A chorus of insects on the night air – it is one of those sounds that has lulled humans to sleep for millennia (in warmer latitudes anyway!). A nocturnal choir, singing us to rest.

But whilst it may seem to our ears like just a collection of bugs buzzing, a healthy nocturnal insect chorus is sonically complex, and shows evolution at work.

Insects choruses are among the most highly structured soundscapes on the planet. One of the best place to hear these rich and diverse symphonies is the dry savannahs of East Africa.

This is where we recorded our album; “An African Night“.

I would like to show you the structure of the insect symphony on this recording, because I find it fascinating. Here is a sonogram (a picture of the sound with time on the horizontal axis and frequency on the vertical) of a representative sequence.

You can see that nearly all the insect vocalisation fits into a band between 2kHz up to around 7kHz, with some other species intermittently calling higher, up to 20kHz at least. Within that primary 2-7kHz range, many species are vocalising simultaneously.

You can recognise clear bands. Each represents the voice of a particular species. By tailoring their vocalisations, each species has come to occupy a narrow frequency band. Its a bit like radio stations broadcasting on their own frequency.

Like radio stations, the reason insects do this is to be heard, and thus to survive.

In additional to frequency differentiation, some species employ temporal differentiation, where individual insects give shorter calls in antiphonal duets. To our ears, these are the ‘chirping’ or ‘chiming’ species, as opposed to the continuously zizzing ones. You can see this on the sonogram too. This strategy is similar to the way frogs vocalise, giving short calls with individuals alternating, sometimes creating complex polyrhythms.

These insect choruses are pervasive. They’re often loud and go all night (depending upon the locality and season). So it is interesting to see how other species in these habitats have developed calls that don’t waste vocal energy competing in that ‘occupied’ band of insect frequencies.

Large mammals – elephants, hyenas, impala, zebras – all call well below 2kHz, a factor of body size if nothing else. Elephants specialise in creating sounds of such low frequency that they are more felt than heard.

Diurnal birds often naturally sing in the same frequency range as nocturnal insects – but of course they don’t have to compete, they have a different time slot!

The night birds however, are different. Look at how the Slender-tailed Nightjar’s calls (a rapid chatter heard at around 30:12, and later, a quick series of calls on the wing at 39:34) are at a lower frequency range than the insects, not going higher than the lowest insect call. The Barn Owl (heard at 1:10:57) is similar.

Above the insects, the echo-locations of bats occupy the clear air of a frequency spectrum all their own. Occasionally they get a little interference from one or two very high frequency insects, which only call intermittently. Also a series of sharp ‘tick’s, which I think comes from a katydid, but may possibly come from a bat of a different species (although if it was a bat I think it would move around the stereo field with flight, which this doesn’t).

Tweet

Our timeframe at Ruaha NP was open, and we were not sure how long we would spend here. With just over two weeks left in Tanzania we didn’t want to waste our time in places that were not going to yield the results or experiences we were hoping for. After doing the rounds at the local markets and loading up with food and supplies in Iringa town, we made our way over the dusty and potholed roads to Ruaha National Park.

Our first impressions were promising, the Great Ruaha river was flowing, which was not the case just 3 weeks previously. The local authority has release water from the nearby dam – and where there is water there is life!

Elephants on the Great Ruaha River

After getting our park entry and accommodation permits sorted, we arrived at what was to be our home – a dining room with kitchen, shower block and toilets and small sleeping huts called ‘bandas’. These were metal in construction with straw roofs, not sure whether it was for aesthetics or insulation – but we were happy. I think all of us were more than relieved to be sleeping in anything other than our tents, especially with the wildlife wandering freely through the camp on a daily basis – elephants, hyenas, giraffe and a pride of 15 lions to name a few – exhilarating and terrifying (at times) to say the least!

Our banda, with giraffe!

