Hippo aggression

This is the second post of four I am publishing from our recent five-day trip with CNP on the Chobe River. As many of you who have been to the Chobe know, there are plenty of hippos (or river horses as the ancient Greek’s called them) in the river, some relaxed and some not so relaxed.

There are two types of hippo found in Africa. The small one is the pygmy hippo which is found to very restricted ranges in West Africa. It is a shy, solitary forest dweller and is rare. The other is the ubiquitous large common hippo.

Nature, hating art and pains

Baulks and baffles plotting brains;

Causality and Surprise

Are the apples of her eyes.

 – Ralph Waldo Emerson
Nature, hating art and pains,Baulks and baffles plotting brains;Casualty and SurpriseAre the apples of her eyes.

RALPH WALDO EMERSON, Nature I

Read more at http://www.notable-quotes.com/n/nature_quotes.html#dKH2gJb6KM6I1MGl.99

Nature, hating art and pains,Baulks and baffles plotting brains;Casualty and SurpriseAre the apples of her eyes.

RALPH WALDO EMERSON, Nature I

Read more at http://www.notable-quotes.com/n/nature_quotes.html#dKH2gJb6KM6I1MGl.99

Common hippos are known for their aggression and are the animal which kills the most people in Africa each year. The large hippo is an aggressive animal etched with old scars and fresh, deep wounds both signs of daily fights. These daily tangles are usually accompanied by much bellowing, neighing and snorting. An agitated hippo makes a sound like the air-brake exhaust of a 20 tonne Oshkosh truck when it is going down a hill. Hippos have developed some ritualized postures, the most intimidating of which is the huge open-mouthed “yawn” revealing their formidable teeth. With the long, razor-sharp incisors and tusk-like canines, the hippo is well-armed and dangerous. We did not have close calls this trip thanks to the guides knowledge of the river and the hippos. The territorial bulls are apt to show you, not very subtly, that you are in the wrong place and best you should scram. I think that open-mouthed signal is fairly convincing.

Chobe river wildlife photography

Chobe river wildlife photography

For a wildlife photographer, hippos can be awesome subjects but they tend to rest during the day so are usually not very active. That said the bulls are always looking after their territory and harem. Also nature always throws up surprises.

Chobe river wildlife photography

Chobe river wildlife photography

Bull hippos can weigh over 3 tonnes and are able to move through waist deep water surprisingly fast. On land, a hippo can reach 30km per hour despite its bulk. A cameo of experience – I learnt a lesson, first hand, paddling a canoe down the lower Zambesi beyond Ruckomechi. Unintentionally we cut a hippo off from the deeper water and it charged us. The speed of the charge shocked us. The adrenaline kicked in and even Yamaha or Evinrude would have been impressed with our turn of speed in the canoe. We managed to get out-of-the-way unharmed  but shaken. Despite being semi-aquatic and having webbed feet, hippos do not swim in very deep water but rather propel themselves by bouncing off the river bed. We discovered this characteristic one morning on one of CNP’s boats when a bull charged from the side of the river. We moved into the centre of the river which was very deep and thought that was the end of the charge. To my utter surprise, the hippo kept coming even in that deep channel just passed the army camp as you enter the Chobe National Park. This is one animal I have learnt not to under-estimate.

As with most young animals they play while the adults are trying to rest. The next four images of two youngsters, one quite a bit bigger than the other play fighting.

Chobe river wildlife photography

The play fighting seems harmless as they have not developed those killer teeth yet.  The hippos teeth grow all of their lives and are self sharpening as they grind together. The lower incisors can grow to 40cm and canines to 50cm. Hippos do not use these tusk-like teeth for eating but rather protection and attack. Hippos use their molars to grind down the vegetation they eat. Their broad hairy lips are used to grip and pull out grass and aquatic vegetation.

Chobe river wildlife photographyChobe river wildlife photographyChobe river wildlife photography

Gie me ae spark o’ Nature’s fire.

That’s a’ the learning I desire.

 – Robert Burns

On the third afternoon of our Chobe trip, we travelled passed Elephant Alley, beyond the Chobe Game Lodge down to Puku Flats. We usually get good sightings of Fish Eagles there. This particular afternoon we saw a female hippo out of the water around 16h00. She was standing over something so we went into one of the nearby channels to have a closer look.

Newly born hippos are relatively small, weighing from 25 to 55 kilograms, and are protected by their mothers, not only from crocodiles and lions but from male hippos which, for some reason, do not bother them on land but attack them in water.

To our dismay, the female hippo was standing over what looked to be her dead calf. We assumed it was dead because it was motionless despite the female nuzzling it and resting her chin on its body.  The calf was lying on its side in the grass close to the water’s edge. 

Chobe river wildlife photography

The hairs on the lip of the hippo look to be highly sensitive and it appears that this female was assessing her calf by touch.

Chobe river wildlife photography

The next image is as close to distress as I have ever seen in a hippo.

