here and there). If you do keep the bones in their disarticulated state, as I do, it pays to label them (with a fine marker pen) once they're identified, particularly the vertebrae.
Anyway, the 'corpse-in-a-box' technique is now my favourite method. For mammals and birds the technique is pretty messy as, even after all the soft tissue is gone, you're left with a lot of feathers and/or fur in the box. You therefore have to do a lot of rinsing, carefully discarding and draining away the water containing the dead feathers and/or fur. Because the skeleton becomes disarticulated by this process, various of the bones get entangled in the unwanted material, so you have to gently feel around in the mess, disentangling the bones and taking care not to throw them away. If you are squeamish or don't like the thought of manipulating dead feathers and/or fur, this is not for you. It is not pretty or pleasant. Some of you will remember the dead mole I obtained in June 2008. Moles actually break down very quickly (I'm not sure why, perhaps because their lifestyle means that their carcasses are covered in a rich assortment of destructive bacteria), and by September 2008, the job was done. As you can see from the adjacent photos, I had to rinse out a lot of dead fur (the black patches on the grass), but the results were worth it.
Once flies and/or beetles have gotten into the box, they need to be protected: if they die, your decomposition project is at an end. So, the box needs to be sheltered from the rain and from extreme heat. I made the mistake of leaving a corpse box exposed to the sky. Heavy rain flooded the box and drowned all the maggots that were happily eating the squirrel corpse inside (you can see all the dead maggots piled up near the wall). The results were pretty grotesque. Soaking in rainwater has softened the tissues: note that bare bone is visible on the squirrel's hindlimb.
Because the boxes I use for this technique are generally disposable containers like ice-cream boxes, I'm limited to small animals (which is ok, read on). The largest animals I've processed in this way have been such things as squirrels, kestrels and polecats (incidentally, all of my corpses come to me as roadkill, or as natural deaths). For larger animals - anything, say, bigger than a squirrel or pigeon - boxes and arthropods won't work, at least not before the stench of decomposition becomes a problem. Burial is your only sensible option.
Put them under the dirt
In my (dare I say it, extensive) experience, burial is weird in that the remains of carcasses are sometimes completely absent when you try and dig them up months later. Sometimes this is because you lose the exact spot, sometimes it's because a scavenger got their first (here in Britain this is typically a fox), but sometimes it's because decomposition has been so rapid, and so thorough, that the whole carcass has been broken down, bones and all. Or, at least, this is what I hypothesise anyway. I've lost hedgehogs, rodents, passerines and frogs in the soil, as well as various fish. Of course, all of these animals have relatively small, delicate bones, so their loss isn't perhaps so surprising. In order to circumvent this problem, I took to burying carcasses in boxes: the carcass was placed in a lidless box, and the whole thing was then filled in with sediment and buried 10-20 cm down. I tried this with two Lesser spotted dogfish (found discarded on the beach at Portsmouth, oh how I love fishermen), thinking that I'd get a few jaw bones out of it at least. But when I exhumed the boxes... nothing.
Anyway, when all goes to plan, burial works well, though it does require a long time (a year or more for a mid-sized animal). The bones may be soil-stained but they're generally in good shape and in need of only minor degreasing (this involves a day or two of soaking in water with detergent).
Beverley Halstead once wrote of a case where a dead dog was buried in an active compost heap, and had completely rotted down to its skeleton within something like a day (I think this case is discussed by Weigelt (1989), but I can't be bothered to go check). Inspired, I have on occasion put carcasses into my compost bin, and the results have been encouraging. So far, all I've done is throw dead mice and rats into the compost, and then noted over time the speed of decomposition (we compost all biodegradable kitchen waste, as should you). The problem, however, is that - even if the corpse was placed in a box - you'd have to sort the bones out from the substrate, and that sounds like a lot of trouble.
So, there you have it. I'm very happy with the 'corpse-in-a-box technique' and would recommend it to others who need to rot carcasses down. I'm interested in hearing other successes and failures as goes controlled decomposition, so please do chip in. There's one last thing to discuss: unless you have access to lots of land, where do you do your decomposing? My garden is just about big enough for me to hide away boxes and let nature take its course, without anyone noticing. But when larger carcasses have been involved, I've had to be inventive. I'll stop there, but let's just say that universities rarely keep a close eye on their more unkempt areas...
Refs - -
Carter, D. O., Yellowlees, D. & Tibbett, M. 2007. Cadaver decomposition in terrestrial ecosystems. Naturwissenschaften 94, 12-24.
Machel, H. G. 1996. Roadkill as teaching aids in historical geology and paleontology. Journal of Geoscience Education 44, 270-276.
Weigelt, J. 1989. Recent Vertebrate Carcasses and Their Paleobiological Implications. University of Chicago Press, Chicago.
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An excellent article Darren. A dead tawny owl was found a year or so ago at the park I volunteer at, so having read about burying in a container method in a couple of amateur naturalist books I dug a hole put some of the dirt in the container (with holes in the lid) with the owl and buried it. But a few months ago someone pulled up the marker for where it is and It will take a while to find it, but when I make the effort I'll let you know the result!
Have you ever tried the carcass in a tank full of tadpoles ( at the carnivorous stage obviously) method?
