The sweet-singing blackbird is in decline - could climate change bring it back?

The weekend just gone saw the RSPB’s Big Garden Birdwatch take place, one of the longest-running and largest citizen science projects in the world, where half a million people across the country spend an hour counting the species they can see from their garden or balcony and submit the results.

It would be remiss of me, therefore, not to focus on a bird this week, and there is one species in particular that has been a constant companion over this winter.

Every year, we get a decent gathering of blackbirds in our garden feasting on the windblown apples and spearing the lawn for worms with their golden beaks, the colour of a Seville orange tart.

This year, we have had at least half a dozen each day and, as the weather has grown colder, they have drawn closer to our kitchen door – drinking from the bird bath we have kept free of ice by pouring kettle water over it each morning.

The flock is nearly all-male, save for one glossy brown female that evidently has her pick of the bunch. Unlike our other garden stalwarts this winter, such as sparrows and long-tailed tits, there is not much social interaction between blackbird flocks in general. Rather, they gather together before one lucky winner eventually pairs off with the female. Think of it as an avian Blind Date, but with more mealworms.

Male blackbirds have territories that can be as small as half an acre, but they will defend these for their entire lives. However, outside the breeding season, a state of armistice is declared and the birds will happily mingle.

Looking at the various males competing for the female’s attention, I wonder which one will be declared victor and where in our garden the pair might build their nest?

Robins are often seen as the archetypal winter bird, but I find the blackbird brings greater cheer. Its song is more melodious than the robin’s slightly scratchier solo. Listen out for it in early spring around 3pm, when males often join a chorus in full voice in defence of their territories. This is known as “the blackbird hour”.

Often, blackbirds will be the first to strike up at dawn and the last to serenade the dusk. My favourite time to hear them is just after fresh rainfall, when their song floats over the sodden grass. My mother-in-law sometimes says if she could only ever hear one bird sing again, it would be a blackbird, and I think I agree.

The birds have a good ear, too. Blackbirds hunt for earthworms by listening to the faintest of tremors beneath the soil. If you watch them for a while, you will notice the birds cocking their head to the ground to properly hear what lies beneath.

Sadly, since the Big Garden Birdwatch started in 1979, blackbirds have been in decline, as have many other species among our favourite visitors. Their numbers are down 46 per cent over the past four decades, although there is some good news: recent research suggests that blackbirds may well be a beneficiary of climate change as increasingly frost-free winters mean that they can more easily dig for worms.

Blackbirds usually have two to three broods, with an average clutch of three to five eggs in each one. So whichever male from my winter flock wins out, I hope there will be many more to come.

More natural wonders to watch out for: hazel catkins, flowering early