The crabapple trees have been full of fruit for a couple of months now, but until a short time ago all the leaves were green. This week a few turned yellow — overnight, I swear, each affected leaf like a hair that went white in fright.
In the Great Auk, deciduous trees don’t produce an autumn exhibition like Canada’s or even the South Island’s. Still, our relatively slight alteration made me wonder: why do leaves change colour?
Several answers are at Discovery and a BBC nature blog: the yellow is carotene that’s already in the leaves but it only becomes evident when colder temperatures scare the pants off the green pigment involved with photosynthesis, chlorophyll. The red that’s seen in some trees’ leaves during autumn is more complicated.
These crabapples were planted for privacy a few years back. One has a distinctive lean to the right, though I can’t hold that against it. All three trees beckon me out the bay window of my room. They reach for the sky, and birds spend half the daylight hours in their branches.
Among them are quick little silvereyes. Their dexterity, their olive-green, grey and light tan colouring, and the bright eye-liner indicated by their common names (waxeye and white-eye too), make them very appealing. Here’s one photographed elsewhere by Steve Attwood, in Easter 2011.
Another bird drawn to the crabapples is a greenfinch, perhaps the first in our garden. He’s also small, but looks big and lumberly* beside the silvereyes.
One day I might be quick enough to catch them with my camera. For now, the sole documentary evidence of their presence is a picture of half-eaten fruit.
*lumberly, adj. Clumsy, cumbrous. OED.