Hi Neil - yes, I have used tadpoles, but this was more to do with feeding the tadpoles than defleshing the carcasses. I used it on adult frog carcasses but don't recall how well it worked. Nowadays this option is not available to me as frogs are locally extinct where I live. I'd certainly be interested in trying it again however.
I've had some success with adding BioTek ("biological" washing additive, some sort of lytic enzyme, I assume) or "Biological" washing powder to the water method (a stoat and a hedgehog, came up lovely!)
Larger stuff (ducks and gulls) shallow burial. Interestingly, some cetacean bones from an archaeological context (about 200 years old, I think) still stank faintly of rancid fat....
I love articles like this - it is so good to know I am not alone in collecting 'dead things'. I usually bury corpses, sunk in a container or even in a plastic bag as I was warned that I otherwise risked losing bones. I have never actually lost a skeleton this way and they clean pretty well if you are patient enough to leave them - I had a rabbit take two summers once. You do have to carefully sieve the soil for the small bones though. However the main problem is if you then want to plant flowers in the area - I spent time on Saturday pulling up a greater-blacked gull I had buried as I wanted to sow seeds. The now featherless gull is sitting in soil, in a bag out on the surface.
Alternatively to avoid this problem I have buried small birds and mammals in plant pots and left them on the surface. It is easier to keep track of them and you minimise the smell by burying them. In warm weather I often move soil off the corpse to encourage flies to lay their eggs. I have also tried just leaving the corpse in a covered tub with air holes. In warm weather this is by far the quickest method and saves you having to sift the soil for bones, but it can smell quite rank.
I am often impatient and have tried macerating partially decomposed skeletons in water. Without being able to keep the water warm I wouldn't usually bother with this method as I found the bones incredibly difficult to clean and have ended up leaving ligament attachments on the bone. I am also trying to pluck birds first as feathers get in the way and am finding that the more I process the less grossed out I am doing things like this. I keep everything in my own garden (or at times my poor suffering parents), but it can get quite full. I think right now I have eight decomposing bodies - most of them sea birds.
My cats once brought me a bat (don´t ask me how they got it, I have no idea) and I tried to get hold of the skeleton. Since we have multiple ant colonies around the house, I put the dead bat under an upturned flowerpot with a little rock placed under the edge. The flesh was gone in about a week, but hair was all over the place and also a bit of skin, especially on the skull. I was thinking to boil it next and use the water to separate the hair from the bones but sadly the cleaning lady destroyed the specimen before I could act.
As a grad student we started a dermestid colony in a fish tank, from a biological supply house starter kit. It ran happily for a year, fed on roadkill; I defleshed a barred owl pretty well with it. Keeping a constant supply of food going in and keeping it "hot" was tricky though, and the beetles preferred dried flesh to fresh, so I would recommend gutting, skinning, and sun-drying corpses first. Having said that the National Museum where I worked had a big beetle room (in a concrete bunker well separated from the collections) with multiple hot tanks, which could clean a whole kiwi in just a few days. This same museum had macerating tanks in the basement for dolphins (hosing brains out of a rotting dolphin skull is most unpleasant, surpassed only by sieving the bottom of the tank for the teeth). But I was still hearing the war stories from those who years before had skeletonised the elephant from Wellington Zoo. Buried for a year, the carcass turned out to have mummified rather than rotted, and had to be defleshed by hand. Those involved had to burn their clothes and cut off their hair afterwards.
I've read stories about how incredible the amount of fat in whale bones is.
Darren:
Hmm. That reminds me of what Dr. Mortimer said when he met Sherlock Holmes (in The Hound of the Baskervilles):
'It is not my intention to be fulsome, but I confess that I covet your skull.'
Don't you ever preserve the skins of mammals?
David:
Cats are very good, ahem, collectors of all kinds of small mammals. Even bats on occasion.
Awesome stuff so far, thanks everyone.
Dartian: nope, I don't have the means to preserve skins. I freeze things instead (I have a freezer full of dead animals). Many of my specimens (including a long-eared bat and a collection of British finches) are indeed cat kills - though my own pet cat is not the guilty party.
Cats are terrible for killing things - I watched a cat kill one half of a mating pair of starlings last week. As it wasn't my cat I wasn't presented with the dead bird, but I do have a lot of cat prey in my collection.
Oh and Darren, how locally are frogs extinct around you? I thought my parents still had frogs in their garden and they are not that far away.
Makes me feel normal knowing I'm not the only one.
My wife made me get rid of my skull collection when we were selling our previous house. She said with all the bleached skulls in the back garden potential buyers would be scared off. I thought it beat garden gnomes any day. The sheep and rodent skulls were not so bad, but the horse skull was my favourite at the time, and it was the one she had the biggest issues with.
She did buy me a museum quality reproduction Smilodon skull for an anniversary present though, so I shouldn't moan.
As for microwaves, I recall 20+ years ago, when I was still living with my parents, using the microwave to sterilise compost for sowing fern spores. My mother went balisitic - to be fair the microwave did rather stink. I still occasionally use my own microwave for compost sterilisation (not perfect, but good enough for my purposes) but make sure its when my wife is not around and there's enough time for the smell to disipate.
