DECLINE IN SPARROWS – THE REASON?

This first appeared in on Bird Table News in 2009 but Kate’s 2007 findings could be  relevant today  –

 

Everyone knows the house sparrow but not many give it a second glance.  A detailed survey into sparrow breeding showed some reasons why urban sparrow numbers may be dropping.

I admire the sparrow.  I think, without realising it, I’ve seen at least one a day for the past 20 years.  I’ve taken this little sparrow for granted.

Yet it’s success is closely tied to our own.

Sparrows are thought to have spread across Europe from Africa at the time of Neolichic man!  So they have been connected to us through history.  What a story they would tell if they could speak.

Colonies of house sparrows that live near an isolated farm or on an island only seem to survive as long as man is there.  This ability they have to use what man provides enables them to have up to 3 broods a year.

Yet in some areas house sparrows are declining.  Farming methods have sometimes been blamed but this is not the complete picture.

Kate Vincent a student from Leicester’s University collected data about urban sparrows.

Kate is very dedicated.  In 2007 she studied 619 nest boxes in Leicester which she put up over the previous three years.

She found that in urban areas the second or third broods of chicks are dying  in the nest.    The reason for this is unknown but starvation or infection could be a cause.

In some places the number of deaths is so big that the population of the house sparrow is dropping.

One of the reasons could be that early and late broods do have different diets.  Spring chicks are fed on beetles and daddy longlegs.  The midsummer birds are fed on smaller insects like aphids.  Aphids are plant eating insects – so lets get planting!

When the chicks are born, when they are at their most vulnerable, they eat only insects   and if there are not enough insects they will die of starvation.

Kate’s research and survey is really  valuable. It is relevant today and does provides questions as well as answers.

 

Leave a Reply

Your email address will not be published. Required fields are marked *