The sweet smell of petrichor

BLX vs thunder storm

A week ago in Tsavo, we had an unseasonal storm of rain. We’d been flying, doors off, searching for the matriarch that we’d not seen for a while. As the cloud thickened and lowered, and dark skeins of rain descended to hide Musinga Hill, we headed back towards the airstrip, lest we get rained out. We landed with minutes to spare. We’d just got the camera off and doors on before the first violent gust arrived that whipped the rudder over, and set the plane rocking on it’s under-carriage. Neither of us cared that the search had been cut short though, because with the wind came the smell of rain – the sweet smell of petrichor.

Everyone has their own favourite smell – it might be that of new-cut grass, the bruised leaves of lemon verbena, freesia flowers or linseed oil.

For anyone that has lived in rural Africa, the smell of petrichor is likely to be high on the list. I didn’t know the word existed until a year or two ago, when it was mentioned by a geologist friend. For such an evocative smell, the word has a hard, scientific edge to it – as if wrought from decades of lab work, academic etymology and too little time spent outside, with a smile tilted up to the rain.

Perhaps unsurprisingly, the term was coined by two Australian scientists from the greek words petrus (rock) and ichor (the fluid flowing through the veins of the gods). I might not like the word, but I do like what it describes: rain soaking into the soil, freeing botanical molecules that have been trapped by clay and rock – volatile essential oils that rise to the surface and are carried on the wind that rolls out across the ground from thunderstorms. It is why we couldn’t smell it from the air – petrichor is for earthlings.

For me, the smell conjures up images of vast Serengeti landscapes, where wind-lashed grass heads are topped by churning skies. I like to think of cold petrichor-laden air sinking into termite mounds, and waking winged alates. It rarely disappoints. Elephants turn their trunks towards the source minutes before the cold wind arrives – that stirs and then bends their ragged ears. Impala and gazelle hunch, backs to wind. Ostrich crouch low to the ground. Out on an exposed branch a grey tree frog shifts its position almost imperceptibly – the first move it has made in months. Then the first fat drops fall, and spatter on the backs of Tsavo elephants. Rivulets flood their wrinkled skin, before pooling, ochre at their feet – leaving them fresh transformed, grey once again.

Skeins of rain

Smell is so important in the bush – I remember locating our first pack of hunting dogs, the legendary ‘painted wolves’, by following an unfamiliar smell – a sharp, acidic smell of sweat laced with musk that we’d caught while driving past a hidden erosion terrace in Serengeti’s Gol mountains. It led us to their den.

‘Follow your nose’ is still a common expression but most of us live in a world so noisy and confused with manufactured smells that it is difficult. We spray them around where we live, lather them on us, seep our vehicles in them, wash our clothes in them, and enhance them in what we eat and drink. Subtle smells are swamped . I pity a lilly-of-the valley in a room full of ‘Rozee’ air ‘freshener’.

To really follow a scent you have to move in and out of the odour plume at an angle to it. To find a fresh pile of elephant dung, airborne dung beetles home in on the odour by following a zig-zag flight path against a concentration gradient, turning more frequently as they approach the source.

I did the same recently with a colleague, Etienne, in the Arubo Sokoke forest.  We’d gone looking for frogs but found the waterholes were dry.  We’d not walked far, when Etienne caught the faintest scent of a carcass. We walked slowly upwind a hundred meters apart, quartering – calling to each other, now and again, as the smell got stronger or we lost it completely, and had to double back. After half an hour and almost a mile we arrived at a horrifying scene – a baby elephant had been caught in a wire snare. It had been butchered – its meat, cut into strips, hung from drying racks suspended from branches, out of reach of scavengers. The maggot-ridden entrails were the source of the smell. The skull, skinned and abandoned in the dirt, had  two tiny holes where the finger-sized tusks had been removed.

It was distressing; more so when we saw the acacia that the snare had been fixed to – the wire had sawn an inch or more deep into the trunk as the baby had struggled. It had taken hours, possibly days to do that, and the baby had quite likely still been alive when the poachers returned.

In Tsavo, poachers have learned to cover the carcasses of elephants with brush, so they can’t be seen from the air – by vultures (which might attract the attention of rangers) or pilots.  A pilot flying anti-poaching patrols told me recently that he flies low and slow, with his windows open, so he might catch the smell of a poacher’s cooking fire or the scent of putrefaction.

