In the Air, Cornwall Today
It may still be cold out there but day length is increasing and in the garden it is easy to see a change in emphasis in the behaviour of our resident birds. In place of the continual struggle to find food during the short days of winter robins, dunnocks, blackbirds and song thrushes now find enough time to spend the early morning in song. They are establishing their territory early in the year and will be laying eggs before the month’s end so that the arrival of their young will coincide with a plentiful time for food.
If April is to be the month for young-raising then March must be the month for nest-building and one bird species more than any other seems to relish the opportunity to collect nesting material, I refer to the house sparrow. The magpie may have the reputation for collecting the greatest variety of materials to add to its nest, showing a particular liking for shiny objects, but the house sparrow really should be better known for its desire to accumulate.
About ten years ago when we moved house we decided to put up terraces of nest boxes to provide the house sparrows with a place to live. They moved in immediately and started to fill the voids inside the boxes with material of their own choice. Cleaning out the nest boxes each year I get to have a good look at what it is they gather to keep them snug and it is almost exclusively pampas grass. I can’t blame them for specialising in collecting pampas grass, it is readily available in our garden and its seed heads take on their softest possible state in winter and early spring, just as the sparrows are creating their nests.
It always amazes me that house sparrows will not live in isolation, like us they choose to live in close proximity to others of their kind. Also like us they seem to bicker a lot with their neighbours and unusually I feel that I am being a little unfair on the human race by making this comparison because sparrows hardly ever stop squabbling! The one thing in their favour is that sparrow-squabbles can be entertaining. Many is the time I have sat inside the patio doors and watched as two male house sparrows have plummeted from the sky talons locked. They aren’t fighting over territory, they don’t need to, but the males can pick a fight about anything: food; nesting material and, of course, females.
At this time of year testosterone is coursing through the cock sparrow’s veins. To display the male sparrow’s vigour he is currently sporting a wonderful black bib but the development of this feature at this time of year is not the result of a moult as you might expect. Like many of our birds the house sparrow moults just once a year and that is in late summer. In order to provide better insulation to survive the winter the house sparrow’s new plumage is 70% heavier than the old feathers which it sheds. This in turn implies that during the year the house sparrow’s feathers must be worn down and this is exactly what happens. This abrasive effect has actually been utilised well by the sparrow because under the slightly dowdy plumage of winter is a colourful layer of feathers which, due to the tips of feathers gradually wearing away, come to the fore during spring. So during March the sparrow looks in tip top condition to attract potential mates but it is still wearing the same feathers as it wore last autumn and those with the greatest abrasion, probably the most active birds, will be sporting the largest black bibs and be most attractive to the opposite sex.
Right now the house sparrow needs our support, in some parts of the country its numbers are plummeting. The worst situation is in London and other major cities where the decline as been as much as 71% in the last few years. In Cornwall our house sparrows haven’t fared as badly but we should act now to help protect them. Putting up nest boxes is one helpful strategy. These boxes should be erected in groups under the eaves of our houses, a simple cube design with a hole of about one and a half inches is fine. Putting out bird seed in the garden will be useful to sparrows, other ideas to help them include: leaving a small area of uncultivated soil for them to dust bathe in during the summer; leaving fresh water for them to drink and bathe. You may think that I’m a bit mad but I also put out mesh bird feeders with a selection of suitable nesting materials in them; bits of fleece from our sheep or short lengths of wool; hair from horses, dogs or humans; feathers from old pillows. Obviously the most important ingredient for a successful sparrow colony is the availability of pampas grass, but I’m sure sparrows will take to other nesting materials where pampas grass isn’t on hand!