You can’t take your eyes off it for a moment. I had a couple of days away this week, and returned to find the place unrecognisable. I left in one kind of winter, I returned in quite another. The first was cold and wet and required constant vigorous movement: bloody wintry today! Cold enough for you?

I returned, and the weather was much the same: but this was now a blackthorn winter. The hedges along the river walk had exploded into action: great white snowfalls and snowdrifts of blossom. This reckless and intrepid pioneer was on its way: winter for the rest of us, but for the blackthorn, spring has sprung.

The sap is rising. But it always seems that the precocious flowering of the blackthorn is accompanied by a regression of the seasons: a sudden vicious recapitulation of winter’s worst. The blackthorn blooming generally follows a false spring whose purpose seems to be to trick the unwary.

But the blackthorn annually rises to the challenge. “The country people call it ‘blackthorn winter’, and thus it has been called, I dare say, by all the inhabitants of this island, from generation to generation,” wrote William Cobbett more than a century and a half ago.

Mark your blackthorns, should you see one in bloom this weekend, because in the autumn, the blackthorn bears sloes. Gather them in late September or early October, prick each one with a skewer, add to a bottle of gin and drink at Christmas. Some say the drink is better for being stored in the back of a car: the vibration aids the mutual absorption of flavours. Richard Mabey, in the indispensable Flora Britannica, recommends that, having drunk the liquid, “the pitted, gin-soaked sloes can be dipped into melted chocolate, which is then allowed to set.”

– The exceptional always catches the eye, in humans and in animals. Yesterday morning I saw a squirrel on a tree trunk, low down, wagging its tail furiously. This was not tail as balancing pole, this was tail as signalling device, sending a message of frantic excitement. The animal was beside itself. It ascended the tree, wagging with every leap, and then vanished.

When any animal does something spectacular and peculiar, the first and most likely possibility is sex. The second is aggression. It was a beautiful thing, this wagging tail, like the hand of a Balinese dancer, only furry. Rum thing, in the wild world, sex, aggression and beauty are frequently indistinguishable.

In John Steinbeck’s novel Cannery Row, the wise-and-foolish hero Doc is asked why stink-bugs stick their backsides up in the air. He answers that it’s probably because they’re praying: that any time any living thing does anything inexplicable, it’s probably for that reason. I think Doc was having us on: I’ll bet my life that that squirrel was not praying. He looked horny as hell to me. Inexplicable deeds far more often come back to sex: with or without aggression and beauty. As a bird sings, so a squirrel wags.

– As I walked out yesterday morning, the viciousness of the blackthorn winter had eased off and provoked a frenzy of song, in particular, a duet, loud and gorgeous from two thrushes, but of different species. In the garden, high on a treetop, a song thrush sang his song: a pattern of repeated phrases and improvisations, full of variation, often with sounds borrowed from the world around and elaborated on.

Across the field, a mistle thrush sang a wild and skirling song, a song that seems to have both the demented optimism and the underlying melancholy of the early spring. These two birds aren’t rivals: they live side by side without great conflict. They certainly don’t seek each other’s females. And yet that morning they seemed to be singing in response to each other, an English country antiphon.

Unprovable, but the two birds seemed to be getting encouragement from each other’s effort. Both respond to the turning of the year and to the sudden leap in temperature. But this seemed to me to be more than a coincidental response to the same stimuli. The birds were also responding to each other’s singing.

If they were competing, it was not competition for the same biological resources. I have a suspicion that what they were responding to most vividly was song itself: the delight in making music, a joyous jam session of thrush music. After all, joy in nature is not confined to human observers.

Times Recommends

• Snow brings out the inner Tory in all of us
• Hail, Britain’s Indiana Jones of the Amazon
• Hewitt and Hoon – two rabbits, one hat