Friday, 1 April 2011

A difficult start

It has been something of an inauspicious start to the nesting season for some of our familiar species. Mid-March, the best time to pin down the intricate domed nests of Long-tailed Tits, had started well and we had found five pairs busy building within the space of a few hours. Two other pairs were behaving suspiciously, leaving tell-tale pointers as to where the nest was likely to be built over the coming days. A week later and three of the nests had been predated, most likely broken into by crows or other corvids. The three that were predated were all fairly exposed, perhaps because the vegetation has been slow to green up this spring as a result of the severe winter we have just come through.

That second visit also revealed another two nests and a suggestion of three other pairs we had yet to pin down. There was also a good chance that the birds who had failed so early, and almost certainly before laying any eggs, would have another go, so things may well get back on track. The question of whether the Long-tailed Tits will do as well as they did last year, when all our nests succeeded in raising young, is something that we will not be able to answer for a number of weeks.

The nests of Long-tailed Tits mark the start of the nest finding season for us, although there is always the odd pair of Robins or Blackbirds having a go in town. The tits are fairly easy to watch, and are readily located by their characteristic calls. Once you have found where they are it is simply a question of sitting and watching where they go and what they do. Sooner or later you will see them collecting and carrying nesting material to the chosen site, a site that is invariably well hidden in some thorny bush (ours tend to favour gorse at this time of the year). Once complete, and covered with lichen and spider webs, the nests are surprisingly well-camouflaged and difficult to spot.

Being completely enclosed, the nests are difficult to monitor and so we have recently invested in an endoscope (a miniature camera on the end of a flexible cable and attached to a hand-held monitor), which allows us to see inside the nest to count the eggs and chicks. Being able to monitor these nests, plus those of many other species, allows us to collect important information on productivity which can then be used to alert conservation bodies to any changes in breeding success that might give cause for concern. With just two to three hundred Long-tailed Tit nests monitored nationally our contribution is an important one.

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