Urban noise 'killing baby house sparrows'

[microrobert]

Urban noise 'killing baby house sparrows'

http://news.bbcimg.co.uk/media/images/61485000/jpg/_61485971_sparrows400winney.jpg

The UK's house sparrow population has been declining since the 1970s


Noise in urban areas could be increasing the mortality rate among young house sparrows, a study has suggested.

Researchers say the noise could stop adult birds hearing the hunger calls from their dependent offspring.

In their study, the team found that birds nesting in noisy areas were less effective at feeding their chicks as those that nested in quieter places.

BBC News - Urban noise 'killing baby house sparrows' (http://www.bbc.co.uk/news/science-environment-18784607)

[kabeiros]

Sad... It seems I'm lucky to live in a small town, full of sparrows.

[Graham]

We have loads in the garden.

[Albion]

Utter rubbish, it's been known what the cause is for years and it isn't noise. Birds can be heard over most of the noise in towns such as cars and people.

The problem is that baby birds are starving to death. People think that they're doing good by leaving out bird seed (which they are), but this is no good for the babies. Baby song birds are typically raised on high protein insects and it is the lack of these which is the real cause of the decline.
And why are insects not as abundant in towns as they used to be? Well it's simple - we're too tidy. Grass isn't allowed to grow too tall, people pick up after their dogs (usually anyway) whilst wet and boggy areas have been drained - all these are perfect habitats for insects and they've been reduced in number.

The history of the house sparrow is really the history of humans. They are a native species but arguably wouldn't be in most of Europe if it wasn't for humans. House sparrows followed the spread of agriculture (the spread of grain) across Europe to Britain (before then the wood sparrow was the common species).
When people moved into towns during the industrial revolution the sparrows followed them. Although food and greenery was scarce, the sparrows soon found their source of sustenance - muck. Back during the industrial revolution horses were still common on British streets and they do not fully digest their food, with seeds and grain often being expelled in their droppings (which as anyone with horses knows is why weeds often grow from horse manure). The sparrows like many birds would sort through it and eat the seeds whilst the horse manure also acted as a breeding ground for flies and other insects, in turn feeding their young.

So it is because we're so tidy that we've inadvertently reduced the food source for house sparrows. Leaving out seed won't save the babies, arguably you'd be better leaving an area of mess - open up a compost heap and turn it over occasionally to let the insects escape, leave a few long areas of grass and perhaps a boggy area. Perhaps the easiest way of creating a little biodiversity hotspot is to dig a pond and fill it full of native aquatic plants. Ponds are a magnet for insects and in turn this helps support a healthy song bird and amphibian population.

It is important to note that house sparrows are dropping down to their pre-industrial revolution levels though. The countryside isn't as good a habitat as it used to be for them but still has a lot of grain and wet areas such as ponds, streams and puddles as well as long grass and overgrown areas for the insects. The populations in towns were in a way artificially high because of all the horses and all the mess. They have been in decline ever since horses disappeared from the streets and people started keeping the place tidy.