Hippos

Hippo drama

The drought that Southern Africa is experiencing this year was evident already during our visit to Mana Pools in September. Despite the Zambezi River providing sufficient water, grazing was the main issue as the riverine pastures were very low and the patches of green left were those that are inedible.

Browsers and grazer/browsers were still in good shape but large grazers such as hippos and buffalos were already walking longer distances to get to areas that still had grass cover and these were dwindling fast. The hippos’ normal timetable was visibly altered as we “bumped” on several walking far from the water during the mornings and afternoons when, during normal years, they are in the water or sunning themselves by it.

Despite the Mana Pools “warning” the situation we found in the Kruger National Park (KNP) -Lower Sabie and Satara areas- was worse than expected. According to Swemmer (2016)[1] rainfall at Phalaborwa, one of the KNP’s camps, during 2014-15 was 255mm (the long-term average being 533mm) and the 2015-16 figures are extremely low. Two consecutive years of very low rain, combined with very high temperatures is regarded as rare and extreme. It is even likely that this drought will be the most severe since records started to be collected in 1954!

Different views of a very dry KNP (pictures by Mabel de Castro).

The consequences are there for all to see!

In the dry season the park usually has reasonable grass cover. This year there was almost no grass to be seen! The consequences of this could be immediately seen as few live hippos remained in the Lower Sabie River and the nearby Sunset dam. The ones we found looked rather strange and rather long-legged as their normally bulging bellies had shrunk enhancing their legs’ length! In addition, their skin hanged in folds, a consequence of their loss in body condition.

I regret that some of the pictures are disturbing but I need to show what was taking place.

We also noticed that the hippos did not move much and grazed on whatever they would find near the water bodies. As grass was scanty, they would just gradually weaken and die. Buffalo were also having a rough time and we only saw small groups looking thin. Interestingly, in some areas, both hippos and buffalo were doing better.

It is clear that the drought will have a severe impact on the animal population of the park but also on the vegetation cover as we also saw dry or drying trees that were also damaged by elephants searching for their own food. The re-establishment of grass, shrubs and trees will probably take years. The same applies to the animal populations that may not reach previous levels if the observed drier conditions become the norm in the future. In addition the drought will also accelerate soil erosion and modify the watercourses and other water bodies. Interestingly and somehow alarmingly, this is the first time that no Mopane worms have been recorded since surveys began in 2009 (Swemmer, 2016).

Trying to be optimistic about the future, it is possible that the current dry spell will have some beneficial impact by fine-tunning the situation to a future drier climate by reducing the herbivore populations while allowing vegetation to recover and, in a longer term, prevent overgrazing and environmental degradation.

Independently of the various possible interpretations of the impact of the drought on the environment, it is clear that even if the rains would come now, more animals will surely die before food becomes available. These are the ways of Nature, again.

 

[1] Swemmer, T. (2016). The Lowveld’s worst drought in 33 years? Understanding the long-term impacts. Consulted on 2/10/16. http://www.saeon.ac.za/enewsletter/archives/2016/february2016/doc02

 

Naughty hippo, again…

On our final day, after watching lions and birds, we planned a “sundowner” drink at Nyamandlovu pan to end our safari in style. Before it was time for drinks, we got busy watching the many migratory birds present at the pan. These were a large flock of Abdim Storks and Amur falcons that provided us with much entertainment while they fed on beetles and other insects found in the grass.

A family of five jackals, probably residents of the pan, were also around. While four of them were gnawing at an old elephant carcass, a fifth came close to the viewing platform for a look. As I was on the ground at the time I saw it coming and prepared for pictures. Despite the warnings shouted from above by fellow game watchers for me to be careful, I remained motionless and was rewarded with the closest encounter I have had with a black-backed jackal!

While watching the jackal I heard loud splashing noises coming from the pan and I saw a large crocodile (one of the three present) coming out of the water holding a very large chunk of carcass. I left the jackal to its business and rushed up the platform for a better look. The beast, at the left end of the pan, was violently shaking the carcass and scattering pieces in the water while it swam off with the remains to the opposite end.

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The crocodile feeding on the submerged carcass.

The slow approach of a hippo to the area where the carcass had been shaken apart came as no surprise to my family and I, all well aware by now of our earlier observations on meat-eating hippos at Masuma dam![1] We watched while the hippo approached and searched the area with its head submerged. Suddenly it lifted its head and chewed on what appeared to be a piece of the carcass that it had found! This was a very interesting observation, as we had not seen any of the three resident hippos engage in this activity before, despite having spent many hours there!