I guess it goes without saying that of you bury a corpse to render it down to the bones that you (a) mark the position, and (b) don't wrap it in a plastic bag. I recall a neighbour of mine burying a dead pet parrot well wrapped in a plastic bag in the garden - over a year later while digging in the garden his wife dug up the body, the bag had greatly slowed decompostion, so the parrot while much the worse for wear was very recognisable as their pet. Its fair to say his kids were not at all happy - looked rather like it was audtioning for a part in a zombie movie, has anyone ever done a film with a zombie-parrot?
Mark:
Dunno about that, but Monty Python once did something relating to a dead parrot...
Auckland Museum has a small mammal corpse (can't remember the species) where the veins and arteries have been filled with blue and red plastic respectively, and then the whole carcass left with dermestids; the skeleton was held in relation to the circulatory system after the flesh was gone, and it made an amazing specimen, still articulated.
Well, I don't collect dead specimens, but I am a little obsessed with photographing any carcasses I find on my trips, no matter how badly decomposed. These have included crabs, fish, and even a bullfrog that tried to cross the road and got turned into roadkill.
I've got a collection of photos of dead things over at my Flickr:
http://www.flickr.com/photos/hai_ren/collections/72157609374419784/
http://www.kelebek.gen.tr
Thanks for the info on the various techniques! I once tried soaking an anole in water, but after more than a year it was still not complete and it really looked like something really smelly, so I got rid of it. After that I buried an Antillean ghost-faced bat (Mormoops blainvillii) in a box and the results were very satisfying! I used the same technique on a snake and two birds, but I've lost the location; it's been about three years now, maybe I should really try to find it when I go back home.
There's also the stuff that can be found in the field, already skeletonized. That way I've managed to get a couple of horse's skulls, a nearly complete goat skeleton, a mongoose skeleton, dog and cat skulls, bat skulls, lizards, frogs, etc. Luckily my mom is cool enough that she lets me store that stuff in my old room while I'm away in grad school.
I tried water soaking to clean up the skull of a white-tailed deer, and must say I was less-than-impressed with the technique. The head had decayed naturally on the surface by the roadside for about a year before I collected it, so it was only covered with dried skin and sinew and was rather mud-stained, so I thought it'd be an easy job for soaking.
Yet it still took about six months of soaking for the gunk to fall off. By then residual fat in the bones (I presume) had stained the skull an ugly yellow/brown. I confess I resorted to diluted hydrogen peroxide at that point, which turned it a sparkling white although I remember reading it can be damaging.
We have lots of road-kill here (deer, raccoons, ground-hogs) but the difficulty with the simple deer skull put me off trying to get a full skeleton of anything else.
Not that I'm very interested in the matter, but why not try to help... So, Darren, have you ever tried a pressure cooker (what we French call "cocotte-minute" and use very commonly) ? It should be more powerful and less messy than mere open boiling.
Wow, I never picked anything dead other than already clean feathers (of which I have good collection).
The reason is that if species-specific virus jumps to you, it is usually very serious to fatal. But it can be just my phobia. ;-)
Excellent article Darren, so this is what you meant about the "body farm". However, it doesn't look like the ants would do as well of a job as one would hope; in the above video you can clearly see them haul off the legs of the poor gecko, as well as the foot bones. The "body box" method does sound interesting, but I fear I will be unfortunately unable to pursue it, as I am lazy and the people I live definitely don't want any dead bodies in their house (raccoon or otherwise). If I ever do have to clean a carcass, I might as well get a "death microwave" and just nuke it. Of course, one must wonder what would happen if you put an antelope carcass in the microwave (would it even fit?)
I used Biotek and hot water on the remains of a sheep.. with this technique it is important to control the temperature, the enzymes are most effective around 30C. Which kind of keeps the smell down too!
I found the sheep on the isle of Skye, where I was hiking with my girlfriend. I happened to have my dissection kit with me, and when we noticed the sheep she told me to go ahead, we'd catch up later.. very considerate :-) I must have been quite a sight for other hikers, I noticed a couple quickly looking away & losing their friendly smile when they connected the dots..
Of course, calling them back to try to explain would only have made matters worse.
I think the problems with algae on bones in water tanks can be very easily avoided by shading the tanks. I have once seen a documentation about an alligator farm in Florida or so, where a guy cleaned the gator skulls by throwing them is a big barrel with water. In subtropical regions this is surely a very fast way to deflesh even bigger skulls and bones, and I suppose you get rid of most fat inside the bones. But I suppose this stinks horribly.
Great article Darren. I have been interested in various animal skeletons for some time now and while I usually prefer to pick up already skeletonized corpses; on occasion I find something that I must drag home. My wife is not very amused by this. In the summer I have found that for small snakes and mice and similarly sized specimens, simply covering them with some kind of screen that leaves them exposed to insects, but not scavengers, works well. Ill have to start a compost heap this year and see how that works as well.
An old professor of mine told me about a rhino carcass from a zoo was that left on the roof of a university building for months,the stench emanated for miles. If only all places of learning were so accommodating.
That parrot mentioned above isn't dead, it's resting.
i read a story a while ago of a community somewhere on one of the North American coasts that had buried a beached, dead whale back in the 1980's, which recently (within the last few years) was dug up by a museum hoping for nice, clean bones. only to find it wasn't even half decomposed yet, and the rancid fat well and truly soaked into the skeleton. i should try to find that link again, it made fascinating reading...
