Darren Matthews is right to characterise the Colwick Park ruddy duck cull as 'scientifically flawed' and expensive (Anger over Colwick Park duck cull, November 27). It is also extremely cruel. 'Trial culls' of ruddys in other parts of Britain resulted in birds being shot a dozen times and lingering for more than 90 minutes before finally expiring.

The ruddy was brought to this country from North America in the 1940s by the Wildfowl and Wetlands Trust, as an 'ornamental' species. A few escaped and bred in the wild. Their numbers increased to several thousand and some of these were said to have reached Spain and mated with a rare duck called the white headed – rare because it had been hunted and its wetlands habitat destroyed by people.

'Conservation' zealots at RSPB headquarters decided the 'impure' product of this union had to be hunted and destroyed. But nature is not pure, or fixed. The mating of close genetic kin is a fact of bird life,

The Spanish have now taken action to preserve the main breeding grounds and their white headed population has since grown from just 20 or 30 birds to between 3,000 and 5,000. Meanwhile, as a result of warmer British winters, ruddy duck migration to Spain has virtually stopped. Just four were spotted (and killed) in 2006. As a consequence, hybridisation – which should never have been seen as a problem – is probably no longer taking place. Given that arguments for the cull were founded on putting a stop to hybridisation, the pro-cull argument is dead in the water.

ANDREW TYLER Director, Animal Aid Bradford Street, Tonbridge, Kent