If you see a bird clambering up a tree trunk or upside down along a branch, it will be one of three species: a great spotted woodpecker, a nuthatch or a treecreeper. These three very different birds have several things in common: they can all be found clambering around the trunk or branches of trees such as oaks; all have stiffened tail feathers which help them climb upwards on vertical surfaces, and long toes with claws that help them climb or cling; they all scavenge for food (seeds and insects) in the crevices of bark, probing the cracks with their specially adapted bills. All three species are quite common in mature broad-leaved woodland, and Exbury Gardens holds a good population of all three.
Early in February the woodpeckers can be heard drumming. This is their version of song, and they use it to mark out their territories. These handsome birds excavate their own nest hole and may reuse it in subsequent years. It's easy to tell the sexes apart, as only the male has the patch of scarlet on the back of the neck, as in this photograph. They lay about four to six eggs, and both parents help to incubate them. One less attractive fact about the woodpeckers is that they can (and do) predate both nest boxes or natural nests, and eat the young birds or feed them to their own fledglings.
Treecreepers are very small birds, speckled brown above and white below with a long, slender, down-curved bill for extracting insects and seeds from bark crevices. They look a bit like little mice as they work their way up the tree in a spiral around the trunk. Once they get to the top they fly down to the bottom of another tree rather than climbing down. Although quite common, they are rather inconspicuous and have a very high wispy song which is quite hard to notice. They nest in a cavity behind loose bark and often choose a tree such as a Wellingtonia if there are any available, as there are at Exbury.
Nuthatches are plump and agile little birds, greyish blue above and pinkish below, which can descend a tree trunk head first and hang upside down beneath a branch. They have a loud ringing call making them easy to locate, although they go quiet while nesting. They nest in holes, sometimes on the underside of a branch, or take over an old woodpecker hole, plastering mud around the entrance to reduce the size.