For the last ten years I have fed the birds in my suburban garden all the year round. The main food I put out is sunflower hearts which all species seem to like. Normally there are large numbers of gold and green finches, along with chaffinches, that are competing to get onto the feeders and suddenly, they have all vanished. As I am working from home I can see the feeders from my dining room table and, today, in the last 5 hours I have seen one goldfinch. I started feeding a new batch of sunflower hearts about ten days ago but there are still various species of tit feeding and the wood pigeons are happily cleaning up the leavings, so I am not inclined to think there is anything wrong with the food. I have spoken to the supplier and they assure me they have had no other such feedback. If anyone has any ideas or comments, please do let me know. Many thanks, in advance.