It set me thinking why we find the smell of putrefaction almost universally abhorrent. In the course of human evolution, to be able to recognize the smell of rotten flesh must have conferred a strong selective advantage. It still does. We recoil at a strong ‘fishy’ smell – and that helps us avoid food poisoning. What we take to be the smell of fish though is actually the smell of rotting fish. It emanates from the formation of amine chemicals given off by bacteria breaking down protein, as they rot fish flesh.  ‘Follow your nose’ is just as good advice when it comes to sourcing fresh fish. Interestingly, citric acid in lemon juice neutralizes alkaline amines and reduces the ‘fishy’ smell – its use with fish may have originated as a way of concealing the smell of rot.  I might be biased but I think live fish smell glorious – and very different from each other. I can easily distinguish mackerel from mullet, and pollock from bass in the same way that I can smell the difference between oranges and lemons.

What I find fascinating, is the powerful ability smell has to unlock distant memories. It is almost as if it can bypass the rational, left side of the brain altogether.

In the course of filming, we spend a lot of time around elephants and we smell elephant dung almost every day. It is a familiar smell and not offensive – it is redolent of the farmyard with an almost silage-like sweetness to it. It is quite different from the pungent, protein-sticky odour of a carnivore’s dung.

On two occasions though, when I was thinking about something completely different, I have smelt elephant dung and it has conjured up a powerful and distant memory – transporting me back instantly to being a small boy on a wet winter’s day, snug in a green quilted anorak, holding onto my mother’s hand. The place was Bristol zoo. I was four, giddy with excitement from a day trip up from Cornwall, and wide-eyed with wonder at all the different animals I’d seen.

What I remember most though and what my recollection of that entire day is based on, is how, long before we saw the elephant – I smelt it.

BLX in rain



© Mark Deeble and A Wildlife Filmmaker in Africa, 2014. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Mark Deeble and A Wildlife Filmmaker in Africa with appropriate and specific direction to the original content.

About Mark Deeble

A wildlife filmmaker in Kenya. My home is in Cornwall. My heart is in Africa. I have a tent in Tsavo. I share it all with Vicky. We are working with an amazing team, making a wildlife feature film -
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37 Responses to The sweet smell of petrichor

  1. Sam says:

    Very timely… We have just had a shower of rain go through the garden releasing the petrichor… Utterly wonderful… followed by the steam bath… less wonderful. Thanks Mark

  2. David Dance says:

    Wonderfully evocative as ever Mark, but how do you explain the fact that in some parts of SE Asia people love the smell of pa daek ( which is fermented’ (aka rotten as far as my nose is concerned!) fish sauce, and add it to almost any food? Unfortunately, unless fully mature (> 6 months old) this comes with a high risk of transmitting human parasites such as oriental liver fluke ( Apparently one of the problems of modernisation in this part of the world is that people are now more likely to buy their pa dark rather than make it themselves, meaning that they have less control over how long it has been fermented.

    To fully appreciate the aroma you will have to come to visit us here in Laos!



    From: Mark Deeble <> Reply-To: Mark Deeble <> Date: Sunday, 9 March 2014 12:57 To: David Dance <> Subject: [New post] The sweet smell of petrichor

    Mark Deeble posted: ” A week ago in Tsavo, we had an unseasonal storm of rain. Wed been flying, doors off, searching for the matriarch that wed not seen for a while. As the cloud thickened and lowered, and dark skeins of rain descended to hide Musinga Hill, we headed bac”

    • Mark Deeble says:

      David, I imagine the appreciation of padaek represents a triumph of nurture over nature that spans many generations! I guess the fermentation process preserves it and maybe the ‘falang’ olfactory senses can’t differentiate fermented fish from rotten fish – perhaps it is all in the quality of the amines. I look forward to a visit to taste it ( I think!).

  3. marvalus2013 says:

    Fascinating article especially as I have, to some degree, lost my sense of smell and I really miss the feelings that come automatically with certain smells. Strangely, I can smell nasty stuff more than sweet aromas from flowers or perfumes, so I suppose at least I can tell when something is off.