I wonder if anyone collects MRI scans or x-rays of the dead animals they keep finding. Obviously it would be a massively expensive and laborious task, but I wonder how much new data and new discoveries such a catalogue would reveal.
Then you have to visit your library and check out the video of 'The Relic' to watch. You'll love the hot parts, especially when the heroine hides in the massaration tank.
What effect, if any, is there of gutting/eviscerating the animal first? I'd think that'd reduce the stink, but it might also cut down on biological activity and lead to mummification.
Everyone should remember that there are laws in the U.S. and other countries which prohibit the collecting of certain animals (e. g., the Migratory Bird Treaty Act of 1918). These laws do not differentiate between live or dead animals and also extend protection to nests, eggs, and even single feathers. Furthermore, these laws also pertain to animals found on private property. The Migratory Bird Treaty Act (which also includes the U.K., Canada, and Mexico)protects over 800 species of birds, many of which are fairly common. I'm not saying that collecting and obtaining specimens for osteological collections is bad, I'm just saying make sure that when you do so you educate yourself so that you are not breaking any laws. Believe it or not in many states in the United States it is illegal to collect roadkill for any use (including eating).
Stig and I once microwaved a dead cat and the results were outstanding.
This is, objectively, the greatest thing ever said by anyone, ever, in the history of the universe. Even in context.
Out of context, it's even better than that.
Outstanding post. If you could make this a regular series, covering whatever you've got 'cooking' at a given time, with before and after photos, I'm sure fame and fortune would follow. Or at least megatons of hits.
Bill: many thanks for that. I meant to add a disclaimer somewhere that the rules on collecting carcasses differ between countries, but forgot. In the UK, you're ok so long as it's not a legally protected species. Why is it illegal to collect roadkill in some states? This makes sense if it's to do with preventing the spread of disease, but - if not, it seems daft.
Matt: ok, we have a deal. Glad you liked the microwaved cat line.
An osteologist friend of mine swears by Biz detergent and Adolph's meat tenderizer as a fleshing solution. "They're both designed to beak down complex proteins," he says, "and what is flesh, if not a complex protein."
Hi Darrin,
I have also had success with medium-sized animals and skulls by first defleshing as much as possible with a scalpel. Then I just barely simmer the remaining carcass in a (laundry) borax and water solution until the flesh loosens. Afterward, a little more work with a toothbrush and water cleans them right up.
In my state in the US, people can apply to the state for salvage permits for roadkill and other dead vertebrates, excluding birds, but these are only granted for legitimate research purposes. Collection of birds requires a federal salvage permit, which is difficult to obtain even for research purposes. I believe that the federal fine for possessing any migratory bird remains,including a single feather, is $10,000. So, folks, be very careful about scraping up that roadkill!
I really enjoy your blog!
Why not collect wild beetles yourself? They should be fairly easy to obtain from old roadkills. My colony was started from a few dozen adults I collected out of my compost bin (there was a mostly-defleshed Cervus skull in there), and grew large enough in just a few months to process entire mole-size animals in a week or so. The problem with these guys is that you need a steady supply of food in proportion to the size of the colony you want.
I keep my colony outside on the porch in a plastic terrarium, sealed inside a metal garbage pail to keep scavengers out. At least with a small colony, it's very important to keep flies out as maggots reduce a carcass to ooze that will drown the beetles. For this same reason it's wise to freeze everything solid before introducing it into the colony. For larger specimens, defleshing helps when feeding a large specimen to a small colony.
All in all, I find that dermestids work much better than leaving carcasses out to rot. Maggots always disarticulated the smaller skulls I tried, whereas the beetles have produced perfect results with species as small as Sorex shrews.
Here's a good page on dermestid cultivation from the University of Michigan's beetle room: http://www.ummz.lsa.umich.edu/mammal/dermestid.html
I'll second Matt on the merits of the "Stig and I ..." line. I don't know if it would make a better bumper sticker, T-shirt, blog tagline, or boy scout troop motto.
Pressure cooking is a good way to get the bones into edible condition, if that's what you'd rather.
It may not have been the bag that slowed the decomposition of the parrot: traditionally they take a long time to decay. There is even a poem about it by Skelton:
Parrot is a fair bird for a lady.
God of His goodness him framed and wrought.
When parrot is dead he doth not putrefy,
Yea, all things mortal shall turn unto nought
Save mannes soul which Christ so dear bought,
That never can die, nor never die shall.
Make much of parrot, that popinjay royal.
Or is this just a superstition?
Funny, we had a similar discussion over Laleaps about a year ago.
Many thanks, Chelydra, for that link to the U Mich dermestid page.
Speaking of Chelydra, I processed two dead snapping turtles back when I was living in Oklahoma. I told the story of one of those turtles, a mummy that I macerated in water, here, but I didn't get around to telling the other story until now; go here for the second, much more entertaining story.
Thanks to all for sharing the info and stories. Let's keep it rolling!
Oops, apologies to Brian - I had read that article but had forgotten it. Thanks for the reminder Bora.
There seem to be states that forbid everything that's icky. Which states are it where collecting roadkill is illegal? Oklahoma? Alabama? South Carolina?
Hi David,
I have no idea why it is illegal, unless they think it might lead to poaching by car(it happens)of species such as deer or furbearers, if they allowed it. And, I am in New England, not the south or west.