The view from our camp dining area

Each morning would start with us waking at 4.20am, a careful scan for eye-shine, just to be sure that we could have our morning pee uninterrupted! Breakfast of porridge and tea, then all loaded up ready to leave by 6am for our morning safari!

Intense sunrise behind Boabab tree

After 5 days we decided to extend our time at Ruaha, the place had captivated us; the landscape itself was epic and vast and neither of us tired of its subtle beauty; in many ways it reminded us of the Australian outback. The diversity of bird life and wildlife exceeded our expectations, plus it felt like we had the place to ourselves.

In the northern national parks, like The Serengeti or Ngorongoro Crater, we had heard what to us seemed like horror stories: 80+ vehicles queued up to see lions or cheetahs. That might be fine if you only have 4 days to ’see’ these places, but a nightmare for us. I always remember the famous quote by Jean Paul Satre – ‘Hell is other people’ and that is true for us when it comes to sound recording!

Lioness and cub

Superb Starling

Oxpecker hitching a ride on a giraffe

Cheetah

On our last night at Ruaha, we stood outside the back of our banda as the moon was rising, taking time to reflect on our time at Ruaha and feeling sad to be leaving – it was our way of saying thank you and goodbye to our time in Tanzania. Over the rise came a herd of elephants making their way to the river, just 30 metres away. We witnessed the stateliness and dignity of the scene in front of us with awe. I had to pinch myself and Andrew to remember this moment.

Hear recordings from Ruaha national park on our new release ‘Safari’ – http://www.listeningearth.com/LE/product.php?id=101

Tweet

Each morning safari begins with an early start, so our album does too. This actual recording was made on one of our first mornings of field work – our initiation to wild Africa.

Star trails: The Southern Cross and Pointers hang over a baobab tree in the southern sky at dawn

I was standing in the darkness of predawn in the bush near Tarangire National Park. I had no idea of how safe it was for me to be doing this, considering the unknown wild animals that could be lurking in the dark. By my side however, was a Masai man, dressed in traditional red shawl, and leaning casually on a spear. He was my ‘escort’, and seemed pretty relaxed. Thus emboldened, I stood quietly, noticing the familiarity of the southern cross low in the southern sky, and the unfamiliarity of the sounds of this new continent.

The microphones were 20 meters away, recording the first birdsong of the day. Prominent were Spotted Morning Thrushes with their sweet and strong songs, a characteristic sound of the dry African bush.

Suddenly there was an animal call, the skittish cry of a zebra, and a few moments later the loud trumpeting and deep rumbling of an elephant. It was an electrifying moment. I remember thinking; Wow! This Really is Africa!

My escort leaned toward me, smiled and whispered: “Simba”. Swahili for lion. That’s what the animals were probably reacting to. I suddenly wasn’t feeling quite so bold! But we kept recording, and a few minutes later both a jackal and hyena began calling.

Of course this magical occasion has to open the album. If you listen closely, you can just discern the far distant roars of a lion in the opening minute.

Tarangire National Park is based around the Tarangire River, which threads its way through the savannah landscape, seasonally attracting staggering amounts of wildlife. We were fortunate to be there during the ‘Small Migration’ (the ‘Big Migration’ being at Serengeti). Massive herds of wildebeest and zebra were grazing out on the grasslands, and daily coming down to the river. Elephant were in abundance too, often seen in family groups – there must have been hundreds of these pachyderm clans in the park. And with the herbivores came the predators: lion, cheetah, hyena and jackal.

On this track you can hear the grunts of wildebeest; males defending their harem mostly, but there is also the mournful bleating of a calf among them.

By the time we made this recording, we’d realised the challenges of making good sound recordings in Africa. Getting microphones close to wildlife was problematic. Most of the time one couldn’t just stand there. Even getting out of a vehicle was not allowable in most National Parks.

This recording was made from our vehicle, with us all being extra still and quiet. On this occasion, it captured the sounds well, but as a recording strategy it had obvious limitations. We eventually developed a way of carefully placing the microphones out in the landscape as being the most productive way of recording in Africa (read more here).

