Or éco-pâturage à Paris, in the more elegant French description.
As the sign shown here explains, they are to provide a more ecological way of maintaining the lawns, munching though the grass, and thus ending the need for fossil-fuel-driven mowers and chemical weedkillers. The result should be an environment richer in flora and fauna, all naturally fertilised, providing a reminder of nature and a wildlife corridor in the middle of the city.
Provided with water, shelter and an unobtrusive electric fence (solar-powered of course) to keep them safe, the tough little sheep have been chosen because the breed offers no value to the meat or dairy farmer, and was otherwise at risk of dying out.
It is a scheme that has received a good deal of positive media coverage. As our American friends might say, what’s not to like?
Except, sadly, on my visit to the archives last month, it looked as if the experiment was not working. Although they appeared to be munching as required, the sheep were almost hidden by grass that must have been a metre high. They were rather disconsolately gathered in one corner near the building, and gave me the impression that it was just all too much for them. The only short grass was a small strip on the public side of the electric fence, which was presumably being mown in a less environmentally-friendly way.
No doubt the city took advice on how many sheep would be needed for an area this size. And maybe there is a required pattern of feast and famine, and I witnessed the very start of a period of feasting. So I am still hoping we may yet see more tough little brown sheep nibbling their way across the green spaces of Paris. It just seems not to be as straightforward as you might hope.