|
Description:
The House Sparrow
is a small but sturdily built bird with a stout bill designed
for eating seeds. The overall appearance is somewhat scruffy
due to the loose nature of the plumage. Adult males are distinctive,
the crown and nape are grey and only the sides of the head
are brown. The black bib is wide and extends down onto the
chest. The back is warm brown, streaked with black but with
a few white wing feathers. In winter the bib is reduced and
the brown at the sides of the head becomes flecked with grey.
Adult females and juvenile birds of both sexes are typically
sandy brown in colour with brown and grey streaks on the back
and wings.
House Sparrows
make a wide range of chirping and chattering sounds; the courtship
song being rather unkindly described as ‘a monotonous
series of the [chirp] call note'.
Ecology & Behaviour:
The individual
territory of the male House Sparrow really only consists of
the nesting hole and a very small area around it. This is
defended vigorously and used as the ultimate come-on for the
female. She will judge the male by his vigorous behaviour
and also by his plumage. The black bib is the badge he uses
and this is very important for him. It seems that males with
small bibs can be induced to behave more boldly if they have
bigger and blacker bibs painted on them!
The normal nest
sites are holes in buildings but if these are not available
they regularly build untidy detached nests within ivy. These
are really very characteristic and show the House Sparrow’s
quite close relationship to the weaver birds which build similar
nests in the tropics.
The decline in
House Sparrows has been going on for several decades and there
appear to be different factors influencing rural and suburban
populations. Agricultural change, loss of nest sites and reduced
food availability appears to have influenced rural populations
but the factors behind the urban and suburban declines are
more difficult to isolate. This is one of the reasons why
the BTO has recently run a House Sparrow Appeal and is now
setting up research to look at the declines in more detail.
Garden BirdWatch links
A 'Focus On' article on the House
Sparrow appeared in issue 9 of the Bird
Table magazine. Garden BirdWatch participants can download
a copy of this article from the participant only pages.
Thanks to the generosity of people
supporting the BTO House Sparrow Appeal, the Garden BirdWatch
Team will be running survey work on House Sparrows in 2003/2004.
|