I have noticed these last few morning more Robins singing, this is usually around 5:00 am when I am walking the dog before I go to work.

In one area of about 100 metres I heard at least five singing, this is usually birds declaring their winter territory as the UK population is increased by birds from mainland Europe that have migrated here to spend the winter.

The song in the Autumn is different from that sung in Spring when the males are attracting a mate, The Autumn song is more subdued and can often be heard late at night ( I once heard one at 1:00 am on new years day, my first bird spot of the year ), the spring song which can start as early as  late December is more powerful and lively.

Robin singing in Spring

At this time of Year the robins usually sing under street lamps, could it be they think this is the rising Sun?, research has shown that if it is a very cold night the robins will only sing if the have enough energy as they use most of their energy keeping warm, the robin can store fat for energy so if it has been a warm night they will have enough energy left to sing.

Gardeners may have noticed as they dig ground over in the Autumn and Winter they may have a robin at their feet, getting any worms exposed by the digging, this behaviour is linked to when the robin (which is a woodland bird) would follow wild boar and pigs as theY foraged in the leaf litter of the woodland floor.