The recording that makes up these 3 tracks shows how our ‘leave and see what happens’ approach could work wonderfully.

The microphones were placed on a tripod under a bush in a grove of acacia woodland. These woodlands were favoured habitat for herds of impala, and you can hear them rustling the grasses as the walk right by the microphones. Occasionally they give sharp alarm calls, or the males gruffly snort as they engage in fights for dominance with rivals.

The birdsong is rather beautiful, the mics being in a fortuitous sweet spot. Many of the calls are unknown to me, but a woodpecker is drumming noisily overhead, and there are boubous, bulbuls, lovebirds, doves, hornbills, spurfowl and a lot of very noisy dusky starlings.

A troupe of vervet monkeys were also moving around, and at one point an individual starts giving loud alarm calls close nearby. Soon the reason is revealed. A pride of lions begin calling nearby. Rather close nearby!

Lions usually rest during the day, but in the early morning, prides can occasionally be heard roaring like this. We had the privilege of experiencing them do this at close range. Adults make sounds with their whole body, their breath condensing in the morning air. It is a huge sound, intimidating, and the first time we heard them roaring up close, it took our breath away!

There are areas in the African savannah where, for kilometres around, every bush is decorated with the nests of grey-capped social weavers. The number of birds in a single colony may number many thousands.

This recording comes from one such area, with the mics placed in their midst as the birds feed, call and flit past the microphones. The sense of movement is exhilarating.

Elephants love water. And mud. It was such a delight to see them each day enjoying both.

Family groups would take turns at the waterhole; walking in from the surrounding grasslands, splashing into the water, sloshing the muddy mix over themselves, and then moving to a favoured and obviously oft-used tree for a good, all-body rub and scratch.

Here you can listen to them indulging in all of the above!

It is a surprise to many visitors to Africa to find not only that zebras are so vocal, but that they sound so much like… donkeys! We’ve been told that zebra in swahili literally means ’striped donkey’.

In this track you hear a group coming to water. They seemed especially wary of predators, and we got a sense that their calling reflected a nervous temperament when they felt exposed.

In the foreground are the wheezy, tinkling calls of white-headed buffalo weavers.

Wildebeest en masse and on the move. Here a huge herd come down to the river, drinking, and crossing to the other side.

This recording seems to be everyone’s favourite. We have played it to numerous friends and always enjoy witnessing their surprise, delight and amusement at the sounds of these creatures. Hippos sound amazing, and we got a good close recording.

However it was made with significant apprehension. Hippos are regarded by many as the most dangerous animal in Africa. They are unpredictable, aggressive when threatened, and move with surprising speed when they want to.

So when we set up camp on the banks of the Katavi River in far western Tanzania, we were a little alarmed to find we were sharing it with around 200 hippos who spent their day only 100 meters away, lazing in the fetid water. During the heat of the day, they are rather placid, but as the afternoon cools down they become more active, eventually emerging from the river after dark to graze on surrounding grasslands and river banks.

We had a wooden fence around our camp, but it had been trampled in a few places, and wasn’t going to stop anything the size of a hippo. So each evening, with our flimsy nylon tents clustered protectively around our vehicle, we would lie listening to the sound of heavy footfalls and grass being chomped around us, all accompanied by the bellowing and roaring of these cantankerous animals. We didn’t get much sleep for a week!

Our campsite at Katavi. On the far right side Andrew (in a white shirt) can just be seen standing beyond the wooden fence, on the riverbank above the hippo pool. That is how close they were to our tents!

But we did get this recording. It was made later in the afternoon, with the microphones placed on the riverbank overlooking the water and its huge, wallowing inhabitants. You can hear them calling in chorus, snorting, and the cute sounds of them twitching their ears. At one point you can even hear one defecating, a distinctive sound as they flick their tiny tails side to side, thus desiccating and spreading their fibrous excreta.