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The hippo starts approaching…

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Eating a chunk of the carcass that the crocodile left.

After munching on its find, the hippo left the area jumping in the water in a rather funny display that probably expressed approval at what it had just eaten! Fortunately I managed to take a picture of the crocodile (regrettably only after the carcass shaking took place…) and of the hippo finishing its snack and merrily moving off!

 

 

[1] See https://bushsnobinafrica.wordpress.com/2015/02/22/hippos-from-hell/ and https://bushsnobinafrica.wordpress.com/2015/03/23/hippos-from-hell-the-videos/ Muy Interesante also covered this issue: http://www.muyinteresante.es/naturaleza/articulo/los-hipopotamos-pueden-comer-carne-921450193942

Hippo disclosure

While searching for suitable pictures to post in Instagram (#bushsnob, just in case you are curious…) I found a picture of communal defecation by hippos at Masuma dam. As I have recently -and entirely by virtue of being observant- become involved with facts about hippos that will probably change the way we look at them, I thought this short post was justified.

5 - Hippo rescue attempt at 2 second view

Hippos chasing crocs to get at the impala carcass!

There are many great stories about animals in Africa and, although I learnt this one some time ago, it had been stored in a part of my brain that I no longer have access to, because of all the new activities I am involved in (the real reason will not be disclosed!).

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A hippo “tusker”. Note the left tusker also protruding in the upper lip.

Anyhow, apparently when the world was created, God, as you can easily imagine, encountered many problems. A lot of them God solved immediately but several remained, perhaps because God was busy solving the important ones. Among these was the “Hippo problem”. The latter found itself in a dilemma about its lifestyle that required a consultation with God.

“God” hippo said, “I know you have created me, but what do I do now? What do I eat? Where do I live?” A busy God did not have time for individual animal bellyaching so, from the top of his head said: “Well, you will live in the water but you will eat grass”. Surprised Hippo repeated “I will live in the water but I will eat grass?” This did not make too much sense to it as it had seen his reflection in the water: big mouth and big teeth! “How am I going to convince fish that I will not eat them? They will not let me enter the water!” he commented. Still busy, God told Hippo to make a plan!

Hippo left God’s office deep in thought and organized a meeting with the fish to convince them of his life plan. “I must prove to the fish that I have not eaten them!’ thought Hippo, and he met with the fish and eventually they came up with a pact: Hippo could spend the days with them in the water if he could prove he was not eating them. Hippo would prove this by spreading its dung each time, to prove to the fish that he was a trustworthy neighbour! Hippos still do to this very day.

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Hippos defecating together in the water.

As you know, hippos spin their tails while defecating to distribute their excrement over the greatest possible area and, contrary to what I thought, hippo defecation occurs in the water and it is not rare to see fish following them. Male hippos in particular are very precise in the spreading of their excrement!

Funnily enough, I do not remember having witnessed a hippo peeing! Apparently they pee backwards and are known as are retromingent animals.

Enough of hippo’s bodily functions!

A “new” hippo

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Those of you who have read this blog on 22 February 2015 (https://bushsnobinafrica.wordpress.com/2015/02/22/hippos-from-hell/) and watched the videos I posted later (https://bushsnobinafrica.wordpress.com/2015/03/23/hippos-from-hell-the-videos/) would remember the extraordinary observations that the hippos present at Masuma dam at Hwange National Park were actually eating Impala meat. A reminder below:

This observation was so incredible to us –seeing it happening in front of our eyes without previous knowledge- that it was almost the sole topic of conversation for the rest of the trip! It was only after we returned and I found an earlier record of a similar event also observed at Masuma almost 20 years earlier[1] that my mind relaxed, but only for a short while. What we thought that happened it was what actually took place! I believed that the observations were of great importance and that they merited further follow up!

Luckily, establishing contact with Joseph Dudley (Joe), the responsible of the observations and publication, was straight forward and he replied to my message telling him of our experience within 24 hours! The possibility of some collaboration to write our observations was considered from the start. Later on Joe realized that there were a few reports and that it was worthwhile attempting a joint paper. On 20 October 2014 he wrote: ” I think that it would be good to connect the dots between these three recent observations ………..”[2] This was the start of Joe’s efforts to put together the people that have had experience on hippo carnivory and although he asserted to me recently (2 December 2015) that ” It was your contacting me after your experience in Hwange that pushed me to made this paper happen…” the idea of the joint paper and the effort of writing and coordinating it was his! My contribution to the exercise was minimal and I could safely say that I was only the straw that broke the camel’s back!