Cheri
Some farmers claim you can compost whole hogs swiftly and without odor by burying them in sawdust. No, I don't know how swift and I don.t know the effect on the bones. And yes, 10% hydrogen peroxide gets bones sparkling white.
Hello all, respect to mantain dermestid colony, i found useful to mantain a steady food supply to give them some dry cat food when they not are defleshing something...
Well, animal protection laws...
Happily, I never heard of anybody being prosecuted, and perhaps no sensible court would prosecute you.
Darren, Many years ago, when I wore a younger mans cloths, I was a zookeeper. In any zoo, critters die from time to time, for various reasons. We kept a collection of skulls , and one of my duties was cleaning them up. I tried the boiling technique, but it required close attention, and since I had lots of animals to feed and care for, that didn't work too well for me. I found what worked best for me was placeing them in water with an enzyme type septic tank treatment material. At the time the one I used was called "Bio-sure", I think. Dissolved the soft tissue like gang-busters. Just a rinse and they were clean. Occasionally they required a second treatment, and maybe a little bleaching to whiten them up, but a very quick and relativly clean way to get the job done. Have a great week, God Bless, Bob
Excellent article. You might avoid the feather/fur problem by skinning the carcass before placing it in the box. I've always used composting but will try your method, it sounds effective.
Darren, from what I remember about the boa skeleton was that it was retrieved by Dave Martill from an open sewer and thus found in an environment with a presumably high proportion of digestion-related bacteria. The effluent systems we design can munch their way through pretty much anything so there seems to be a lot of merit in Bob's method - aside from septics being rare in England and the treatments aren't readily available.
When I was a little 'un my brother an I used to wander into the swamp next to our house and bring swamp snakes back, we turned up with a king brown once which dad took to with a machete (I was 2 and very stupid, as all children are). The green tree ants reduced it to a perfectly articulated skeleton in a single day. The Gold coast wasn't so developed back then...
Sad to say, the prohibition on collecting roadkill is to discourage people from feeding the specimens' fleshy parts, preparatory to cleaning and mounting the skeleton, to their kids.
As Cheri notes, one rationale commonly given for regulations against collecting roadkill is to prevent vehicular poaching or the use of roadkill collecting as a cover for conventional poaching. I've known many amateur roadkill collectors (including my father who was fond of serving it to us for dinner) and have never heard first-hand of anyone getting prosecuted for it, although there have been some high profile cases here in California of people getting busted for picking up raptors.
Unfortunately, there doesn't seem to be any online compilation of laws pertaining to collecting biological samples, and much of the information out there, on taxidermy forums and such, appears to be misinformation. Given that Darren's estimation of his readership's hobbies appears to be on the mark it seems such a resource would actually be quite useful.
Doesn't anyone use the old bury-in-an-anthill method nowadays? It usually works beautifully, though you should use a nylon net bag to prevent the ants from carting off the smallest bones. I've heard that in the US you need to stake the cadaver down to prevent mammal scavengers from carrying it off, but that does not seem to be much of a problem in Sweden.
Nordenskiöld used a variation when going through the Northeast Passage in 1878-79. He hung his cadavers over the side in a net bag and let the marine scavengers do their thing. Apparently that worked OK too.
Ah, that makes sense.
@Tommy Tyrberg
Stake the carcass, naturally, using ash wood. ;-)
Better reason to leave the corpse in the wood is, as Ted the toad said, if you don't eat yourself leave it to somebody needy. Chips Hardy, 'Every day a small victory'. Did you read that? Just came across my mind thinking about rural countryside.
I'm too lazy to read through all of the comments, but if you have yet to find a dermestid person to answer your questions just shoot me an e-mail. I keep multiple thousands of them to process mice for skeletal analysis.
I am blessed with access to our pathology dept's big boiler, which can do ~elephant bones; boil overnight and then soak ~1hr in 10% bleach solution, then dry, coat with clear varnish to preserve the bone surface, and glue any bits back together with No Nails (like caulk). Works great! Just boiled up a baby elephant's pelvis today... life is good.
When I boil baboons (skulls and first two verts) I tend to set them in for 7 days; it seems to be the perfect amount of time, and is just a few days prior to the boiling beginning to affect the bone morphology. Any longer and they warp.
Years ago I read of a project where children were instructed to soak a chicken leg bone in vinegar for an extened period of time, this caused the bone to get rubbery and would actually allow you to tie it in a knot. When allowed to dry it was supposed to be an interesting conversation piece. So of course being the overachievers we are, we bought a cow femur from the butcher and tried cleaning the remnants of flesh from the bone to allow us to soak it for the same project...only on a larger scale. Well, it stank and it was taking forever, so we decided to bury it in the yard and let nature take it's course. So in the middle or a rainy summer night there we were, under an umbrella in the dark, digging a hole in the garden under the watchful eyes of our nosey neighbors. About halfway through the process it dawned on us how suspicious we must look. :) We also forgot exactly where we buried the bone so we never got to finish the project! But it was worth the laugh!!
There was actually a cinema movie entitled "A Zed and Two Noughts" made in 1985 specifically on the subject of zoologists and animal decomposition.
You should watch it Darren, but I will not spoil the ending for you. Perhaps you could be in the sequel.
