[Bramblecot]

That's what my fields look like after I've run a harrow over them. 
Surely they are just dragging up all the thatch and dead stuff?  I don't like the look of those chafer grubs though , must go and look them up .  We have leatherjackets on our heavy, wet clay - could do with a few crows maybe

[dizzykizzy]

Hmm, I think it will be prohibitively expensive to treat even the bad areas so will just have to hope the Winter sorts it out as others have said. Thanks for all your help 

[devonlady]

If you have so many crows they are probably rooks. MY dad taught us the old rule.....If you see a flock of crows they're rooks. If you see a rook on it's own it's a crow. Either way they are doing you a good turn, clearing your pasture of maggots. All will resolve itself over the winter.

[Buffy the eggs layer]

The chaffers come in different types. some with a 12 month life cycle some 3-4 years. You will need to harrow and reseed the area or the fine soil will offer a home to the adult females next year. If you spray the whole pasture now with Cyren or a similar product you will kill them all within about 24 hours. If you leave them they will continue to destroy the grass and then burrow deeper under ground to over winter. The cold wont kill them and the ones that emerge next year will be looking for a nice sandy spot to lay next years eggs. Killing them now will reduce the numbers visiting you next year.

[spandit]

Does sound like the crows are doing you a favour, even if it is unsightly for a while

[Steph Hen]

This was on gardeners question time, consensus was leave them too it. -they should stop in cold weather.

[dizzykizzy]

thanks all, going to leave and see what happens. We thought it was badgers 3/4 years ago when it happened, perhaps it was crows on the lifecycle someone suggested