The theory is to try to estimate what proportion of a habitat in the tetrad you covered and then pro-rata it up. I've not done it for mine yet, I'll wait until after the 2nd winter TTV and try to make a stab.
On the other hand, for example, if all your BHGs and Pied Wags were at EBSW, chances are your figure is the total for the tetrad.
Remember - they are only after very approximate figures.
Just to add to what Jim says. If you are not sure you can give a reasonable approximation the BTO says not to worry about it giving them. Just the details you have collated will suffice.
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Thanks folks. I think i will go along with Jim and have a stab at it later. It wasn't an altogether serious question, but it is nice to know you are out there to help. Cheers, Ina
