I can't find it right now. However, a few years ago there was a nice study in
Journal of Ornithology comparing the population of House Sparrows in Hamburg
(HH) and Berlin (B), Germany. They showed that the population in HH decreased
much faster than in B. Reasons were (from what I remember):
1. Loss of nesting habitat, especially under roofs (HH is much quicker in
fixing holes and openings in buildings than B)
2. Decline of food sources (decline in traditional stock breeding, "cleaner"
agricultural methods, pesticides, decrease in nature-like gardens and parks;
the landscape in B is much more heterogenous than in HH)
3. Loss of dust bathing habitat (sandy spots/dirt roads; B has an advantage
there as well: lots of large construction sites)
Nikolas
----------------
Nikolas Haass
Sydney, NSW
----- Original Message ----
From: Rosemary Royle <>
To: Syd Curtis <>; bird <>
Sent: Thursday, June 26, 2008 7:09:26 PM
Subject: Re: [Birding-Aus] Sparrows
I am fascinated that House Sparrows are becoming scarce in urban areas in
Australia, just like they are in the UK. They seem OK here in rural areas and
are even increasing in some of these (e.g. Scotland, Wales)
If the House Sparrows are disappearing you can't help but wonder whether the
cause must not also be affecting the humans. The favourite theory in the UK is
that there are no insects in urban areas any more for the sparrows to feed to
their young - which is true. (There are some staggering figures around about
the decrease in moth densities over the last 50 years and you never see a fly
in a town these days). But why are there no insects?? Traffic fumes maybe?
Which also may cause the virtual asthma epidemic in children? Or just not
enough habitat for insects to thrive? There is a huge amount of research going
on and a guess the answers will emerge soon.
As one of the previous correspondents said, House Sparrows may simply be
returning to sensible levels after a super-abundance in the early 1900s caused
by untidy agriculture and in London, certainly, by the use of horse-drawn
vehicles and the attendant oats.
Perhaps, at heart, they are a bird of untidy,scruffy and developing cities and
just fade away when there is too much concrete.
Rosemary Royle
Wales, UK
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