In winter, at least here in York, we seem to find the Greenfinches and Goldfinches form one large, though transient, flock. There can be as many as thirty or forty birds some days, other times it may just be a half dozen.
The availability of food in gardens was a boon to birds like the Greenfinch, and through the 1990s and early 2000s their numbers increased substantially. However in recent years they have started to decline again, as much as 50% in less than a decade, prompted in large part by a disease called trichomonosis. It is an unpleasant infection that stops the birds feeding, meaning they slowly starve. One of the simplest defences is to ensure you clean your bird feeders as regularly as you possibly can.
In my experience, Greenfinches rarely play well with others. They will see off any smaller finches, other families of Greenfinches, and even within a family group the ‘pecking order’ may be strictly observed and enforced.
On the positive side, their descending, slightly wheezy, call from the tops of trees is distinctive and evocative. We must hope a disease doesn’t remove that from the auditory pallet of the UK.
Sorry for the late arrival of this week’s BotW, I forgot to add the pictures so delayed it till I had chance to fix!