Return of the thrush?

"Extremely common everywhere, frequenting our gardens and shrubberies, and when the time comes taking heavy toll from fruits of all kinds." Those were the words of William Borrer to describe the Song Thrush in his 1891 book, "The Birds of Sussex".

I was privileged to edit the 2014 tome of the same name, for which the Song Thrush entry starts, "It has been a source of great sorrow for many that Song Thrushes are seen so much less frequently than previously." A rapid decline of the Song Thrush national population began in the 1970s, with numbers halving within the space of little more than a decade.

So, despite everything I am doing in my garden to make it fit for wildlife, there have been no Song Thrushes here throughout the summer. It was therefore with a hearty cheer when I heard the short little 'stip' call this week that announced that one had returned. It is one of those sounds that is very easy to overlook, it is so timid and understated, and is easy to mistake  for the 'hic' of the Blackbird, but it is one of those sounds that you can learn with practice.

What a fine looking bird it is, despite it having no bright colours on show. See how the spots on its breasts are like rounded chevrons, unlike the oval spots of its cousin, the Mistle Thrush. You can also see that the upper breast has a warm, fawny base-colour, melding into the white belly.

The reasons for the species' decline in the UK are not known for sure, but appear to be a mix of factors including changes in farmland management, use of pesticides and drainage of land, reducing the availability of food.

After the big declines in the 70s and 80s, numbers flattened out at the much lower level, and bobbled along for a couple of decades, but in the last five years or so have shown a little bit of a welcome increase. Has the corner been turned for the Song Thrush?

Well, it is possible that the milder winters are helping it survive, for it is largely a resident bird or short-distance migrant, and so is at the mercy of the weather. As Borrer said in 1891, "It seems to be one of the earliest resident birds to be affected by the cold, and is frequently found dead on a sudden accession of frost".

However, for us gardeners there is a worrying detail to report. Of all the habitats monitored by the BTO in the Breeding Bird Survey, it is in urban habitats that the Song Thrush is doing worst, and where its numbers continue to fall.

What can we do to help? Well, they are not the most regular visitor to bird tables, so this is where good wildlife-friendly gardening comes into play. Song Thrushes are well known for eating snails by smashing them on a 'thrush's anvil', so not seeking to eradicate your snail population is going to help. But perhaps even more important than that are planting berry-rich shrubs and hedges, and ensuring the garden has plenty of places where they can hunt their beloved worms.

Although worm-killing chemicals are not now available in the UK (it now seems shocking to think they once were), you can still find 'worm deterrents' on sale which are mainly chemicals designed to reduce the pH of the lawn soil and hence make the conditions unsuitable for them. These are marketed as helping you achieve the 'perfect lawn' because it means you don't get worm casts of the surface. To me, a lawn without worms is a sad place, and a very long way from perfect! Those worm casts are so easy to brush in, and show that worms are helping aerate the soil to the benefit of the lawn.

Hopefully, with wildlife-friendly gardening becoming more and more mainstream, we can one day all welcome the Song Thrush back into our gardens.