Future studies
The London Biodiversity Partnership, the RSPB and the British Trust for
Ornithology are reviewing our current knowledge of house sparrows,
identifying the gaps and planning further studies. We greatly appreciate
the help that so many Londoners gave us in summer 2002 and look
forward to this support for future projects.
Thank you.
The LBP House Sparrow Action Group
Greater London Authority, London Wildlife Trust, London Natural
History Society, Birkbeck College, London Borough of Islington, City of
Westminster, London Biodiversity Partnership and the RSPB.
This report was produced by the
RSPB, The Lodge, Sandy,
Bedfordshire SG19 2DL
Regd charity no 207076
Cover & internal illustrations of
house sparrows by Mike Langman
Wpo/am/comms/WHATSparrow4.pub/3994
14
House sparrow by John Busby
Where have all our
sparrows gone?
Survey report
London, 2002
Thank you
Nearly 12,000 people filled in the survey forms on which this report is
based. All the organisers of the project would like to thank them sincerely
for their great response, and their concern and care for London’s birds.
How about a nestbox?
Make a simple box for
sparrows from a plank
about 150 mm wide and
15 mm thick – check the
diagram for details on
the size of each section to
be cut. The inside of the
box must be at least
100 mm square and the
bottom of the entrance
hole must be at least 125
mm from the floor. The
hole should be 32 mm
wide.
Use galvanised nails or
screws. Drill a drainage
hole in the base. Hinge
the lid with a strip of
leather or rubber (an old
piece of bicycle inner
tube is fine), and use a
good catch to fasten it:
you will want to clean
the box out in the
autumn. Treat softwood boxes with water-based preservatives, such as
Sadolin, applying only to the outside of the box, and not around the
entrance hole. Let the box dry and air thoroughly before putting it up.
Sparrows are sociable birds, so you could put up more than one box,
spaced a few metres apart. The box should be placed high enough to be
out of the reach of cats and people. Sparrows traditionally nest under the
eaves, so this would be a natural place to put your nestbox. It is best facing
between north and east, thus avoiding strong sunlight and the wettest
winds.
13
Regular feeding in winter helps birds
through the hardest times, and keeps
adult birds in better condition to cope
with bringing up their young in the
summer. Birds also need clean water
for drinking, and for bathing – an
important part of feather care.
You could make your garden – or
other green space – more wildlifefriendly.
Not using pesticides and
going organic is a good start; this will
improve the variety of plants and
animals. Sparrows eat the seeds of
many cultivated and wild plants – let
flowers go to seed for the birds. They
need to find great quantities of aphids,
caterpillars and other invertebrates to
raise their families. In choosing which
plants to grow, consider their
attraction to insects, and provision of
seeds and berries. Trees, shrubs and
hedges supply cover and a safe
passage from place to place. There is
plenty of advice available in books
and from conservation bodies, such as
the RSPB.
Sparrows will roost at night, and
socialise during the day, in sheltered
places such as ivy-covered walls, and
dense trees. Even in the centre of
London, there is room for green walls
or rooftop gardens, pleasant for
people and good for wildlife.
Nestboxes may be used for roosting as
well as nesting.
12
32 mm
150 mm
250 mm 200 mm
200 mm
250 mm
200 mm
212 mm
112 mm
450 mm
The survey in brief
• Nearly 12,000 people filled in ‘Where have all our sparrows gone?’
survey forms between 18 June and 19 July 2002, helping the London
Biodiversity Partnership to learn more about house sparrows in
Greater London
• They provided information about house sparrows at 9,172 homes and
3,698 other places in London – a great response and the biggest ever
participation in a study of a single bird species in the capital
• Reports of the highest number seen at one time in each site totalled
74,862 sparrows, just a sample of the whole population
• Maps of the presence of house sparrows reported from each borough
show that they were more common in outer areas than in the City and
West End
• House sparrows were noted at 73% of participants’ homes, varying
from 94% in Havering, and 93% in Barking and Dagenham, to 30% in
Camden, and 17% in Westminster
• The highest mean number of sparrows per home was 12 in Barking and
Dagenham; the lowest was 1 or 2 in Kensington and Chelsea, and
Westminster
• 32% of forms reported sparrows nesting, mostly in bushes and
hedges – 38% of nests, and in roofs – 36%
• House sparrows were more likely to nest in homes built before 1945
than in newer homes
• Sparrows are still holding on at many of London’s City Farms, even in
Inner London, with an average of 13 sparrows per farm
• The survey has provided much useful information and helped to raise
awareness of the plight of the ‘Cockney sparrer’, which is now on the
Red List of birds in the United Kingdom because its population has
declined by more than 50% in the last 25 years
• More analysis of the results is taking place and further studies are
planned. This survey will help to inspire and direct future action in
London and beyond.
