A message from Barbara Johnson:
Where have all the blackbirds gone? Are they able to find enough food in the wild so don’t need to visit our gardens?
There are two possible reasons for the absence of your regular blackbird visitors, one specific to this drought-stricken year and the second more generally about blackbird behaviour. Lets begin with the second one first.
Blackbirds usually forage on the ground, rummaging among leaf litter for invertebrate food; the pictures here show one of the reserve’s blackbirds hunting among frosty fallen leaves in January. But come the autumn, their attention turns to berries and fruits.
Blackbirds are aggressively territorial; males establish a territory early in the year, as early as February in the south of England, and defend it with loud song and bellicose behaviour right through the breeding season and into autumn.
This territorial urge slackens in the autumn and winter. Nobody seems to be sure how the change in behaviour is triggered but its effect is to permit the year’s fledglings to spread out, to learn to forage for themselves, and to search for their own territories without the danger of constant bullying and badgering. It also allows (or even instructs – we don’t really know how these triggers work) the adult birds to leave their territories to take advantage of autumn’s crop of berries and fruit in the wider countryside
This year’s drought has changed the flora-timetable. Many less drought-tolerant trees, particularly the early flowerers, shed both their leaves and their fruit buds before the end of the summer to reduce their need for water. While some have developed a second flush of leaves, the possibility of a second crop of fruit is somewhere around nil.
Meanwhile, the trigger that changes the blackbirds’ behaviour and sends them out from their territories to feed among the autumn fruit seems to have worked just fine. But the foraging birds will have travelled much further this year from the feeding station in Barbara’s garden, and faced more and fiercer competition for what little fruit there is. There will have been losses.
So: it has been a bad year for fruit and this, in particular, is the time of year when normal blackbird behaviour sends them out to look for fruit. Perhaps the question isn’t where have all the blackbirds gone, but how many of them will come back.
Southwick Country Park Nature Reserve 
Thank you for your very comprehensive explanation. We usually have several blackbird here during the winter months. I’ll let you know if they come back as expected!