But nothing goes to waste.
The death of a hippo provides a meal
for the river's most fearsome and efficient predators:
the Nile crocodile.
Growing up to five metres in length, these crocodiles hunt and scavenge.
That's a load of crocs.
A hippo carcass just down the river from the studio
is instantly set upon by these voracious reptiles.
This is about a hundred metres in front of us
a classic Luangwa eat
embedded in the water and about 30 crocodiles.
What's amazing is that there are three hippos that are coming in,
actually trying to force the crocodiles off the carcass.
Obviously, mum would be one of them.
There seems to be a whole gang trying to force the crocs off
while they tear this thing to pieces.
It's pretty primeval.
Hippos and crocodiles normally coexist peacefully,
but crocs will take every opportunity to prey on a weak animal
or scavenge a dead one.
We've seen one or two of these hippos doing these big yawning displays,
which is a threat to the crocodiles.
They're trying to drive the crocodiles off with this big yawn and sharp teeth.
The crocs obviously are not intimidated by that at all.
The crocs are here in numbers,
so the hippos have got no chance really of driving them off.
Alison Leslie is one of the foremost authorities
on Nile crocodiles.
She explains to one of the film crew
the unique manner in which the crocs feed.
If it's a bony chunk they will literally just crush 2,000 pounds per square inch.
They'll crush it until it's soft enough that they can just swallow.
If it's a chunk of, say for example, skin or innards, they just pull him out.
He's shaking, shaking, shaking
until his food literally slides down their throat.
There's some sort of hierarchy there.
They rely on each other to actually grab onto either end of a piece of prey
and then they rotate in opposite directions,
so although to us it looks like this mad frenzy and splashing,
there's actually a really controlled system in place.
Amazingly so.
Everybody's concentrated in areas, the hippos are dying off, you know,
slowly but surely,
and these cleaning machines have come in just to keep the system freshened up.
Crocodiles are opportunists.
They feed on fish in the river,
and at this time of year,
will make the most of any dying or dead hippos,
but they will also take advantage of any animal coming to the river to drink.
With that sort of number of crocs in an area,
obviously, if there's an impala on the bank,
there's gonna be a number of crocs.
If we don't get rain, there's going to be a bit of an uproar in some of these areas.
So for the thirsty animals,
this croc-infested river is as dangerous as it is necessary.