Wiliamson's Weekly Nature Notes

In my photograph taken through the kitchen window is a marsh tit; in the painting by Philip Rickman is the willow tit.

Way back in 1900, a Sussex naturalist by the name of W R Butterfield determined to discover whether there was any difference. Excited rumours, you see, had emanated from South Kensington's Natural History Museum that not all marsh tits were marsh tits.

Messrs Hartert and Kleinschmidt had examined specimens from Middlesex. They found minute differences. The hunt was on. In August, Butterfield loaded his No 3 pop-gun with dust-shot and crept silently through the woods near St Leonards-on-Sea.

Pop after pop reverberated thro

ugh the leafy verdure. Down came the marsh tits one, two, three. Many more followed.

By December, he had several dozen marsh tits and at least half a dozen lookalikes. He skinned the lot. And off they went to the scientists in the museums.

A new British species was identified: Parus atricapillus Kleinschmidti. Today it is just called Parus montanus.

Although the willow tit lives with marsh tits in Sussex woods, it prefers the damper parts. It has a different nesting site too, and will often excavate a fresh, round hole, near the ground, in a dead, damp log, as shown by the artist in his picture here.

Marsh tits tend to nest in smaller crevices, higher up. How do you tell them apart otherwise? The marsh tit has a glossy cap, compared with a dull black cap on the willow. Not at all obvious that one.

The artist has taken particular care to show the pale grey edges to the secondary flight, or wing, feathers.

If anything, he has slightly over-egged that pudding but it puts this diagnostic feature firmly in your head.

Mainly though, nowadays, birders rely on the song in the few weeks following Valentine's Day. The repeated notes of the marsh tit are chip-chip-chip-chip. The willow tit is a deeper, fruitier, nightingale-like chu-chu-chu-chu.

It's not easy to do it by song but better than shooting.

This feature was first published in the West Sussex Gazette on March 12. To read it first see the West Sussex Gazette every Wednesday.