We tend to think of birds being very territorial when it comes to nesting. Blue Tits, we are told, have a nesting density of two pairs per acre: they space themselves out to ensure that there is enough food for them and their young.
But not all birds behave in this way. Some are highly sociable - examples being swifts and house martins. And sparrows.
Tree sparrows will form loose colonies, nesting in holes in trees or taking to nest boxes in undisturbed woodland. Their urban cousins, house sparrows, are also colony nesters but preferring human habitations as the site of their nests.
There has been a massive decline in UK house sparrow numbers recently with no single obvious cause. One of the factors may be the loss of the holes in old ill-fitting facias and soffits that have been replaced by ugly and ubiquitous upvc. When our neighbours at our previous house 'upgraded' to upvc, we lost the house sparrows.
There is a colony of house sparrows near to Cordwood - in the winter the birds gather in garrulous groups and their chirping can be heard some distance away. House sparrows like the cover of thick hedges and our local colony sometimes skulk in our privet hedge.
So, what better way to demonstrate our commitment to biodiversity than by erecting house sparrow colony boxes? Facing west and five metres high, three pairs can find accommodation here. Roger has included pull-out nest box bottoms so that the nest boxes can be cleaned.
To encourage the birds, we will need shrubs for them to hide in and we will need to encourage them to think our place is even more ideal by spending even more money on bird food. Fingers crossed for spring!