I've had good results with defleshing roadkill, up to the size of a female bobcat, in a small box that I made entirely from 1/4 inch metal hardware cloth (also known as rat wire). I set the cage over an anthill, preferably in warm weather so that flies can do their work as well.
I have not tried to deflesh a carcass in cold weather, but I have wrapped winter-killed animals in several layers of plastic wrap, then double-bagged them in freezer bags, and kept them frozen until warm weather returns.
I suppose it should go without saying, but I have learned that you have to stake the cage down, or else a dog or raccoon will try to carry it away. And you want to place it downwind of the house.
Most of carcasses I've cleaned myself have been left out in the open or in slightly open plastic bags. My dogs kill a lot of rats and a few birds, so I usually just put them all in the corner of my backyard on the surface of the soil (it's fenced in, so no big scavengers can mess with them) and after a month or two its nothing but bones with a few dehydrated tendons and a good deal of skin. After that I do a little boiling and a soak in hydrogen peroxide and end up with some relatively nice looking bones. The coloration varies, sometimes they're brown, sometimes white, I think it just depends on oh dirty they got on the soil and how long I let them soak in the H2O2. I think I need better cleaning methods though.
I did an experiment once with some chicken drumsticks, put three in a bucket of water, three underground, and three on the surface. I did this in my front yard, so the surface bones where gnawed on by stray dogs the first day and looked horrible. The underground bones took about a month and were pretty dirt stained, and the ones in the water still seemed to have a lot of left over tissue inside, because they were pretty pinkish and stunk more then anything else I've ever worked with.
I don't know if this has been posted yet or not, but I've had lots of luck with a "death box" I keep out back.
It's just a 1 m square wooden frame with no bottom and a poultry wire top. I add my specimens underneath it, replace the box, and put some heavy rocks on top to keep scavengers out. I've done quite a few medium-sized animals in it, with excellent results. Right now, I have a fox, mink, and 2 large turtles in there, all comfortably separated.
In warm months last year, I had a large Canada Goose ready to degrease in 2 weeks! The stench can get pretty bad, but it never lasts more than a couple of days. I also noticed that adding specimens over the winter months ceases all stench altogether, even when it warms up.
Anyway, just my 2 cents on one of my favorite hobbies!
Cheers!
Darren, I'm exuberant and astonished that you have found time to blog in detail on this long-anticipated topic at so busy a time for your family.
Thanks very much!
I'm a beginner at this so I'm very glad of the many shared tips here.
This post, and the warmer drier weather, encourage me to now try retrieving my various by-now-skeletonized dead finds: from their plastic trays of soil secreted in hollows beneath various paving slabs around the outhouse behind my home. Since this is a communal area, I have to be somewhat circumspect with my inhumations and exhumations. The garbage bins stored there mean that any occasional smell (noticeable close by, even for a small rotting carcass) is less likely to draw attention.
I think a well-vented, dedicated attic area is called for, before I can proceed with further processing. I'll post results when I can.
Meanwhile thanks again Darren and all commenters!
A very fascinating essay! :D
I had a strange experience the other day with the remains of a Brushtail Possum (Trichosurus vulpecula). I was walking down the street, and I saw a strange fuzzy object laying in my path. After my momentary impression that it was a giant catterpillar, I discovered that it was the tail of a possum.
On closer inspection, the tail appeared to be dry, with the fur still covering almost all of it. Where the skin ended there was only bone and sinew sticking out. What would have happened to the rest of it? Is it possible that the rest of the animal had completely decomposed?
My best guess is that it died and it's body was devoured by a domestic dog or similar, leaving the less meaty tail alone. Do you have any idea what would have happened to the rest of it?
What is this? Seriously I'm not a troll and I'm not critising your "hobby" but what do you want these bones for? I've never heard of people doing this other than scientists so whats the deal?
Hey Tim,
Possum tails are not highly vascularized (ie. not much liquid inside). I would say you are correct; at least with the Virginia Opossums I deal with (Didelphis virginiana), the tails have a tendency to mummify shortly after death, also making them more brittle where it connects to the body, and not that palatable. I would say your mystery scavenger probably just made off with the best parts, whether by his choice or not.
Mikekoz68,
I understand your curiosity, but I'm guessing many on here ARE scientists (whether students or paid researchers), and the cornerstone of any good paleontology or vertebrate zoology department is a "Comparative Collection", the skeletal remains of as many different individuals of as many different species as possible. Also, the specimens I collect are not usually for my school's collection (unless it's something I know we need), but for my home comparative collection, specimens that I know will benefit my research in the future. Hope it helps, and just know, if you ever decide to venture into the science of roadkill preparation, you will love it too!
Jeremy
Ah, thanks muchly Jeremy! That fully explains it :)
Ah, look what I've been missing, not checking the blog for a few days. This is the real stuff!
Hmm, my first experience of this involved a lapse of minutes rather than months; I was four or five, and wanted to see how long it would take a lizard (Cryptoblepharus virgatus if I recall correctly) to fossilize. (Not sure how it died, but this was at school with a lot of kids running around, so tiny animals can get trampled accidentally) I checked only a few minutes after burying it (in a flower bed) and it wasn't there! At the time, the obvious explanation for absence of the body was resurrection, but I didn't regard this as proved. I later repeated the experiment over more extended periods, and found nothing of a cat but a few teeth after a couple of years, and less than half of a Bluetongue Tiliqua skeleton after a few months.