Civilities aside, Joe managed to put together a group of people with complementary expertise and steered it to the publication of a paper that I believe will change the way we look at hippos in the future[3].

In brief the paper postulates that hippos, an essential species within their ecosystem, should be considered not as obligate herbivores as at present but rather as facultative carnivores able to consume carcasses from other animals. Carnivory is not an aberrant behaviour confined to certain instances but a behavioral trait that takes place throughout the hippo’s distribution.

The accelerated rate of transmission of the deadly zoonotic disease anthrax recorded among hippos as compared with other animals is attributed to their habit of consuming meat from various animals, including the hippos themselves. This fact can have important implications for a better understanding and better management of future anthrax outbreaks not just in wildlife populations but, much more critically, in humans. The publication is receiving a rather wide coverage by the world press that I include on a separate page for reference. See: Hippo carnivory press coverage.

Just today (10 December 2015) Joe sent me a video from YouTube that I think is very timely as it rather eloquently shows hippos consuming a zebra and fending off crocodiles while doing so. You can watch the video below although it may be a bit too strong for some. Please accept my apologies but I think it is within the very interesting subject of this post.

I end this post with a picture of a hippo taken on the Kavango river during our recent trip to Namibia that I will cover soon. Does it not look too fierce to be a herbivore?

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[1] Dudley, J.P. (1998). Report of carnivory in the common hippo Hippopotamus amphibious. South African Journal of Wildlife Research 28, 58-59.

[2] At the time he had additional information on the subject from other colleagues.

[3] Dudley, J. P., Hang’Ombe, B. M., Leendertz, F. H., Dorward, L. J., de Castro, J., Subalusky, A. L. and Clauss, M. (2015), Carnivory in the common hippopotamus Hippopotamus amphibius: implications for the ecology and epidemiology of anthrax in African landscapes. Mammal Review. doi: 10.1111/mam.12056. The paper can be downloaded free from the following link for the next couple of weeks: http://wileyonlinelibrary.com/journal/mam ffollhttp://onlinelibrary.wiley.com/doi/10.1111/mam.12056/abstract for the next two weeks and then the Abstract will remain there.

 

Mana[1] Pools safari

Mana Pools National Park is found in the middle Zambezi valley. It extends from the Zambezi river in the North (Zimbabwe-Zambia border) to the summit of the Zambezi escarpment 50 km to the South. The park includes the river itself, a broad area of acacia and mahogany woodland on a belt of alluvial terraces. Although this is the area where most of the animals congregate during the dry season and therefore the most visited, the Park also includes large areas of mopane and jesse-bush (Combretum celastroides) and the rocky hills that flank the Zambezi valley. The Park and adjacent areas are regarded by many as the finest wilderness area in Zimbabwe.

Sunset at Mana Pools.

Sunset at Mana Pools.

This was our second visit this year as we had been in Mana. At that time it was cold and the animals, particularly the elephants, were still spread around in the park and therefore less abundant by the river. The absence of elephants then was largely compensated by sightings of wild dogs, lions and a leopard near our camp site.

This visit was different. It was much warmer and, as the dry season had advanced, the animals were indeed massing in the northern part of the park where water and grazing are still available. We stayed at Chitake One and at Gwaya private camp sites so we enjoyed a true wilderness feeling by being alone. Without doubt the elephants were the main actors during our visit and I hope to be able to describe the various events in an amenable way for you to enjoy.

[1] “Mana” in Shona means Four, describing the four pools that the Zambezi river left behind in its meandering.

Hwange National Park

Last year I reported on our stay at Shumba Picnic site in Hwange National Park in Zimbabwe (see: https://bushsnobinafrica.wordpress.com/2014/10/31/watched-at-shumba/) as well as the observations we made on the struggle we witnessed between crocodiles and hippos for the impala carcasses at Masuma dam (see: https://bushsnobinafrica.wordpress.com/2015/02/22/hippos-from-hell/ and https://bushsnobinafrica.wordpress.com/2015/03/23/hippos-from-hell-the-videos/).

Hippos were not interested in Impala meat this time!