  4. U write so beautifully mark – its sunday morning here, I am sat here with a coffee enjoying my brief journey to africa and the evocative picture you paint! s x

  5. Richard Morris says:

    Another brilliant piece, Mark, with one huge omission…the bouquet of wine! I can (on a good day) tell a cabernet-sauvignon from a merlot, just as you can a mackerel from a sea-bass, at 100 yards)…we’re looking forward to seeing Jacca next weekend – Rich

  6. Hamish says:

    Is that how the herds move, the smell of petrichor guiding them to rains beyond the horizon?

    • Mark Deeble says:

      I suspect it is important as they can probably detect it at far lower concentrations than we can. The infrasound associated with thunder, and flashes of lightning at night probably also play a part.

  7. Beautifully written, Mark. Since my senior year in high school, when I wrote a paper on Kenyan Wildlife, I’ve wanted to go to Africa. That was Nearly 50 years ago and time is running out…
    I often feel “blessed” to make even a moderate living doing what we do because of the moments and rush of life which you describe so well.
    Capturing and conveying those moments are what give me hope. In fact it may be the only thing which gives me hope. The great cycles of life and nature are being pushed by we humans like never before.

  8. arzokappa says:

    i love this post.. I love the smell of rain, which of course is not the rain itself.. as you so eloquently explained.. I never thought that fish could smell distinctly differently, but now will start to finally notice that… I happen to love fish sauce so that smell is not so bad to me, btw… and yes, that a scent, just like a song, can evoke memory to a specific time and place, its such a powerful sensation and a great gift.

  9. Jack Couffer says:

    Mark. Im greatly enjoying your posts. Keep em coming. One comment on this one. There is a bit of research on American vultures (buzzards, we call them) that tells us they rely on smell to locate prey. The first I know of was at least 30 years ago when ornithologist Kenneth Stager discovered this and wrote a paper about it. There has been recent corroborating literature about this fact.

  10. lief says:

    your words talk so much of your love of Africa, and the gifts it has shared with you… thank you…. It gives me such evocative memories of the brief
    moment I shared with you and Vic, and my childhood.

  11. Another fantastic piece Mark, thank you!!

  12. Lynne Richardson says:

    As the breeze lifts, the smell of rain, the lull and the beautiful sound of those ‘fat’ drops on the earth – you reminded me of some of those perfect moments. Thanks Mark!

  13. Andrew Wyatt says:

    Reblogged this on The Last Word and commented:
    “I love the smell of petrichor in the morning– smells like… Africa!” ~Andrew Wyatt

  14. Dave Dickie says:

    Hi Mark, Beautiful and very evocative writing! I have worked with both Simon Trevor the film maker and David Shepherd the artist who both had footage shot in Tsavo in the 60’s. The images were incredible…elephants as far as the eye could see covered in that red Tsavo dust….almost surreal especially against those stormy African skies! So sad that we will probably never see scenes like that again.
    Keep up the good work… it! Dave

  15. Lynn Wilson says:

    What a fantastic post Mark. I am new to your blog, but am so happy to have found it. Your gift with words evokes images and feelings about Africa that I have never known first-hand, and maybe never will. That being said, I am transported to Africa through your verse, and thank you for that experience. I am so saddened about the horrible fate of the panicked baby elephant.

  16. Beautiful post Mark! I could smell the smells from you words! In India we call earth or mud “mitti” with a sharp emphasized t like in totter. And I had piece found a perfume that smelt of the earth just before it rains. It was a very unstable aroma which faded into something close to sandalwood. But that very instability made it authentic … Once the rains come the perfume dissipates … And a memory lingers …

  17. Amlakyaran says:

    very nice post… thanks

  18. Interesting read. I had never heard of petrichor until today!

  19. jorvadorie says:

    Reblogged this on Jorvadorie's Blog.

  20. I really enjoyed your post, both for the knowledge it conveyed, and your poetic way of sharing it. Thanks!

  21. cathie2014 says:

    One of my Y10 students taught the word ‘petrichor’ to the rest of the class recently to help improve their vocabulary, which is why your post caught my eye and I really enjoyed reading it.

  22. I could enjoy the smell with you almost… although I have never ‘met’ petrichor, I also love one of those smells released by the rain – creosote bush. Without rain, the scent is only detectible close up, but I often when returning home from a trip, will stick my nose in the creosote bush outside the gate before going in.

  23. herschelian says:

    Petrichor – one of my FAVOURITE words ever, and the smell…fantastic. I grew up in Zambia, and the smell of the rain on the hot earth is incredibly evocative of Africa for me. Thanks for a great post.

