the bird droppings that are not.
Then I realised that virtually every leaf had the same mark. What a talented bird, I thought. So consistent. Of course the penny dropped quickly enough and I deduced they are leaf mines. As they are on Holly, Ilex aquifolium, I looked up Holly in my book on Micro Moths but failed to find anything similar.
By the wonder of googling “leaf mine holly” I unearthed a creature called rather unoriginally “Holly Leaf Miner”. And it is not a moth but a fly, Phytomyza ilicis. Diptera not Lepidoptera. I shall have to wait until June to see a fly emerge. I can hardly wait.