Hippos were not interested in Impala meat this time! (Photo by Julio A. de Castro & Mariana Terra)

(Photo by Julio A. de Castro & Mariana Terra)

(Photo by Julio A. de Castro & Mariana Terra)

After our return from that safari we immediately booked the Masuma dam campsite so that we could stay closer to the action and see if we could observe something additional in the crocodile-hippo saga that caught our interest earlier. We also booked a place in Main Camp as we were sure we would have fun with elephants at Nyamandlovu pan. We knew that the elephants were plentiful there and we could watch them and enjoy their antics!

THis time there were lots of elephants at Masuma dam. (Photo by Julio A. de Castro & Mariana Terra)

This time there were lots of elephants at Masuma dam. (Photo by Julio A. de Castro & Mariana Terra)

We even saw pink elephants... (Photo by Julio A. de Castro & Mariana Terra)

We even saw pink elephants… (Photo by Julio A. de Castro & Mariana Terra)

As part of our “discovery drive” we also camped in the Ngweshla pan campsite as it has a reputation as the best place to camp in Hwange and is a place where predators are often seen because the area surrounding the various pans and water holes found there is quite open, a change from the thick bush of other areas in the park.

The safari took place between 22 and 29 July 2015 and I describe its highlights in four posts:

Fearless bee-eater

Moonlit elephants

Encounter with lions, and

Ngweshla cold.

 

I hope you will enjoy them.

Hippos from Hell

In an earlier post I described how Crocodiles[1] were stalking and catching Impala at Masuma dam[2]. What I did not mention yet was what happened next. You will not regret reading on!

Masuma Dam is located in the Hwange National Park (18°43’52.20″S 26°16’47.82″E). The observations described here took place on 13/10/14 from 10.00 to 12.00 hours and on the 15/10/14 from 09.00 to 12.00 hours. The dam is about 120 by 100 metres and it has a roughly oval shape with the viewing platform located on one of the longer parts of the oval.

A "panorama" view of Masuma Dam.

A “panorama” view of Masuma Dam.

The time of the observations correspond to the end of the dry season. At this time of year many animals come regularly to drink at the dam. Apart from elephants, Greater Kudu, Waterbuck, Impala, Zebra and Warthogs were seen everyday. We also saw large flocks of guinea fowl, various doves, vultures, kites, buntings, starlings, among others. At the time there were sixteen resident Hippos, both adults and young animals as well as at least six mature Crocodiles.

Map of Masuma Dam showing the various places mentioned in the text.

Map of Masuma Dam showing the various places mentioned in the text.

Impala herds drank mainly in the morning, mostly at Point 1 in the drawing. Aware of this daily event, Crocodiles were observed to ambush the Impala by positioning themselves across the small bay where the antelopes drank. Usually one of the Crocodiles would approach the Impalas in full view up to 1 to 1.5 metres from them. This created noticeable nervousness on the part of the Impala but they would gradually calm down and drink. The Crocodiles would remain immobile for a few minutes and then slowly sink and completely disappear. Most of the time, the Impala continued to drink and moved off and the reptiles remained quietly submerged.

A Crocodile attack at the Impala drinking area.

A Crocodile attack at the Impala drinking area.

About two or three times in a morning, the hidden Crocodiles lunged towards the Impala. As soon as the swirl that precedes the attack was noted, the Impala scattered in all directions (including into the water!). The most common outcome was that the Crocodiles failed and went back to the water empty-jawed. On one occasion a young animal was caught from its leg and, after a short struggle, it was drowned. This happened only once out of 8-9 attacks we witnessed.

The Crocodile swims away with the freshly caught Impala just before it was chased by the Hippos for the first time.

The Crocodile swims away with the freshly caught Impala just before it was chased by the Hippos for the first time.

While the struggle between the Crocodile and the Impala was taking place, two Hippos approached the area and were seen chasing the Crocodile. The latter submerged and took off while the Hippos lost interest and we speculated on their noble “rescue” attempt.

The Crocodile with the Impala at Point 2.

The Crocodile with the Impala at Point 2.

Ten minutes later the white belly and legs of the Impala came to the surface at Point 2 and caught our attention. A Crocodile held the dead antelope and others came to feed on it. This, again, prompted a swift response from the Hippos, who came back and confronted them quite aggressively.

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The Hippos "rescue" attempt at Point 2.

The Hippos “rescue” attempt at Point 2.

Another view of the Hippos' "rescue" attempt at Point 2.

