There is one key creature at the heart of the park that managed to escape the horrors of the civil war, and is actually doing its part to keep the ecosystem from collapsing.

Nile crocodiles by the hundreds plunge into the safe haven of Lake Urema at the first sight of humans.

There, they can stay underwater for hours, a talent that no doubt helped them evade the guns of hungry soldiers.

And here, they can satiate their hunger by hunting their main prey — catfish.

The crocs by eating the voracious catfish are actually a blessing for the park.

In other places where the crocodiles have been killed off, catfish have multiplied out of control and destroyed entire ecosystems.

Other fish populations crash, the birds that feed on them follow.

The birds' droppings that fertilise the water disappear.

Gorongosa's crocodiles keep this environmental death spiral from occurring.

The other great keepers of the lake, hippos, are still too few to help restore the park to its former greatness.