Cruelty of zoos

cables and failed kites. Windshear – abrupt changes in wind speed and/or direction – is no doubt the biggest problem here. Places to avoid would include mountains and areas with frequent turbulent weather, which could preclude northern Europe.

Huge areas without humans would be needed for deploying enough kites. Perhaps they would need to be at sea, which would increase costs.

A workable energy system needs to give us significantly more energy back than the energy used to manufacture, deploy and maintain it. The claimed payback for onshore wind, for example, is 18 to one or thereabouts. The developers of Mr Cross’s kite generators are claiming a monumental return of higher than 300 to one! If this is true then I’m surprised that they are saying that their devices are not profitable, even if they are not currently eligible for subsides. It is also surprising that the proponents are claiming that kite generators are the world’s cheapest energy system.

GEOFF MOORE Braeface Park, Alness We feel awful for Kumbuka, the escaped gorilla, who – like any living being – longs to be free, but we’re grateful that unlike an American zoo which recently shot a gorilla dead, London Zoo acted in a humane manner.

The salvation of these endangered species lies in habitat conservation, not a life spent behind bars – because the truth is that hardly any captive-born gorillas are released to their natural jungle homes.

It’s time the public stopped paying to see miserable animals in captivity and instead worked on solutions to help them thrive in their natural environments.

JENNIFER WHITE All Saints Street, London