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Altered Behaviour in Animals - Drought-related?

I hope you may find the following thread of pictures interesting, these are personal observations of processes I have not yet observed in the field before.

These are by no means scientific opinions in any way, just interesting observations of what I believe is drought related – a knock on affect if you like, that alters routine behaviour in animals.

What I have noticed is that elephants (Loxodonta Africana) are particularly targeting the larger marula trees (Sclerocarya birrea), and appear to be utilising the trees in an unusual way. Massive branches from the main trunk are being snapped off, in some cases the entire tree being destroyed. You can tell when an elephant spends time in one place or is simply passing through.

What is evident now is the time the elephants are spending stripping off all the bark off the smaller ancillary branches. This must take an elephant ages, and what is left behind is this mattress of shredded bark. The dung content does not suggest the elephant is ingesting much of the bark. So why would it spend all this time stripping the bark but not eating copious volumes of it? Is there a particular nutrient stored somewhere in the branch that elephants instinctively know where to find, and is triggered by stressful conditions such as drought?

Another observation is an increase of elephants feeding on tree roots. Yes, we know at this time of the year elephants target Grewia spp, kicking the soil and uprooting the Grewia to feed on their roots. I see Apple-leaf (Philenoptera violacea) roots being targeted, careful selection. Apple-leafs tend to occur in communities, again the elephants spending time digging up these roots to feed on them, and this I have not noticed during times of plenty.

Elephants are also targeting red bushwillows (Combretum apiculatum), especially the medium to large specimens which usually play second fiddle to the newer recruits.

1606 behaviour 07Out and about buffalo (Syncerus caffer) are targeting African wattles (Peltophorum africanum), using their horns to rub off the bark, also difficult to establish levels of ingestion, but why the wattles specifically? I can only suggest another nutrient needed for survival during these challenging times.

Along the tar road I watched buffalo grazing the grass species Bothriochloa, currently dry and moribund in form, and this grass is usually never utilised in its mature stage. It just goes to show how desperate the grazers are for food.

The Bothriochloa observation can be explored and debated in depth because when you look at the model of “Holistic Management” (Google this term if you are interested in ecology) which supports and encourages non selective grazing. The consumption of Bothriochloa then demonstrates that the drought can have positive effects on ecological processes. Non selective grazing results in utilisation of all the grasses, so the moribund layer disappears and bodes well for new growth vigour when the rains finally come. This is optimum nutrient cycling.


 

by John Llewellyn