1
Why study sparrows?
The house sparrow population is declining fast, both in London and most
parts of England. In London, the replacement of horse-drawn carriages by
motorised vehicles, and the resulting loss of spilled cereal as food for
sparrows, is thought to have contributed to a drop in numbers during the
first half of the last century. The downward trend has continued,
becoming especially severe during the 1990s. Between 1994 and 2000, the
Breeding Bird Survey (run by the British Trust for Ornithology, the Joint
Nature Conservation Committee and the RSPB) recorded a fall of 59% in
house sparrow numbers at sites in London. This year, because numbers
nationally have fallen by more than half in the last 25 years, the house
sparrow was placed on the ‘Red List’ of British birds, the species of
highest conservation concern. It may still be one of our more common and
widespread birds, but the steep decline is puzzling and worrying.
Of all British birds, the house sparrow perhaps lives closest to people.
Because it nests in our houses and accepts food from us, people generally
treat it with affection, as a friendly, chirpy character. We are concerned to
see a familiar bird disappearing, and it raises questions about the quality
of our shared environment.
To find the best ways of trying to restore the sparrows’ fortunes, we need
to know more about what is really happening and to identify the causes of
the decline.
The survey
The survey, ‘Where have all our sparrows gone?’, was carried out as part
of the Species Action Plan for house sparrows in the London Biodiversity
Action Plan. The Action Plan for sparrows is led by the Mayor of London.
We thank Awards for All, through London Wildlife Trust, for helping to
fund the survey and report, and London Natural History Society for a
donation.
The RSPB provided a large part of the funding and material support, and
the project was overseen by its London Sparrow Officer Keith Noble, and
Dr Mark Eaton, who analysed and produced the results reported here.
Survey forms were distributed to members of participating organisations,
2
Allotments were also good, with an average of 6.9 sparrows, while parks,
school playing fields, church grounds and cemeteries, garden squares and
even wildlife reserves averaged only around four or five sparrows.
Some studies seem to indicate that house sparrows can have trouble
finding enough food, such as insects to feed young and seeds for young
that have fledged. City farms will tend to have grain lying around from
the leftovers of farm animals, as well as rough weedy patches with an
abundance of naturally seeding herbs. Allotments, too, can be good
foraging habitat. The poorest category of site was workplace, with
sparrows present at just over half and an average of only three birds. A
wide variety of other places had sparrows, including golf courses,
riverbanks and towpaths, airports, market places, tennis clubs and even a
dry ski slope.
Some conclusions
This survey has told us many things about house sparrows in London. It
has confirmed our suspicions that sparrows are scarce in central areas;
numbers are higher in outer London, especially in the east. Gardens where
bird food is put out are more likely to have sparrows, and more of them,
although we cannot be sure that this is a direct effect of the food being
provided. Sparrows in London are most often found nesting in bushes/
shrubs and in roofs; nesting in the dwelling itself is slightly more frequent
in older buildings. They are also found in a wide variety of habitats away
from homes, with city farms and allotments being good ‘refuges’.
What can people do to help sparrows?
While conservationists are trying to pin down and address the chief
reasons for the decline of our house sparrow population, most people can
take some action to help sparrows and other wildlife. Providing food,
water, cover and breeding sites could make a difference.
Suitable food for sparrows includes seeds and grains, and products made
from them, such as bread and pastry. A range of different seed mixes and
feeders to hold them is now widely available. Moisten dry bread before
feeding – crumbling it up during the breeding season. Oatmeal mixed
with melted fat left from cooking is popular with birds.
11
There was a slight difference in the choice of sparrow nest site according
to the age of the property where they were breeding. Sparrows recorded
at older buildings were more likely to breed in the building itself (either in
the roof, a hole in the wall or in the chimney) than those at younger
properties (figure 6).
