On September 17th last year, the witty and intellectual Tom Imrie wrote a post on the current El Niño Southern Oscillation (ENSO) currently ensuing across the globe. This ENSO is one of the strongest on record and as many had predicted, has resulted in substantially lower than average rainfall across Southern Africa. In a prophetic way, Tom warned that times would be tough for animals at Londolozi should these predictions be accurate. At the time I decided to note any changes in animal behaviour over the next seven months and what I noticed truly enhanced my appreciation and understanding of how intricate the web of relationships between the animals of Londolozi can be.
To date this season, Londolozi, which usually receives an annual rainfall of approximately 600 mm, has only received 333 mm of rain. This is on top of a similar shortage of rain last summer. As a result of this, combined with the standard effects of lower winter temperatures, grass and tree cover have been sparse and several animals have needed to venture further to find food. Most affected by lower than average rainfall are the herbivores. A study during one of the worst droughts in the neighbouring Kruger National Park in 1992 showed that it was kudu, buffalo, waterbuck, buffalo and wildebeest that were most affected. Predators, on the other hand, thrived during this time.
Over the last few months the survival instincts of animals at Londolozi have been amazing to see. Hippos are a case in point. Hippos generally spend most of their day in water, venturing out at night-time in search of grass. During times of drought one would expect that hippos would be stressed because there is less water. Although this may indeed be the case, hippos at Londolozi are still managing to find suitable waterholes and deep pools in the rivers, but tensions in these pools are high. Finding food is their main agenda. Hippos typically eat between 30 kg and 50 kg of food an evening to sustain their large bodies. However, when food is limited they need to graze further away from water, and for longer. Elmon and I have been seeing hippos grazing in the midday sun far away from water, as well as hippos resting in mud wallows up to 10 km from the nearest permanent water sources. It could be that these hippos ventured so far from their usual water holes that they simply couldn’t make it back before the next morning. Nonetheless, they are doing what they need to.
Buffalo have also been showing some strange behavioral anomalies. Buffalo are regarded as bulk grazers, eating mostly grass. However, grass is limited at the moment and Elmon and I have noticed several herds of buffalo passing through areas devoid of grass and eating leaves from trees like the apple leaf and sickle bush. This is not something that is commonly seen as typically leaves make up less than 5% of a buffalo’s diet. They too, are doing what they need to.
Lions on the other hand are supreme opportunists and herbivores in distress often allow lions to thrive. During the 1992 drought discussed above, lion numbers increased from one lion every 30 km2 to one lion every 9 km2. Over the last week alone we have seen the Mhangeni breakaway pride catch and eat two buffalo and a zebra in the space of three days. The Matimba males robbed them of one of these buffalo and did not even finish the entire buffalo before abandoning it to masses of white-backed, hooded and lappet-faced vultures. The low rainfall could mean that other prides like the Mhangeni, Sparta and Tsalala prides could fare extremely well.
Tom’s statement holds true; we are in for very interesting times at Londolozi this year. The dry conditions have a very important role to play and the animals which can adapt to the tough conditions will prevail in the long run. Some may do better than others and I believe we are going to see some amazing things over the next few months as we watch the natural ebb and flow of this delicate ecosystem.