We were travelling along the unmade road to the cloud forest at Monteverde in Costa Rica, and stopped by several vehicles at the roadside. A sloth was visible high up in a tree, gawped at by those standing by the vehicles. There was also a troupe of howler monkeys, swinging rapidly from branch to branch, difficult to photograph.

When I examined the images of blurred swinging shapes back home, there was this one really good frame of a monkey looking down on the motley crew of tourists. Who was observing whom?

His look says to me, what are you doing in my world? Even the unmade road and the occasional roadside shack have invaded his wilderness, his world.

We were told that there is controversy in Monteverde over whether to tarmac the road to improve access for tourists. Sadly, the coming of the tarmac seems inevitable, of course followed by more dwellings, hotels and so on. Development seems to be a one-way street away from the wild, even in the name of the tourism that aims to protect it.

At least Costa Rica still has a relatively large amount of virgin, fertile and protected land, so nature has a better chance than in most countries.

The call of a howler monkey can reach 128Db and be heard over several miles
– one of the loudest animals on earth.