These aren’t drawings of the birds’ ‘true’, accurate appearance – it would be easier to study a bird book for an authoritative version of that – but they aren’t drawings of the birds as I saw them either; they’re drawings of the way I remembered the
appearance of the bird after I’d looked at it for as long as possible, which wasn’t long enough, through binoculars.
This way of drawing varies from my normal approach where I look and look and look again, building up a drawing from dozens, probably hundreds, of little observations. 
That’s not an option with most of the birds in our garden. I took mental notes of shape and colour during my one lingering look at each bird and then tried to stick to that, rather than revert to the familiar picture of, say, a Blackbird, that I might already carry in my mind.
I gave myself license not to worry if the final drawing didn’t look all that much like the bird. As I say, I could have referred to a bird book if that had been my aim but these are the colours and the shapes, as accurately and honestly as I could transfer them 
from memory to paper.
The species I drew are male Chaffinch, Starling, female and male Blackbird, Great Tit and Woodpigeon. I used an ArtPen with brown Noodler’s waterproof ink and Cotman watercolours.
I particularly enjoyed this post. A favorite artist of mine, the 20C watercolorist, James Fitzgerald, would watch the seagulls from the rocks near his studio on Monhegan Island, Maine, then later return to his studio to paint them. These seagull paintings have an incredible, almost unique, vitality. He captured that feeling of being in the presence of those hovering, noisy scavengers through this very process.
Your mention of gulls and islands makes me realise that it’s time for me to get out to the coast again with my sketchbook! But at least I can always look out of the window at the garden birds.