I had an enjoyable afternoon renovating a gloomy corner of a garden the other day. Some overhanging branches of a large sycamore tree in a neighbouring garden had been removed the year before and the space revealed made it clear how the nearby shrubs had been straining for light. A Rosa moyesii had leaned over and laid half of its tall stems over a Viburnum tinus, which was itself leaning over a variegated Photinia davidiana ‘Palette’. As I stood looking at it all and thinking about where to begin work, I spotted an old nest perched on top of the confused mass of stems. It was obviously old because there was grass growing out of the top, so I got it down for a closer look and was fascinated to discover that the original nest had been re-purposed, not once but twice.
The first nest looks like it was built by a blackbird (Turdus merula), which you can see from the size and the fact that it’s made of twigs and moss, with some mud lining the inside.
On top of the blackbird’s nest, a pigeon has made another nest and you can see the uncomfortable layer of twigs on which pigeons choose to raise their young. A closer look gives a possible reason for making a nest out of a thin layer of twigs – it is full of pigeon droppings which, presumably, would more easily fall though the gaps between loosely layered twigs, but here have fallen mainly into the blackbird’s nest.
Having reared its young, the pigeon abandons the nest and the handy container is spied by a mouse, who has used it to store the fleshy roots of Arrhenatherum tuberosum, also called bulbous oatgrass and known for being a pest plant of rural and arable land. I cannot think of any other way that so many bulbs of this grass can have found their way up into that nest, other than being moved by a mouse. In this case, it didn’t work out too well, because they sprouted before being eaten.
I’ve seen a similar, but more impressive, example of a mouse re-using a bird’s nest to store food. This picture shows an old nest piled high with holly berries, which I found in another garden.