Just when we thought that we were crazy enough sleeping by the Katavi River, we heard something else. Our driver, Roger, alerted us to it the first night: “Andrew, did you hear that? Leopard.” It was a low, huffing series of growls and it came from a small gully running into the main river. The following night I saw the animal, or at least its eyes shining in my torchlight. It was coming down to drink each evening.

Leopards are notorious stealth hunters. Oh great. Another reason to be especially alert and not stray far after dark.

This recording captures some of the night sounds of the African bush. In particular the cries of bush babies as they move around the tree canopy, and loud alarm calls from a troupe of baboons. You can hear the leopard on this recording (0.14 & 3.09, actually two of them, one further away; 1.39). Oh, and a gruff, single growl from a lion (2.37). No wonder the baboons were also getting a sleepless night!

If you listen closely to the final minute of the recording, you can hear a flight of large birds mysteriously winging their way high overhead (5.17-6.15); water birds? ibis maybe?

Recording those hippos in the afternoon at Katavi

Africa was a truly amazing experience of us. Our best field trip ever. We hope you enjoy taking your ears on safari as much as we did!

Tweet

For me as a nature sound recordist, they posed both an opportunity and a huge problem. How was I going to record them? How could I record anything else with them lurking around?

This field trip was our first experience of Africa, and we had no idea of what to expect. We had booked a vehicle for 7 weeks, and with it a driver and a cook. Roger and Ally turned out to be the best of companions; capable, knowledgeable and always filling our days with humour. Indeed, we laughed our way around Tanzania. (An early priority was to name our little safari, and after some banter, we settled on The Mwongo Mwongo Safari, which in swahili means; small talk, inane chattering, shooting the breeze or as we’d say in Australia, just talking bullshit! Perfect.)

The Mwongo Mwongo Safari on location at Katavi: Andrew, Allly, Sarah & Roger.
And yes, those are hippos behind us, the ones you hear on track 10 of our ‘Safari’ album.

Before we left for Africa, we anticipated that we would spend some time viewing big game, enjoying the novelty, and then leave the grunts and bellows to get down to the more rewarding business of recording the more aesthetic birdsong.

How wrong we were. The animal sounds are the highlight of the African soundscape.

We first realised this when we arrived at Tarangire, where the ’small migration’ (Serengeti being the big migration) was in full swing. The Tarangire River was attracting huge herds of wildebeest and zebra; tens of thousands of them were grazing in the open grasslands and coming daily to the river. Hundreds of individual families of elephants wandered around, and we’d be coming across groups every day. And with the herds, came the predators; lions, cheetahs, hyena, jackals.

The problem was how to record these animals.

It is not feasible, safe, or even allowed, to get down from a vehicle in many of Tanzania’s big game parks. After mixed results recording from our vehicle, we realised we needed another approach, one that would allow us to get more intimate recordings.

I began thinking in terms of leaving the microphones out in the landscape, to record ambiently for long periods in the hope of getting something fortuitous.

This strategy was prompted by a happy discovery. Before the trip, Sarah had hesitantly purchased some no-name batteries online. When I tested them, I found they ran our SD722 digital recorder for twice the time that the Sony-branded batteries did – I was getting 10 and a half hours from a single battery! This transformed everything. I could now leave the microphones on a tripod to record overnight, when wildlife was most active.

For those interested; my no-name battery. This is all that is printed on it, no branding.

However, I was concerned that my microphones were taking a life-threatening risk. They could be trampled, or dragged off somewhere by hyenas. I was always anxious when returning to retrieve them, but fortunately, they survived. Their worst misadventure was a close, sniffing inspection by a pair of Aardvarks who knocked the tripod over.

However on another occasion, our gear had a lucky escape. Collecting it from under a bush after an overnight session, I noticed elephant prints in the dust right next to the microphones. Listening back at camp, we found we’d recorded a scary encounter; the footfalls of an elephant approaching steadily, the animal eventually standing right over the mics, breathing heavily, before moving off after a pride of lions began roaring only about 50 metres away. Phew!

