Darren is outside in the garden, smoking. A very bad habit indeed, but it has its uses - he's hearing Redwings flying over in the dark!
I think many people associate hearing Redwings' high-pitched 'seeeep' calls with their southbound autumn migration. But tonight came as a reminder that they have to go back the other way, too.
I assumed previously that night migrants such as Redwings would pick a clear night to migrate, assuming that the stars help them plot a course, but this evening it's been drizzling heavily and the skies are 100% cloudy. How on earth are they managing to find their way?
Nobody seems quite sure.
I wonder if artificial lighting comes into it? When coming in to land at a British airport under cover of darkness, you can easily pick out street lights in built-up areas and along major routes, even from quite high up. The Europeans are much better at using energy-saving, light-pollution limiting lights.
Some links to interesting migration-themed features: