With a 40 million decline in the UK bird population since the 1970’s, the dawn chorus is not what it was, and we need to act now to prevent further loss of birds and wildlife. This was the message earlier this year from the RSPB, and it released a charity single Let Nature Sing, consisting entirely of birdsong, to publicise the message.

The single reached number 18 in the charts (not that anyone, even my teenage daughters, seems to care about the singles charts these days). It got me thinking about the birds I used to see in our garden or around Dulwich when we moved here 20 years or so ago, but which are no longer present. Sadly, the list is quite long.

House sparrows were in abundance back then but have now disappeared. Greenfinches would outmuscle the tits on the birdfeeder and a Chaffinch would pick up the pieces on the ground underneath. I have not spied either of these finches for several years. Song Thrush and Mistle Thrush would join the Blackbird on the lawn, now it’s just the Blackbird. House Martins would circle the big trees on the playing fields alongside the Swifts and nest in the eaves; the House Martins have gone, and while the Swifts are clinging on their numbers are clearly down. Collared Doves no longer accompany the Woodpigeons, and Starlings are a rarity nowadays.

So what has caused this decline, and what if anything can we do about it at the local level?

While loss of habitat, domestic cats and disease have played a part (disease almost certainly in the case of the Greenfinch), it is generally acknowledged that the decline of insects is the major factor. One of my abiding childhood memories is of my father washing down the front of the car and the windscreen to remove the dead flies after a long drive. No need to do that anymore.

Putting out bird food in our gardens is helpful, particularly to help adult birds through the winter, but does not solve the problem at breeding time that most nestlings need insects not seeds. To try and encourage more insects we can plant bee and butterfly friendly flowers and shrubs like lavender, buddleia, hebe, knapweed and foxglove to name but a few. We can keep a corner of the garden less tidy, go easier on the leaf blower and piling up some of the larger bits of dead wood to make a “bug hotel” rather than putting it all in the brown recycling bin.

Those who watched Springwatch this year know that the BBC have undertaken a Gardenwatch project, encouraging us all to log what wildlife we have in our gardens

currently, and do what we can to make our gardens that bit more wildlife friendly.

It is encouraging to see Southwark and the Estate letting some areas grow wild and creating new wildlife friendly areas such as the wonderful wildflower meadow in Dulwich Park and the new orchard by the Old Grammar School.

On the plus side there are some birds that are now regularly seen in Dulwich that were not here 20 years ago. Goldfinches are thriving in our gardens, thanks largely to the wide availability now of niger seed for our bird feeders. Jackdaws are back. We are all well aware of how well the Ring-necked Parakeets are doing - a mixed blessing given their screeching and propensity to hog some of the best nesting holes, but a colourful new addition, nonetheless.

Some of our old favourites seem to be doing as well as ever. Blue Tits and Great Tits abound, the Blackbird’s song continues to light up summer evenings, the Great Spotted Woodpecker seems firmly established as a garden bird now, and I am regularly woken up of a morning by the yaffle cry of a Green Woodpecker. There is still a lot of local wildlife to savour.

Let’s hope in another 20 years’ time I am not reminiscing about the days when we had blackbirds on the lawn, but rather I am thinking how good it is to have the song thrush back alongside them.