It’s hard for a shepherd when a bear pays a call. It isn’t a good time for me to visit, but when I set out, I know nothing of all this.

Mustaphá has invited me to the Mont Roig estive (summer pasture). I want to arrive before he and his assistant Josep take their flock for its daily stroll. As a result, I find myself climbing through the fir trees by the light of my headtorch. After an hour and a half, the forest starts to thin out and dawn begins to trickle over the ridge, but it takes me the same time again, still climbing, to reach the estive. Last night’s thunderstorms have left the grass wet, but the sun is now flooding the skies.

Patous (livestock guardian dogs) at work.

The edge of the estive is marked by a triangular sign warning that patous are at work. Beyond it, the grey wall of the glacial cirque rises vertically out of the grass and rocks. In the hollow enclosed by the cirque, I can see the sheep, lightly constrained by electric netting, a more sophisticated version of the traditional electric wire fence. It looks like the kind of netting used by fishermen. Not only is it strong, but also every strand has a wire running along it, powered by a solar panel.

There must be roughly a thousand animals in this temporary sheepfold. Some are marked T, others F. After last night’s rain, the ground is muddy: the netting will need to be moved soon. Next to it is a tatty off-white portacabin that must be on holiday from a building site. We are 2200m above sea level.

I spot Mustaphá further up the cirque, just below the cliffs, clearly identifiable by his curly black hair. The man who has just joined him must be Josep. They are both bending down.

I circumnavigate the sheep’s enclosure. There is one ewe outside, apparently trying to get in. Josep stands up as I approach and walks towards me, opening his hand to show me a hair. Of a bear. I just have the time to take a photo before the wind blows it away. We all get down on our hands and knees.

"Never mind, there's another on the rock."

— Mustaphà

“Never mind, there’s another on the rock,” says Mustaphá leading me to a blood-splashed stone and pointing out the evidence being left in situ for the experts. Some of the red patches are still damp.

The sheep itself is a few metres away, lying on its back in a gully. Its eyes are half-open, but its neck is a crimson mess of tendons. Something greyish, which might be its heart, is visible through the rent in its chest. Its abdomen has also been opened up to reveal more sinews and a greenish bulge. The rest of the body is intact.

It looks like a classic case. The bear must have clawed the sheep’s neck, and then started eating the most accessible innards. I’m surprised at my own reaction or – rather – lack of it: I’ve seen too many pictures on the Internet to be shocked. But I hadn’t anticipated the smell: sweet and sickly, acrid and something… disgusting, but what is it?

All three of us look at the corpse from a distance, not saying anything.

What is there to say? By the time I have taken a few more photos, the others are heading back down to the hut, still silent. They want to let the sheep out of the fold and take them for their daily ramble. Josep needs to find something to cover the corpse.

Mustaphá waits for me half-way back to the hut and tells me what happened. Yesterday evening it began to rain. The shepherds feared that the clouds would descend, so they started herding the flock back into its electrified nest. The border collies did their best, but three sheep preferred freedom. In the middle of the night, the patous (livestock guardian dogs) started barking. Mustaphá has no idea exactly when; a child of the mountains, he measures time by sunset and sunrise.

The shepherds got up and went outside. The three patous were chasing something away down the valley. Mustaphá points to the hillside immediately above the path I have just used. The shepherds could not see what it was but there are no stray dogs in this remote location. No wolves. It must have been a bear. Despite their powerful torches, they could not see the three sheep either. When things had calmed down, they went back to bed and slept in longer than usual. But when the border collies came in with blood on their noses Mustaphá knew that there was a problem, so they got dressed quickly. It was the vultures pecking at the carcass left by the bear that led them to the site.

The vulture flies so near my head that I can feel the downdraft

When we arrive at the hut, I look back in the direction of the dead sheep. The vultures are closing in again.

“I’ll get some sacking,” Josep tells me.

Nature will have to wait to do its job. The sacking will keep the vultures off until an autopsy has been performed and the official compensation claims completed.

I offer to chase the vultures away and climb back towards the corpse, leaving Josep to rummage in the hut. I am a little anxious because there are a dozen birds now. I am a few paces away from them when those on the ground take to the air, flying so near my head that I can feel the downdraft. I look up, tottering. Stretching out my arms, trying to keep my balance, I realise that the birds’ wingspan is bigger than my arm span. If one of the birds seriously wanted to, it could easily knock me over. Having gained height, the vultures circle above me, biding their time.

Although it has only taken me ten minutes to get here, the corpse has been transformed. The rib cage is now completely empty and the flesh on the hind legs has also been eaten. There is a green mess where the lower abdomen used to be. The sheep’s last supper is slopping out of its punctured rumen. The smell has become a stench, and now I can identify it: a combination of digestive juices – the smell of sick – and rotting grass. I move upwind.

Josep arrives soon after with the sacking, which we weigh down with stones. The other sheep have now been let out of the enclosure for the day. Josep and Mustaphá will join them shortly.