So it is possible that house sparrows may prefer to nest in homes, in the
holes, nooks and crannies they find, because they do so more frequently in
the (older) homes where more of these spaces are available.
Where else did people see house sparrows in London?
Many people also gave us information on sparrows they had seen away
from home; somewhere in London that they had visited during the survey
period. Of the 3,698 other places people told us about, sparrows were seen
at 74% and nests were reported at 12.1%.
Sparrows are still holding on at many of London’s city farms, even in
Inner London, with an average of 13 sparrows per farm. The Mudchute
City Farm in the Isle of Dogs held up to 50 sparrows – one of the largest
counts in the survey.
Figure 7. Occurrence of nesting sparrows away from homes
10
0
5
10
15
20
25
park
school grounds
playing field
garden square
church/cemetery
city farm
allotm
ent
wild space/nature reserve
workplace buildings
Place
% of returns where sparrows nesting
and to the public through libraries, museums, information offices and
many other outlets. The form could also be completed on participating
websites. The survey attracted plenty of attention from the media, not
only in London but as far as Australia, America and South Africa. We
greatly appreciate the support of everybody who made this a truly
popular project.
The results
Responses
We received 11,805 survey responses. Many were from people living
outside London who were keen to tell us about the sparrows where they
live – sadly we are unable to use these replies in this report, but we hope
to be able to look at house sparrows across the UK in the near future.
In London, we had 9,172 reports from homes and 3,698 from other places
where people had looked during the survey period – 18 June and 19 July
2002.
Where are the sparrows?
House sparrows were seen at 73% of participants’ homes. In all, 56,483
sparrows were reported from homes, with a further 18,379 reported from
the other places away from homes – a combined total of 74,862. The
average count of sparrows per home was 6.2 birds.
Although sparrows were found at 73% of participants’ homes in London
as a whole, there was considerable variation in occurrence between
different regions. The best boroughs were in the east of London. House
sparrows were present at 94% of homes in Havering, and 93% in Barking
and Dagenham*. Conversely, sparrows were very scarce in central areas,
with the City of Westminster being the poorest borough – sparrows were
seen at only 17% of participants’ homes.
* Footnote: all references to areas of London refer to the appropriate
London Borough
3
4
Percentage
83.5 to 94.4
72.5 to 83.5
61.5 to 72.5
50.5 to 61.5
28.5 to 39.5
17.5 to 28.5
The Figure 1 map, which shows for each borough the percentage of homes
where sparrows were reported present, clearly reveals this pattern. It
illustrates how scarce sparrows are in the heart of the capital.
As well as being found at more homes in outer London, house sparrows
were also found in greater numbers at these homes – a mean of 6.7
sparrows per home in outer London compared to 4.3 in inner London*.
The next map shows the number of sparrows per home at a finer scale –
each square is 2 km x 2 km tetrads – with the lighter colours in central
areas indicating fewer birds. Eastern areas were best; there was an average
of nearly 13 birds per home in Barking and Dagenham.
*Footnote: In this report ‘inner London’ is defined as including the
London Boroughs of Hammersmith and Fulham, Kensington and Chelsea,
City of Westminster, Camden, Haringey, Islington, City of London,
Figure 1. Map showing the percentage of homes where sparrows were
present
suggested that houses built recently are less likely to provide such
opportunities for nesting, and this could be making life harder for
sparrows. Participants were asked to give the age of the property they
were reporting from, in five age bands, so we could investigate the effect
of house age on whether sparrows nested, and if so where they chose to
nest.
The percentage of homes where sparrows were seen, the number seen,
and the percentage of homes where they nested all varied between
different home age categories. The average number of sparrows seen was
greatest in homes built between 1919 and 1944 (Figure 5).
The low numbers recorded in older properties built before 1919 is a
slightly surprising result. This result might be due to variation in the
surroundings of these buildings, rather than the suitability of the building
themselves for sparrows: perhaps, for example, pre-1919 buildings tend to
have smaller gardens or less surrounding green space. We are planning
further analysis to investigate this.
