Bird of the Month - Treecreeper
In the sixth instalment of our “Bird of the Month” blog we return to the wintery woods in search of a fairly common but hard to spot species.As November reaches its close, the last of the Autumn colour fades from Fingle Woods. Some years the leaves are ripped away by a fierce gale, others they fall gently, freed from the branches by a sharp frost. Either way, by early December the deciduous trees are bare, standing as silhouettes against the winter sky.Although many of the species which visit Fingle during the spring and summer are long gone, having flown south to spend the winter months in sub-Saharan Africa, the woods still provide valuable food and shelter for the year round residents. For an intrepid birdwatcher prepared to wrap up warm and head out to the woods, the bare trees make it much easier to spot some species which often prove hard to find when the leaves are growing.A good place to look for this month’s bird are the mature Oak and Beech trees which grow between the riverside track and the water’s edge. As you walk along, pay close attention to the trunks of the trees, looking for a shape moving across the bark. If you spot a small brown bird with a strikingly white breast making its way UP the trunk, you’ve probably found a Treecreeper (Certhia familiaris). Another species of similar habits is the Nuthatch, which has a slate-blue back and russet breast, and almost always travels DOWN the trunk – but that’s a bird for another month!Treecreeper are a fairly common species in the UK, and their ability to colonise urban parks and gardens with large trees has helped them escape significant declines over the last few decades. You might not think so, however, since their elusive nature means they are often under-recorded – it usually takes a careful search of an area over a period of several minutes to spot one if they’re present.If you have a pair of binoculars with you when you spot one it’s worth trying to get a good look, as seen up close they are very distinctive birds, totally adapted for their lifestyle. Long, curving claws allow them to grip smooth or rough bark with ease, while a long, stiff tail acts as a “prop” as they make their way up the trunk. During their annual moult in later summer and early autumn, Treecreeper lose their outer tail feathers first, retaining the central pair until the rest have regrown, thus ensuring they’re always able to use the rigid feathers for support whilst feeding. A slender, downcurved bill is ideal for rooting small invertebrates out of cracks and crevices. Their mottled brown plumage allows them to blend into the tree trunk, making them almost invisible as long as they remain still.Treecreeper are early breeders, with their courtship occurring throughout March and into early April. Their song is surprisingly melodic, a series of descending trills that sounds as though it might belong to a warbler species, but they sing very sporadically, with pauses of several minutes between each burst. Outside of the breeding season their call is a high, thin trill easily confused with the call of a Coal Tit or Goldfinch.Listen to a recording of Treecreeper song at Xeno CantoNot surprisingly, for a bird whose feeding habits are based around tree trunks, they nest there as well, picking a suitable crevice or the space behind a flaking plate of bark. A clutch of around 6 eggs will be laid in mid-April, and the female will remain on the nest to incubate them, while the male brings her food. The young will hatch after about two weeks, and will fledge a couple of weeks after that. Their early start to the breeding season often allows time for a second brood to be raised while suitable food sources are still available for the hatchlings.In the UK we only have a single resident species of Treecreeper, formally known as the Eurasian Treecreeper, but in Continental Europe a second species is also common, the Short-toed Treecreeper (Certhia brachydactyla). Interestingly, where both species are found together, the Short-toed prefers broadleaf woodland while the Eurasian is more often found in conifer forests. The fact that the UK birds are seldom found within conifer plantations is likely down to the relative recency of conifer as an available habitat in the southern part of the country, and the fact that commercial plantations seldom have a chance to develop features such as fissures and loose bark on which the species depends.As Fingle continues its gradual transition from commercial conifer forest back towards native broadleaf woodland, it is likely that some conifer stands and individual trees will be allowed to remain, eventually aging well beyond the point where they would normally be felled for timber. It will be interesting to see if these more mature specimens begin for provide feeding and roosting opportunities for Treecreeper, allowing this elusive but fascinating species to extend its range into new parts of the Fingle Woods site!If you would like to read the full 2020 Breeding Bird Survey report for Fingle Woods please click here.Text and pictures by Tom Williams