Chobe river wildlife photography

This female turned to face us and opened her mouth as a threat even though we were nowhere near. There was a group of nine Yellow-billed Oxpeckers on her back cleaning up all the cuts in her hide. Red-billed Oxpeckers are much more common, so it was quite unusual to this flock of Yellow-billed Oxpeckers. The hippo has little hair and its skin is around 15cm thick. Hippos lack scent and sweat glands. Instead, mucous glands secrete a thick oily layer of red pigmented fluid nicknamed “blood sweat.” It is now known that this fluid is a combination of hipposudoric and norhipposudoric acids. These compounds create a sunscreen effect by absorbing ultra violet rays from the sun and prevent the growth of disease-causing bacteria. The secretion originates colourless and turns an orange-red within minutes of being exposed to the sun.

Chobe river wildlife photography

After watching the scene for some time, it became clear the calf was dead. There was no way of telling how it died. It looked very young. It could have been killed by a territorial bull hippo or some predator the night before as it had a big gash on its flank. The next image shows how protective the mother was and every time the bull tried to get close she would give a stern warning to back off, which he did that afternoon.

Chobe river wildlife photography

The next morning, first thing, we went back to the scene of the dead hippo calf. Now the bull was out of the water and nuzzling the calf and the female still appeared to be very distressed This is one situation where you do not want to get too close. Sexual dimorphism is present in hippos. Males tend to be about 200 kg larger than females at maturity, but can grow to be a few thousand kg larger with age. Males appear to continue growing throughout their life, while females reach their maximum weight around age 25.

Chobe river wildlife photography

We were not sure what the bull was doing to the calf but he was not feeding or damaging it in any way. The Fish Eagle looked like a conspicuous opportunist.

Chobe river wildlife photography

We watched for over an hour but little happened so we decided to return that afternoon to check if there were any developments. Perhaps predators had picked up the scent, as the wind was blowing away from us and into the surrounding bush. We were fully expecting to see predators or at least vultures on the carcass in the afternoon. Instead, the calf’s body was untouched and the bull and female had moved away. Some minutes later, we noticed the female coming into the water from the opposite side of the inlet with two Cattle Egrets on her back. It was clear she had abandoned her calf’s body by this time. 

Hippos are a very social species, living in pods of anything between 20 to 100 individuals. They lead very sedentary lives, resting most of the day and leaving their resting pools at dusk to feed. Most of their activity is nocturnal. Females are the leaders of the herd, controlling the centers of the resting pools. Males rest along the outer banks of the pools, protecting the females and calves.

Chobe river wildlife photography

Nature …. She pardons no mistakes. Her yea is yea and her nay, nay.

 – Ralph Waldo Emerson

If you look closely you will see the left side flank of this female hippo is badly lacerated. Compare this image with the one of the female standing over her calf. She must have been in some savage tangles in the intervening few hours – and her persecution was not over!!

Chobe river wildlife photography

In the previous image, there were two hippos all but submerged in the water as she entered. Immediately the aggression started. The first move was to go forward to meet each other and thrash their heads left and right as a warning. They bellowed loudly and swinging their head from left to right like giant sledgehammers, with wide open mouths and those razor-sharp teeth capable of deep cuts and punctures.

Chobe river wildlife photography

The tangle started with a bit of ‘argy-bargy’ but soon developed into something altogether more serious. They backed away momentarily and then charged each other again. The expression on the left hand hippo’s face showed this was for real.

Chobe river wildlife photographyChobe river wildlife photographyChobe river wildlife photography

The female who had just lost her calf was the one being attacked.

Chobe river wildlife photography

Chobe river wildlife photography

It is only when the fight gets serious do you get to see the impact of those tusk-like teeth digging deeply into each others’ open mouths. The hippos rammed into each other, slashing their heads from side to side. The thrusts were backed by two tonnes of body weight.

Chobe river wildlife photography

The strength of these hippos was evident, lifting their nearly two tonne bodies well out of the water. The fight went on for about five minutes and it was furious. A third hippo joined in the fray with two attacking the one female – the one who had lost her calf the day before.

Without context the whole process looked to be very unfair, but of course we did not understand what this altercation was all about.

Chobe river wildlife photography

Once outnumbered the beleaguered female tried to make a run for it.

Chobe river wildlife photography

As she tried to run away the other two females were trying to bite her side and backside.

Chobe river wildlife photography

Our guide said that if she stuck around there was a possibility the others would kill her.

In nature there are neither rewards or punishments – there are consequences.

 – Robert Green Ingersoll

The one thing you do not want to do in this situation is to get too close. All you need is to have three very angry female hippos come crashing into the boat. The 600mm lenses and able knowledgeable guides are critical in these situations.

Taking away human judgement on the situation, it was a good example of the different and sometimes awe-inspiring magnitude of nature that you are privy to when you are on the boat.

From a photographers point of view, capturing images of animals and birds and even landscapes from the water side allows you to get closer, gives a better perspective and allows you into scenes which you would not be able to see from a vehicle on the land side.

Nature uses only the longest threads to weave her patterns, so each small piece of her fabric reveals the organisation of the entire tapestry.

 – Richard Feynman

Seek to understand nature, marvel at its interconnectedness and then let it be

Have fun

Mike

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