File photo: 'This meant the adult crows had fed their chicks 160 small tortoises as they raised them.'

Cape Town - How many juvenile tortoises can a crow chick eat? Quite a few, based on what a perceptive Ceres Karoo farmer discovered on his land recently.

Nollie Lambrechts, a veteran Ceres Karoo farmer, used to run sheep on his farm, Fonteinskop – about 10km from Karoopoort – until four years ago when he decided to change over to game farming.

Since then the farm has lain fallow.

“About eight months ago, a worker on the farm brought me some small tortoise shells and told me crows had eaten them. I did not take note at first, thinking it was probably only an occasional thing,” Lambrecht said at the weekend.

“But then, on September 18, I first noticed a crow’s nest at the top of a wind pump and, when I climbed up to take a closer look, I saw five eggs in it.

“On September 22, four chicks hatched and the fifth egg was bad.”

That was when a natural drama began unfolding before Lambrecht’s eyes.

“On September 30, we found four small tortoise shells on the ground beneath the wind pump and, when I climbed up again, the four little chicks were stretching their necks and holding their mouths wide open expectantly,” he said.

When Lambrechts returned to the site on October 13, he found 41 small tortoise shells on the ground. By October 21 the number of shells had increased to 100.

“I then only returned to the site again on November 5. The crows had left [the chicks had left the nest] and there were a further 60 small tortoise shells on the ground.

“This meant the adult crows had fed their chicks 160 small tortoises as they raised them.”

Lambrechts said he at first began hating crows because of the damage that this pair and their chicks did to another species: “I have noticed before that there weren’t so many tortoises on my farm anymore, but didn’t think too much of it. Now I have to ask myself what is the purpose of a tortoise? How many eggs does a tortoise lay? These crows could have hunted in a radius of about 10 to 12 kilometres, if not more – my farm is quite narrow and surrounded by game farms, so this means they must have found prey on the two neighbouring farms, too.

“What I’ve also noticed is there are fewer and fewer small game. I think the jackal had hunted the small game to low numbers. When we still had sheep on the land, there’d always be something dead for the crows to feed on, but since the sheep had gone, they might have run out of dietary options.”

Scientists who discussed the issue said they would have to do further research to find answers. - Cape Argus