  24. jeritilley says:

    Always wondered what that smell that comes with the first rain after a long dry spell was called, now we know!

    And flying with the doors off is THE way to go!

  25. Tish Farrell says:

    Mmm, the smell of the rains on Kenya’s rich, red earth. And then the termites bursting forth on their brief nuptial flight, and the litter of wings in the red mud when the deed is done. There is also the musky sweet smell of fever tree bark, and the crushed mint smell of escaped Mexican marigolds on the Kikuyu farms. In fact, you’ve reminded me that I’ve suffered complete olfactory deprivation since I left that beautiful country. I even quite liked the smell of Nairobi’s open drains, but that’s probably a bit weird.

  26. This post was a pleasant surprise, even though it devotes a significant amount of attention to the smell of poops and rotting flesh. I initially thought petrichor was some kind of petroleum based fuel source and you were hot on the trail of some “black gold.”

  27. worzelodd says:

    Lovely post thanks, I biked every where as a callow youth, to see the sees and smell the smells, ride a bike. Know a prairie farmer addicted to the scent of fresh turned earth. I worked in a bakery, but could not smell over time the bread and sweets baking, olofactory overload perhaps.

  28. Pete Buckley says:

    A great read though I was much saddened by the story of the elephant – how can people do that? This post captures my perception of the Africa I would like to visit.

  29. kkessler833 says:

    Thank you for the great post!

  30. these images are absolutely stunning

  31. ianbcross says:

    Everyday when I cross the Luangwa River bridge going to work at Kakumbi rural health centre, I smell a sickly scent which immediately reminds me of the awful, thick, pink protein drink I was given as a four year old patient in a burns unit. I’ve no idea what it is.
    Petrichor is an impressive word for a wonderful, welcome aroma, signifying the dry season is ending. Sometimes you can smell it after just a few big blobs of rain.
    A special post, it certainly struck a chord with me.

  32. Jai says:

    Beautiful, Beautiful post….I found myself nodding emphatically at several stages, at your evocative writing! The smell of rain—aah, that lovely, intoxicating smell–your very words took me back to my childhood and teen years, of running out to get soaked in the rain, dancing in the puddles! I should try that again soon. Loved your imagery of elephants coated in red Tsavo dust being washed back to their fresh, natural gray–I hope to be lucky enough to see that, one day. My last experience seeing wild elephants was in April, in a National Park in South India. Saw a small herd of 2 adult females, a sub adult and a tiny calf. The baby had stumbled into a shallow ditch by the side of the forest road, it was amazing to see the elders helping it out so solicitously.

    I love the smell of elephants too– I visit my ancestral home in a small village every year for a festival at the local temple, which has a procession of caparisoned tame tuskers. I love to give them bunches of bananas in their trunks, or occasionally right into their mouths! There is a certain musky odor around them which is certainly not unpleasant.

    The local fable had it, by the way, that if one were to step barefoot on freshly shed elephant dung, one’s hair would grow long and lustrous ! Not sure if that’s true–but certainly the dried up dung had a certain farm-like, almost herbaceous odor to it.

    Now that I am older, I do feel a pang at the long hours the temple elephants have to stand and walk in the sun, and am somewhat ambivalent about their role. But the years of fascination seeing them as a child, are difficult to quell.

  33. Jai says:

    Mark, just to add to my comment above–other powerful memories your writing brought back, were the 2 sightings I had about 4 and 10 years ago, in different National parks here, of elephant herds crossing a river. They plunged in, brown and dusty, trunks reaching out over the water like snorkels, and emerged gleaming black on the other side! The mothers appeared to be first encouraging their calves to take the plunge, and then supporting the smallest ones from underwater–its moments like these, that one realizes elephants have a society all their own, they are thinking, feeling beings that humans have absolutely no right to maim, kill or drive out of their habitats.

    Very sad to read in your article, about the agony the calf must have gone through at the hands of the poachers. One really hopes the perpetrators were caught and faced stiff sentences–but sadly, I think it’s more likely they escaped. Still, all is not lost yet, if we act now, we can still salvage what precious little remains. News has come in today in India, of 2 poachers being gunned down during an armed battle with forest guards in the Kaziranga National park. Hope this sends a strong message out to poachers–that if they live by the gun, they have to die by it, too.

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