Wednesday, 27 February 2013

Spider webs, lichen and moss

A pair of long-tailed tits has been visiting the garden most mornings over the last fortnight. While the visits of long-tailed tits are not that unusual, the presence of just two birds at this time of year suggests that they are about to breed nearby. Long-tailed tits are one of the earliest species to set up home and late February is the time when you need to keep an eye on them if you want to find out where they are going to be nesting.

The nest itself is a beautiful construction, a dome of moss and hair, bound together with the silk from spider webs and then camouflaged with lichen. Placed within a thorny shrub or up against the trunk of a tree, the nest can be particularly difficult to spot once finished and it is far easier to locate its position while the birds are still building. During the period when the birds are prospecting they move about noisily, checking possible locations and you should soon be able to pin down the area they are likely to settle in.

Once building begins the birds may be seen carrying nesting material and they can then be watched back to the nest location. The build may take up to three weeks and during the latter stages, when the birds are collecting hundreds of feathers to make up the nest’s lining, the repeated visits quickly give away its location. The completed nest appears to be left for some time before it is then used and I sometimes wonder if the birds are testing to see if the activity of building has attracted the unwanted attention of potential nest predators. Long-tailed tit nests are often raided by members of the crow family, the ‘roof’ ripped off and the efforts of the parent birds torn apart to leave a ragged mess scattered across the vegetation. A curious feature of these nests is their elasticity, something clearly evident when you see a predated nest and the sheer volume of material that had been compacted into the space used.

With a bit of effort, the coming weeks should reveal a dozen or more long-tailed tit nests under construction on our local nature reserve. These also serve to signal the start of the nesting season when we, as nest recorders for the BTO, will be out and about charting the breeding attempts of these and many other species of bird. It often surprises people to discover that the breeding season proper begins so early but at least it begins gradually, giving you time to get your eye in and to work up to the busiest period in May and June, when resident breeders are joined by returning migrants.

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