Nesting time
As milder weather returns, birds begin gathering nest material in the garden - small twigs, bits of grass, or pulling moss from the lawn. Blue and great tits can use a prodigious volume of moss for the foundations of their nests, especially if it’s in a large nest box. Blackbirds and thrushes weave grass and fine twiglets into a cup shape before lining it with grass, in the case of the blackbird, or a layer of mud (there’s no shortage of that) if it’s a song thrush. How thrushes do it without plastering themselves with mud I don’t know!
What I find truly remarkable is the construction skills of the pair of crows who have nested right at the tip of a mature chestnut tree in our garden for almost ten years. On the top of the ridge, the crown of this tree is rarely still for long, yet our two intrepid builders managed to construct a nest of sturdy twigs that has stood the test of time, needing only an annual bit of DIY to knock it into shape again for each new clutch. But how did they manage to get the very first twig to stay put while they went off to collect the subsequent ones?
We’ve named our pair Russel and Sheryl Crow. I doubt it’s the same pair after ten years, but every summer they, or their successors, have managed to fledge young. It’s fascinating to watch their courtship as it’s about the only time you can work out who is Russel and who is Sheryl. Sexes are identical, so can only be told apart in the breeding season. Males are slightly larger than females, but to use that method you need to catch them to take the measurements of wings, legs and depth of bill. That’s not easy - I’ve tried setting a special trap, but they are always one step ahead of me!
So, for yet another year, I will have to study them closely while eating my breakfast, hoping to catch the moment when their behaviour will demonstrate who is who. Not that it will be a lot of good as, being identical in appearance, as soon as they separate, I’ll be none the wiser again!
Returning to the tits. I’m often asked if it’s helpful to put out nest material for them. It’s something I did for many years, until I started to check the progress of nesting attempts of swallows in stables. They made use of the plentiful horsehair to line their nests and it was not unusual to find chicks tangled in it. On two occasions when a brood had fledged, I found a pathetic corpse hanging by its neck on horsehair. Tits in nests with sheep’s wool can also get entangled. So, I leave nature to its own devices. If birds can’t find enough nesting material in your garden or nearby, they almost certainly won’t be able to find enough food for their chicks.
Fortunately, Russel and Sheryl make do with leaves.