Nuthatches are an interesting little bird that will commonly come to feeders especially at this time of the year. I have a permanent hide and a feeding station next to a wood here in Exeter, Devon, UK. Nuthatches are one of the most common visitors at the feeders. At the feeders they can be aggressive to other small birds.
There will always be a dominant bird who will never allow another individual, not even other Nuthatches, on the feeder at the same time. When seen separately, the sexes are similar but males are more strongly marked and have brighter “brick-red” markings on the flanks. I like to watch them because they have an interesting peculiarity, they are the only British bird that will creep head first “down” a tree trunk or branch. The image above is a typical pose.
They will use their long strong beak to chisel in to nuts which they sometimes jam in to the cracks of bark to hold steady. They use existing holes in tree trunks for nesting and they will make the hole smaller by plastering mud around the hole. In the late summer I had the chance to see several newly fledged birds who were noticeably less brightly marked and had lightish coloured beaks and shorter tails than adults.