These listening sessions at camp were a revelation. Roger would often join me, and with great expectation we’d scan through multi-hour audio files (using Izotope RX sonogram on a MacBook Pro) for the ‘interesting bits’. His ability to identify the strange sounds of the African night was invaluable. To my novice ears, hippos roaring were easy to confuse with lions, and I would have guessed our unexpected recording of leopard was just a baboon grunting.

The distinctive sonogram pattern of a hyena calling at night

Sitting out in the bush, our SD722 recorder would be writing to a compact flash card, to save battery life. Back at camp, the files would be backed up on HD, and by the end of the trip we had nearly 300Gb of audio data. That is a lot of listening for us to go through back in the studio!

Sometimes we’d record whole evenings with not much happening, or morning into afternoon where all the birdsong seemed to be happening somewhere in the distance. But as often as not, we found we had recorded something extraordinary.

Some of these highlight recordings have found their way onto our ‘Safari’ album. Others are awaiting forthcoming projects, such as an album of African night sounds. In the meantime, here is some of ‘Safari’ for you to sample, and you can download the complete album here:

Tweet

The unmistakable profile of a Common Hoopoe. I love these birds, with their distinctive thin bill and counterbalancing crest. I think they have evolved just to delight me! (Mind you, I could say that about most critters)

Thick-billed Flowerpecker (trying to make itself more colorful by surrounding itself with flowers). Somehow gratifying to see this little bird feeding on mistletoe, which is a common parasite on eucalypts in Australia. The light was very harsh at midday, so I was lucky to get it in the shade.

Oriental Magpie Robin, every Indian garden has one (or two). Taken in the garden outside our hotel this morning in soft morning light.

Gulp! Indian Grey Hornbill feasting on figs. These big birds have are usually very flighty, and difficult to get close to. You just have to catch one when it is distracted, and what better way than with FOOD!!

Shades of sky blue; The Indian Roller.

Diminutive Jungle Prinia singing in the shade of midday.

Tweet

Coppersmith Barbet feasts on figs. I am so delighted to share this photo. I have always been hoping for a good shot of this bird. Firstly, they are little jewels, secondly they are quite common and vocal, so they’re heard on many of our Indian albums. This image comes from our walk today, when we came across a tree in the grounds of a temple with about a dozen Barbets gorging on the fruit.

A pair of Green Bee-eaters at their vantage perch. The delicate trilling, tinkling calls of Bee-eaters are unique and delightful. This pair were just happy to sit and call every now and then.

A male Indian Robin contemplating his garden. Australia has its Robins, Europe does too, and America… this is what the Indian species looks like. There seem to be a pair in every Indian garden. A lovely bird and quite confiding, difficult to photograph because of the dark plumage, but the dappled light here shows him nicely.

Oriental White-eye plays peek-a-boo. These little birds are so quick! This little fellow stopped eating for just long enough!

Common Hawk Cuckoo in the dappled light of the forest.

A Common Tailorbird hides among the foliage. Sometimes, a bird will get itself right into the heart of shrub, and from every angle you try, the bird shifts slightly to hide itself. Just managed to get this quite atmospheric image from less than a meter away.

Tweet

Here we go! – week 1.

Three Plain Prinias cuddle up in the morning sunlight.

Irridescent – the male Purple Sunbird.

Red-vented Bulbul, its beautiful bubbling song is heard in many of India’s gardens. Bulbuls are a common species, but I’m very fond of them, and this is a nice shot with the flowers out of focus behind.

A Black Drongo scans the forest, making aerial forays out to chase insects. I love the little white dot at the base of the bill, characteristic of this species. Their fish tails are also distinctive, and they are easily recognisable as they sit upright on branches looking for their next beakful.

