In article , Sacha
writes

It's very strange - not your increase but the decline here. As far as we
know, nothing has changed in terms of habitat or feeding or predators. The
only thing is the sparrowhawks but I really don't think they can account for
this drop in numbers.
Blackbirds are the most numerous and thrush the least.

Song thrushes have been declining over the years. We get mistle
thrushes, especially in the winter when they come for the holly berries
in the front garden, but it's rare for us to get a song thrush.

I don't count the
rooks because the rookery is in the garden and we can hardly fail to notice
those!

we don't get rooks ;-)

But we used to see dozens of bluetits and chaffinches.

Bluetits are insect eaters. I get them peeling the aphids of my
honeysuckle. But you're pesticide-free so you should have plenty of food
for them too.

It's a puzzle, because you've got plenty of space and variety there. Are
birds disappearing from the farmland around you? (This is a question,
not a judgement ;-) )

--
Kay
"Do not insult the crocodile until you have crossed the river"