I mistake an ash tree full of starlings for an ash tree full of sodden bunches of ash keys (“Don’t those damp ash keys look a bit like… Oh”). I’m often wrong about things. I sit in our park, in the shadow of the steep wooded glen, and think about what I know and how I know it.
Most of the birds here occupy a different stratum of the park to me and the other parents pushing pushchairs, the kids on scooters, the couples lockdown-dating on benches, the path-pounding joggers. For the birds the park is a network of treetops – mostly evergreens, rich in cones and yew berries – with a lot of awkward open space in between.
Thrushes, tits, chaffinches, goldcrests. Watching them scud from one tree to another as if on zipwires, I’m struck by how readily my brain – or the part of it that’s been steeped in bird books for 30-odd years – tells them apart by size. It feels a bit like the way your fingers recognise coins in your pocket. Thrush shapes rank upward from redwing to mistle thrush (no burly fieldfares here yet); another scale runs from goldcrest to great tit – anything smaller than a goldcrest is most likely a windblown birch leaf.
It’s just as well that I can identify at least a few of them en route, because they’re adept, once they’ve landed, at burying themselves within the deep dark greens of the hollies, yews and pines. Half watching, I’ll catch a chaffinch’s wing bar, the eyeliner streak of a nuthatch, a long-tailed tit’s swivelling tail.
Today throws up a surprise – I think. From within a gallery of yew branches a finch’s head is briefly lifted, the plumage an imperfect sort of green, textured, almost scaly-looking. Crossbill? Could be – crossbills are very much on the move right now. I didn’t get a good view of its beak (crossed mandibles are a clinching ID point, leaving you only with the question – a doddle! – of telling apart the near-identical common, parrot and Scottish varieties).
I don’t see it again. I’ll never know for sure whether it was a crossbill or not (an ill-kempt greenfinch, a wintering siskin?). I’m better at dealing with this knowledge, with the birder’s known unknowns, than I used to be.