What about the tree sparrow?

Only about a dozen birds are thought to live in Sussex these days. Could you tell one from t'other?

I only ask because years ago I was caught out when a tree sparrow nested in the hedge in my garden at West Dean.

I had completely forgotten what the difference was, and had assumed I was looking at the nest of a common old house sparrow, the usual untidy bundle of straw and grass, copiously lined with feathers.

I was used to finding house sparrows' nests when I was a boy on our farm in Norfolk when the birds colonised thick ivy on the barn walls and trees around the yard.

Fifty years later when I came to live in West Dean I thought I recognised childhood habitats as they always had been.

Then someone said "It couldn't be a tree sparrow could it, since the nest is in what is almost a tree?"

Yes, my hedge as I optimistically call it, was a little overgrown and has now become a shelter belt swaying in the gales 40 feet up in the storm clouds.

Aghast at being caught out I rushed to the old Observer's Book of British Birds mother had given me for a birthday present when I was nine and there found the tree sparrow with its chocolate cap on its head.

The house sparrow has one of grey.

That was the most obvious ident, the little black cheek patch of the tree sparrow being less memorable.

Then I wondered how many tree sparrows I must have seen in my youth.

Perhaps not many, because though they were common from 1880-1935 they then went into a decline until 1960 which lasted for nearly two decades.

Nobody knows what causes these periodic highs and lows.

My research into population swings over 40 years here in West Sussex shows that most birds commonly go through wild ups and downs like a boat on the ocean waves.

So now the tree sparrow is at the bottom of a trough and we hope it will come out of that one day.

One problem it may have is that field weed seeds on which it feeds are now uncommon since farmers no longer have spring cereal sowings.

Back in the 1960s the vast cereal bred bin of Langford Farm at Lavant, for instance, with its winter stubble supported huge flocks of mixed finches, linnets, sparrows and buntings and there were tree sparrows amongst them, while hen harriers enjoyed the feast as well.

Even hares were more common then because the lactating does feed on young spring wheat and barley shoots.

So if you come across a flock of house sparrows around the village or the farm, see if any have a chocolate head.

The Sussex Bird Report published annually would like to hear from you.