July is when waterfowl, like Mallards, lose all of their flight feathers at once and so cannot fly. This would put the colourful males at risk from predators so they acquire an "eclipse" plumage that makes them look like females and offers better camouflage. Other garden birds will also soon start moulting and some, like the Robin, can be quite retiring.
After they have finished the exhausting job of rearing their young, adult birds start to replace their worn and faded feathers in a process called moulting. Also, in a few months, many of this year's juveniles will start to get their adult plumage and some species, like the Starling, can look very strange with some juvenile feathers and some adult ones.
Look out for moulted feathers and see if you can work out the bird from which they came. Also, take a very close look at the feather through a magnifying glass or microscope and you'll see the little hooks that hold the barbs together. Find out more