I've boiled a crocodile for a whole day; also tried ants, and isopods (we call them slaters; I'd seen them clean up small lizards, nice work despite chewing through thin bones; and heard they can deal with specimens originally fixed in formalin after long enough soaking to dilute it, but I think the python was too much for the colony, and it all got too ammoniacal for indoors), maggots in boxes, but the best results I've had are from dermestids (easily collected with roadkill around here), after skinning, evisceration and semi-drying. Unlike maggots, the skeleton stays more or less articulated.
For small reptiles I mostly dissect or pick off most of the flesh, then use short dunks in chlorine bleach + detergent, followed by longer soaks in (preferably running) water. Yeah, bleach is bad, but quick.
I dug one out of a sand dune, and learned all about adipocere; actually, I stopped eating Vegemite for quite a while after that.
Tim M., possum tails are usually the only parts discarded by Powerful Owls (Ninox strenua) - I think an adult Brushy would be too much for them, but a young one would be a nice meal (they eat adult Ringtails).
As Digthepast said above, macerating with enzyme detergent and/or meat tenderizer works pretty well. Best to skin, gut & remove as much flesh as possible beforehand. The maceration water will have to be replaced periodically as the enzyme and detergent lose their oompf. The process takes a while though.
Iâve used dermestid beetles with excellent results. Here in the Western U.S. you can often find dermestid larvae under road kills in the dry summer months. Keep the colony in an aquarium with a screen lid. (Youâd be surprised at what kinds of materials they can manage to chew and crawl their way through!) Feed cat or dog kibble. Prepare the specimen by defleshing as much as possible and drying it thoroughly. Dermestids like their meals pretty dry. Keep an eye on the dermestidâs progress and remove the bones as soon as theyâre done. Rinse the bones in a weak solution of ammonia with several changes progressing toward pure water over a couple days. Once the water is basically clean, youâll have to get all the bug larvae out of the nooks & crannies, like the nasal turbinates. Finally, rinse with hydrogen peroxide and dry. Most of the dermestid smell should then be gone. If not, set the bones out in the sun for a week or two. Be very careful with bleach â best not to use it at all.
If you live near the coast, you can put whatever you want to clean in screen cages and anchor them in a quiet tide pool to let amphipods do the work, which theyâll accomplish very quickly.
Some years ago I worked on a project in which we macerated the digestive tracts of Northern pikeminnow (a predatory fish in the Columbia River) to obtain the bones of their prey fish contained within the guts. (Including juvenile salmon, which is what the whole thing was all about.) Pikeminnow (formerly âsquawfishâ) use a non-acidic digestive process, so bones are not digested. We processed thousands and thousands of guts. The technique was to pour a solution of porcine pancreatase and sodium sulfite (20g/l and 10g/l respectively) into a plastic bag containing the guts enough that the guts floated a bit, incubate overnight at about 100 degrees Fahrenheit, pour a little dilute solution of lye in the bag the next day, swish it around a little to dissolve the fat, pour through a fine-mesh sieve and rinse with warm water. The result was perfectly clean, white, odorless, completely disarticulated bones. Even the tiniest bones, e.g. from small stickleback, were recovered. I also used the technique on fish as large as pan-sized trout to obtain a reference bone collection. The drawback is that the chemicals are expensive and, in the case of sodium sulfite, toxic and flammable. Also the incubation stage stinks beyond belief. But, if you need to macerate industrial quantities of small animal skeletons in a hurry you canât beat it.
mikekoz68: âWhat is this? Seriously I'm not a troll and I'm not criticizing your "hobby" but what do you want these bones for? I've never heard of people doing this other than scientists so whatâs the deal?â
Itâs a bit like collecting orchids. Orchids are complex, diverse, aesthetically pleasing, reflect a bazillion years of evolution, have strange, even bizarre, life histories, take care and some knowledge to collect, and spur curiosity.
WTF?
"use a non-acidic digestive process - WTF?"
Pikeminnows and other cyprinid fish have no proper "stomach" and no acidic phase in their digestion. Bones of preyfish that are quickly demineralized in say, a bass's stomach, are left untouched in a pikeminnow's guts. It would seem that evacuating all those bones might be a bit uncomfortable, but then I've never asked a pikeminnow.
The Ontatio Science Centre in Toronto had a whale's skeleton on their roof for about a year while it bleached or de-fatted or aired out.
I found a freshly road-killed mink on Manitoulin Island (Northern Ontario) a few years ago but I just photographed it.
cfrost wrote:
Do they actually need to? or do they just build up a lifetime's collection? I'm serious.
I know nothing of these fish but think it would make an interesting bit of research.
Possibly indigestible bone is a small enough proportion of prey items that its retention in-gut would be feasible? how much prey do they eat in a lifetime, and what period is that? how much of their prey is bony teleost fish, and how much non-bony - cartilaginous fish/molluscs/whatever - that might digest away? how distensible/durable are their guts? do the bones eventually align and pass out of body, or disintegrate by a non-acidic process?
