Sunday, 16 May 2010

silent spring?

An early memory from my childhood was of house martins (urbica delichon), chattering in the sky and building their mud nests against the eaves of houses.

The house martin is a black and white cousin of the swallow in the hirundine family. They migrate to Britain from Africa each spring and return in the autumn. Their arduous migration flight takes them over the African desserts. House martins feed on insects they catch on the wing and their crackling calls have been a feature of my summers since moving to Wilford, by Nottingham's River Trent nearly fifty years ago.

In Wilford they were abundant, building so many mud nests on walls that some residents considered them to be a pest and went to great lengths to knock the nests down. I was always scandalised by this behaviour, considering house martins to be exceptional additions to the birds of the summer.

On moving to our house near Mansfield twenty five years ago, I was delighted to find that house martins were abundant here too. I remember counting forty basking in the afternoon sun on the roof of a house opposite as they built their strength for a long return flight to Africa.

We were especially blessed because we had a nest on the wall by the kitchen and could hear the chattering and squabbling of the adult birds as they went about rebuilding their nests each spring. Our children were almost as excited as I was when the first flimsy egg shells slipped to the ground, showing that an egg had hatched.

We learned, through our years as neighbours, a lot about each other I'm sure. We learned what tough characters they could be on returning in spring and finding their nest occupied by house sparrows (passer domesticus). The sparrows did not go quietly but were always evicted!

We learned too that although house martins are colony nesting birds with several nests in a locality, it was not all peace and harmony in martin world.

It was distressing, for instance to find baby house martins thrown to their deaths by rival birds, presumably siblings or relatives of the parent birds in disputes about nest sites.

Steadily, the number of house martins has declined in this area. Last year I heard martins but did not see any nests at all. Nottinghamshire Birdwatchers reports reflect this decline.

The reasons foor the decline are not fully understood but may be linked to the growing size of the Sahara that the birds need to fly over twice each year in migration. It may also be due to changing agricultural practices resulting in fewer insects for the birds to feed on.

The inevitable consequence of this steady fall in numbers can be heard ( or not heard) in the garden. Where once house martins would be circling throughout the day, swooping between houses and forming loose flocks of two dozen birds in the evening sky, there is now nothing. Not a single house martin has returned to our area yet.

All may not be lost. This has been a very late spring: dead bees and wasps can be seen on the ground suggesting starvation. The birds may be waiting for warmer weather before coming home. I hope so. The English summer will be the poorer for their absence.

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