0
5
10
15
20
25
30
35
40
45
before 1919 1919-44 1945-64 1965-84 after 1984
Year property built
% of all sparrow nests in building itself
Figure 6. Effect of building age on proportion of sparrows nesting within
9
There were differences between London boroughs in the nesting sites
chosen by sparrows. For example, half of all nests reported from Barking
and Dagenham were in roofs, whereas in Camden less than a quarter were
in roofs. It seems likely that local differences, for example in the type of
housing stock, will affect where sparrows nest. There was no general
pattern in the choice of house sparrow nesting sites across London, with,
for example, no difference in the proportion of birds using ‘artificial’ sites
(roofs, chimneys, hole in walls, outbuildings and nestboxes) as opposed to
natural sites (ivy, bushes) between inner and outer London. Only in the
choice of two categories of nest site was there a real difference between
inner and outer London – sparrows were more likely to be found nesting
in ivy (or other creepers) and in holes in walls in inner London than in
outer London.
The effect of house age on house sparrow nesting sites
As the results above show, a significant proportion of London house
sparrows nest in ‘artificial’ sites such as chimneys and roofs, by finding
holes, nooks and crannies in houses and other buildings. It has been
0
1
2
3
4
5
6
7
8
Before 1919 1919-1944 1945-1964 1965-1984 After 1984
Date home was built
Average number of house sparrows seen
Figure 5. Average number of house sparrows seen at homes of different ages
8
Hackney, Tower Hamlets, Newham, Lewisham, Southwark, Lambeth and
Wandsworth. Outer London consists of the other 19 London boroughs.
How many sparrows are there?
Unfortunately, the results from our survey cannot be used to estimate the
number of house sparrows in the whole of London because we do not
know how representative the replies we received were of London homes
as a whole. For example, it is possible that people were more likely to send
a reply if they had sparrows rather than if they did not (therefore
sparrows may actually be present at less than 73% of all London homes).
We can be confident, however, that the total population is far in excess of
the 74,862 reported, as that total came from under 3% of the homes in
London.
Figure 2. Map of sparrow abundance by tetrad
5
Mean number of house sparrows
Of those participants that had not seen sparrows at their home during the
survey period, many told us when they last remembered seeing them.
Most (72%) had not seen sparrows around their home for over a year, but
this differed slightly between outer (78%) and inner London (70%).
This survey has provided valuable information on the whereabouts of
sparrows across London. We hope to conduct detailed analysis comparing
these results to environmental factors such as the availability of green
space, levels of various air pollutants and housing type in an attempt to
detect what may be governing the occurrence of house sparrows in
London.
What about bird-feeding?
The relationship was investigated between the number of sparrows
recorded and whether bird food was provided – participants were asked
whether they put food out for the birds, and at what time(s) of year.
Homes where food was provided had considerably more sparrows than
those where no food was put out (see figure 3). This may not simply be an
effect of this food attracting more of the local sparrows close to the home
to feed, as these properties were also more likely to have nesting
sparrows. Homes where food was only provided in the winter still had
more sparrows than those where no food was provided at any time of the
year, despite the fact that food was no longer being put out during the
0
1
2
3
4
5
6
7
8
All year Summer only Winter only Never
When food provided for birds
Average number of House Sparrows
Figure 3. Average number of house sparrows at homes with different
bird-feeding regimes
6
period of the survey. This may be due to winter-feeding increasing the
number of sparrows present at a home throughout the year. However, a
note of caution must be sounded about this interpretation. It may well be
that people who put food out for birds have larger or more wildlifefriendly
gardens (or indeed were more likely to have any sort of garden)
than those who did not.
Where do London sparrows nest?
Sparrows were reported as nesting by 32% of participants. As with counts
of birds, nesting was more frequent in outer London than inner London
where, for example, nests were reported from only 9% of homes in both
Westminster and Kensington and Chelsea.
Our survey forms asked people to tell us where sparrows were nesting,
giving eight choices. By far the most common nesting sites were in bushes
(38% of nests) or in roofs (36%). In reality, the proportion of sparrows
nesting in roofs may be much larger, as these nests are high up and so
more likely to be missed by survey participants. Ivy was also used
frequently (11%) but other nesting habitats were only occasionally used.
Nestboxes were used by only 1% of nesting sparrows; this low use was
more likely due to the scarcity of suitable nest boxes for sparrows, rather
than any unwillingness of the birds to use them.
roof space
36%
bush/shrub/hedge
38%
other
9% outbuilding/shed
1%
ivy/other creeper
11%
hole-in-wall
3%
chimney
1%
nestbox
1%
Figure 4. Choice of nest sites by house sparrows
7