English buzzard duck protection

[Mccluckers]

I have a very large 9x35m pen for my call ducks and I have lots of common buzzards and honey buzzards(in the us I think you refer to buzzards as vultures but in Europe they are actually medium-large Hawks. I can't afford a a net right now, so I am stringing bits of bailer twine across but I don't know how small to make the gaps

Any advice will be appreciated

 

[Mccluckers]

Anyone?

 

[Mccluckers]

So I've done some more twining today and so it is in strips 1ft apart, do you think I need to go the other way as well to make little squares?

Thanks