Little Egrets in the Garden

These birds are occasionally seen in my garden in Christchurch, Dorset and last year one made a visit on my BGBW day. It did not appear in the final count as there was no tick-box for it. I do have a stream which runs through the garden and the fish are probably the reason for its presence.  Are others seeing them in their gardens or is this a rarity? Should the RSPB keep up with new trends and include this lovely bird in the BGBW list?