Another view of the Hippos’ “rescue” attempt at Point 2.

The subsequent struggle involved a Hippo pulling from a leg while the Crocodile pulled from another part of the animal. As the Hippo did not have a good grip on the leg (its teeth and mouth do not facilitate tug of wars), the Crocodile retained the Impala and, again, swam off with the carcass (or part of it as we could not see if it was split or broken up) towards Point 3 in the drawing.

The Crocodile avoided the Hippos at Point 2 and moves to Point 3.

The Crocodile avoided the Hippos at Point 2 and moves to Point 3.

The crocodile stayed at Point 3 for about 30 minutes with the Impala (or a large part of it) in its mouth until another Crocodile came and started to pull and tear at the carcass. In about a minute, a hitherto unseen/submerged Hippo[3] burst into the middle of the tug forcing the Crocodiles to scamper again.

A Hippo moves towards the Crocodile at Point 3.

A Hippo moves towards the Crocodile at Point 3.

The Hippo tug of war with the Crocodile!

The Hippo tug of war with the Crocodile!

The Hippo tries to bite the Crocodile.

The Hippo tries to bite the Crocodile.

The Hippo chases a Crocodile while the other one escapes with the Impala towards Point 2.

The Hippo chases a Crocodile while the other one escapes with the Impala towards Point 2.

The Hippo keeps chasing the Crocodile while the other one swims away.

The Hippo keeps chasing the Crocodile while the other one swims away.

While the Hippo chased one Crocodile the other one, still holding the carcass, swam back to Point 2 where it remained for another 10-15 minutes when, once more, its companions arrived and started to tear at the carcass.

The Crocodile are attacked again after arriving at Point 2.

The Crocodile are attacked again after arriving at Point 2.

Another view of the struggle for the Impala at Point 2.

Another view of the struggle for the Impala at Point 2.

Another view of the Hippo vs. Crocodile struggle for the Impala at Point 2.

Another view of the Hippo vs. Crocodile struggle for the Impala at Point 2.

The Hippos came again and were seen clearly attacking the Crocodiles and even biting them.

One large Hippo bit the head of a Crocodile, who swiftly moved away to avoid severe consequences while other Hippos were also seen biting crocodiles on different parts of their bodies. In the commotion we lost sight of the

Calm was reinstated at the dam for about 20 minutes. The next thing we noticed was a great commotion at Point 4 where the Hippos began to congregate. They were clearly competing for something and eventually several were seen apparently “mouthing” the Impala. On closer observation they were actually chewing and apparently swallowing while bone-cracking noises were heard.

After snatching the Impala from the Crocodiles at Point 2, they congregate to feed on the Impala carcass.

After snatching the Impala from the Crocodiles at Point 2, they congregate to feed on the Impala carcass.

Another view of the final stages of the Hippo feeding frenzy.

Another view of the final stages of the Hippo feeding frenzy.

Unbelievably to us, at the time of these observations, the Hippos were eating the Impala! After it was consumed the Hippos went back to their normal place and peace returned. The moment they lost the carcass, the Crocodiles did not try to recover it.

Confinement in the dam was the best possible explanation I could think at the time for such aberrant behaviour. The event appeared so unusual that, on arrival in Harare, I went straight to the computer to check the Internet. Not surprisingly, I found earlier references of similar incidents and the first report of carnivore behaviour in Hippos came from Masuma Dam![1]

As, very recently the BBC and National Geographic have both published articles on hippo cannibalism[2] I put together these observations to contribute to our general knowledge. I have also contacted Mr. Dudley and we are collaborating on the subject that may result in further work being published in the scientific literature.

[1] It was not easy to see the number of Crocodiles or Hippos involved in the various incidents described.

[2] https://bushsnobinafrica.wordpress.com/2014/10/27/crocodiles-and-impalas/

[3] I was excitedly filming the scene!

[4] Dudley, J.P. 1996. Record of carnivory, scavenging and predation for Hippopotamus amphibius in Hwange National Park, Zimbabwe. Mammalia 60 (3): 486-490.

[5] http://news.nationalgeographic.com/news/2015/01/150123-hippos-cannibalism-animals-food-science/?utm_source=Facebook&utm_medium=Social&utm_content=link_fb20150125news-hippos&utm_campaign=Content&sf7093531=1

and

http://www.bbc.com/earth/story/20150116-the-diet-secrets-of-hippos-herbivore-or-cannibal