Jungle Babblers after indulging in a mutual preening session. Jungle Babbs are very social birds, often mobbing noisily through the forest in groups of a dozen or more. This pair had just finished preening each other, involving some very fluffed feathers!

Brown Rock Chat, nonchalantly perched on a 2000 year old pillar at Sanchi. We’ve encountered these confiding little birds at many of the archaeological sites we’ve visited recently in central India. Old monuments seem to make great vantage points to look for a tasty morsel. Maybe they are the guardians of these heritage sites!

Yellow-eyed Babbler peers out from among marigolds. What I LOVE about this image, is the way the bird’s yellow eye wattle matches the marigolds.

Tweet

Among the mogul ruins of the ancient Indian town of Orchha, are the huge Raja and Jahangir Mahals, the Chaturbhuj Temple and a collection of impressive chhatris (cenotaphs) on the banks of the River Betwa.

Atop the rooftops of these decaying buildings roost a colony of Indian Vultures. They are huge birds, but we didn’t notice them at first as they blend into the baroque ornament of the spires and parapets. However when they spread their wings and take to the air, they cast shadows on the ground, and looking up… well, they are magnificent. When they alight again, they look so much a part of the roofline – medieval gargoyles, stern against the sky.

Sadly, Indian Vultures have suffered huge population declines – around 98% – in recent years, due to the widespread use of a cattle drug which persists in carcasses and causes kidney failure in vultures. The Govt has banned the drug as of 2010, but it is still being used and it will take a while before it is replaced. And many more years before populations of this long-lived bird may recover.

Critically endangered – The majestic Indian Vulture.

Tweet

Family of Barn Owls just after dusk – adult on the right, the curious ones are the youngsters!

Before I got the opportunity – actually the next morning – walking across the courtyard, we were beckoned over to see something. A group of young men had one of the juvenile owls tethered by a cord; they must have caught it feeding.

India often presents injustices which foreigners find difficult to respond to, and we’ve come to appreciate that it is usually better to stay sanguine, rather than get angry and self-righteous in someone else’s country. But there was something about this lovely bird, ruffled, tethered, and blinking in the sharp sunlight, and the youth looking for a few tourist rupees to view his prize.

“Why do you do this?” I said sharply. Everyone looked shocked, this was not the response they’d been expecting. I could see they didn’t know much English, and I was communicating more by body language. I indicated they should untie the bird and let it fly.

Fortunately, the groundsman, who picked up some extra income guiding tourists, was keen to keep me happy, and gestured to let the bird go. The cord was untied, but the bird just sat. Maybe it was injured, so I took off my jacket to put over it while I checked for anything obvious. But the owl was fine, and dodging my jacket, took wing and flew off toward its roost.

Two juvenile Barn Owls perched under an ancient mogul gateway in Orchha, India – awaiting mum’s return with a mousy titbit, no doubt.

In retrospect, I’m glad I took action. It was spontaneous and genuine. Explaining the value of wild animals would have been pointless, but demonstrating that there were no rupees in displaying a captive creature I hope sent a more pertinent message.

That evening, I went down to the gateway at 6pm. Three owls were perched, two screeching, which I presume were juveniles with an adult.

Happy hunting!

Tweet

Nagzira Wildlife Reserve protects a forested and hilly area in central India where Tigers still roam, and the woodlands are filled with birdsong.

First light across Nagzira Lake.

In the centre of Nagzira forest is a lake, and on the far side, a pair of Grey-headed Fish Eagles roost.

On this recording, made around 5.30am, you’ll hear their morning wake up and pair bonding calling. Dew falls from the leaves of nearby trees, a last chorus of Spotted Owlets is heard before the day begins, fruit bats flutter close to microphone, and the cries of a Lapwing echo from the far end of the lake.

I’ve included a spoken introduction to this recording.

(Thanks to our friend Girish Vaze for his wonderful image of the Fish Eagle.)

Tweet