Loads of questions arising...
that's one of the things that make this such a great blog!
great post! I have used NaOH in warm water to clean bones of residual tissues. it worked well on big animals such as an almost complete horse skeleton and a cat corpse, both of them found in 2001, and a Eretmochelys imbricata mummy I found some three years ago. However, this is not a technique to work with small animals, rodent skeletons got much damaged with this technique. I still have to dig out a cat corpse I buried in a park in front of my house almos two years ago.
The isopod technique seems to be useful here in my country, where woodlice are so common.
Of course, NaOH after defleshing the carcass and to remove ligament and fat remains.
Thanks for the great article. Another one here with the same dark, guilty secret...
Tim, re brushtailed possums. Was the tail under a power line? I often see remenent tails hanging from power lines where possums get electrocuted. The body rots off quickly but the tail is often left hanging from the line until dislodged by wind etc. The are always dry, have the od caudal vert stcking out from where the body dropped off, and usually have the end of the tail curled over from where they were attached to the line.
If I wanted to get rid of a dead cow and I couldn't bury or burn it, how could it be done? Since I live in Arizona could I put the animal in an air tight body bag with an air vent through activated carbon to flter the odor and leave it in the sun to cook and dehydrate.
I know this is an old blog entry, but I thought it worth throwing in my 2 cents for anyone reading this years later.
The main problem with the box technique (feathers and fur all mixed up with the bones) can easily be avoided by skinning the animal before putting it in the box. If you are dealing with a fresh specimen, this is actually very easy to do. A snake of almost any size takes literally no more than 5 minutes and a squirrel-sized mammal about the same. Birds can be a bit more fussy, but I imagine it would still be less effort than removing the feathers from the bones later.
Hi there Darren
Long time no see. One of my Chinese Water Dragons died a fortnight ago. After 8 years I was still a bit too attached to him as a pet to opt for the full on recreation of the infamous tortoise experiments in my new back garden, so we put him in a box (with holes)and buried him. I'm not against exhuming him in a few months to make some observations though.
Fortunately the other is doing just fine at 12 years old.
Would be good to catch up some time :)
being a teacher of a school i found your articles more value able now i am going to to have something for my students to observe.thank you
My university has a mountain lion skeleton. After a necropsy the corpse was buried on campus at night, which resulted in a police officer investigating the scene, wrapped in I believe chicken wire. I've been told that it's a complete skeleton but I'm not sure how well small bones would have fared with that method. After I believe a year they dug it up and it was still... gooey so they gave it another year and it was fine.
Hopefully I'll have a chance to try this myself in the future.
Hey, nice to see they're others who enjoy this odd hobby. My method is more towards using a crock pot to soften the tissue and strip the bones, then soak them in hydrogen peroxide and let the sun do the rest. However, my friends, (who are wonderfully supportive) helped me keep tabs on a dog once. It did pretty well except for the meaty legs. The muscles/tendons stuck to the bone like cement, and I was hard-pressed to get it off, but the result was well worth the hassle.
I would like to expand my lab, but am afraid to let an animal decomp randomly in the desert somewhere without worrying about it 24/7, also not the hassle of buring it on someone else's land.
I maintain collections of mollusc shells, echinoderms, insects and other arthropods and fossils. I have collected and dryed many insects.
I spot roadkill carcasses many times, and go in regular intervals to watch some of them, but never think to take one. Is collecting carcasses dangerous?
I am very interested in getting a clean, and, if possible, articulated turtle skeleton. How can I do these with minimal smell and risk? The problem is that I have never found any intact turtle on the road.
I would like to have some clean skeletons of representatives of⬠different classes of vertebrates for comparison, probably in the far future. But the dirty work is difficult.
The anti-roadkill picking laws in the US can almost always be easily bypassed by calling the Fish and Game Dept and having them come out and tag the animal for you. If you are a scientist or teacher, it's especially easy.
Really, though, if you don't get caught during the act of collecting the animal, no one cares that much. I don't think it's worthwhile to the state to pursue prosecution on the matter.
I currently have a medium-sized opossum in a large plastic tub and I'm hoping to use her skeletal remains for kids' workshops in the future.
Dermestids by mail!
http://wardsci.com/dermestid-beetle-assortment-living-specimen/p/IG0011…
http://wardsci.com/product.asp_Q_pn_E_IG0011615_A_name_E_Dermestid+Skel…
Nor, for pretty obvious reasons, will you.
Such skeletons are commercially available, but expensive.
What a shame that was! I'd sooner say you should ditch her than to give up such a collection. :(
@84:
I caution against using Ward's, they send only like 100-200... better deals are available on eBay, for example:
http://shop.ebay.com/ironraav/m.html
I have ordered from Ward's myself, and was not pleased with the amount received for the cost... on average, most sellers on eBay (mostly taxidermists) sell at the cost of 8-10 cents a beetle. The mark up on Ward's product (like most of their stuff) is incredibly high.
I have been using dermestids for the past half a year and been very pleased with the results. it's far better than boiling or maceration. Much cleaner, less foul smelling. :-o On top of that, the spoilage I've seen of bone material when using maceration or boiling is not appropriate for a bone collection. I've had no problem at all with beetles regarding these factors. I really think they're best.... :-P
In my current state of residence (West Virginia), there are no objections to picking up roadkill. Most of my mammal collection consists of those picked up from roadkill, particularly deer. :-)