• Welcome to BirdForum, the internet's largest birding community with thousands of members from all over the world. The forums are dedicated to wild birds, birding, binoculars and equipment and all that goes with it.

    Please register for an account to take part in the discussions in the forum, post your pictures in the gallery and more.
ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

How many birds in UK? (1 Viewer)

sacha

Well-known member
A friend at work yesterday asked me that question. I thought he meant how many species, so I happily talked to him about UK records, regular visitors etc. But no, he meant How many individual birds!
And I realised I have no idea!!

Now I don't mean domestic fowl for which there seem to be figures online.

As there are apparently 65 million people in the UK... I estimate about 200 birds to every person when you include migrants and visitors, but is that a bad guess?

I believe there are figures of 3 million breeding woodpigeons?

Can anyone help with an answer?

Sacha
 
The answer would vary massively depending on the time of year. Think about early summer, when most of the migrants are already here, and most birds have produced young. The number of birds probably doubles and quadruples within a few weeks. As the season progresses and young birds get eaten, fly into windows, fall out of nests etc, the number will start to drop again. In late summer, the migrants disappear, later on winter visitors start appearing, and winter mortality starts taking its toll.

It's an interesting but quite impossible question - maybe somebody has had a go at working this out before. I think the answer is quite a lot though.

Mike
 
Quite a lot is the answer I came up with too haha. He asked me if it was more than people and I said, yes, without a doubt!

There was a figure online which showed a world estimate which I calculated as 200 times more than the world human population. Using this very rough world estimate it would mean that there are about 13 billion? Birds. Is that right or wrong? Sorry, my maths is rubbish!

But surely 200 to one is too much for the UK
 
Last edited:
The BTO website has population estimates for a lot of species here:
Breeding Birds of the Wider Countryside: Species List
Doesn't have every species, but I think all/most of the ones excluded are less common ones which don't contribute much to the overall total. Also excluded are ones which winter here, some in large numbers such as Fieldfare & Redwing, but don't have significant breeding populations here.

So, with a bit of effort you could go through the list and draw up a rough total for the number of breeding pairs. Obviously it wouldn't be perfect, but it should indicate whether 200 birds per person is a reaonable estimate or not.
 
I seem to remember many years ago reading that there were more birds in the British Isles in winter than at any other time - in terms of absolute numbers, that is individuals, rather than in number of species.

I don't know whether this was true then, or whether even if it were it is still the case.
 
I seem to remember many years ago reading that there were more birds in the British Isles in winter than at any other time - in terms of absolute numbers, that is individuals, rather than in number of species.

I don't know whether this was true then, or whether even if it were it is still the case.

That would make sense when you consider the huge number if wildfowl, waders, thrushes etc that winter. October would also presumably also include arriving wintering birds as well as passage migrants from Scandinavia and seabirds passing quickly through. Summer of course would include a few more seabirds and (the now decreasing) summer migrants.

Thank you also for the link above I will see if I can get an estimate!

Sacha
 
The numbers of wintering wildfowl are not that large , a few million ducks \ geese and around the same for waders , perhaps a little less at a guess. I would think the largest population is in late summer when large numbers of young birds are about.

I think some might be surprised how few birds there in the country compared to the human population. I would guess at maybe 4-5 birds to every person.
 
I think some might be surprised how few birds there in the country compared to the human population. I would guess at maybe 4-5 birds to every person.

I think you're right: so maybe 300 million birds (obviously it varies hugely over the 12 months as others have said); giving about 1,500 birds / sq km.
 
The numbers of wintering wildfowl are not that large , a few million ducks \ geese and around the same for waders , perhaps a little less at a guess. I would think the largest population is in late summer when large numbers of young birds are about.

I think some might be surprised how few birds there in the country compared to the human population. I would guess at maybe 4-5 birds to every person.

But is that guess based on anything?

How many birds in an average (or even below-average) garden? And how many people in the house attached to it - for one thing.

How many birds in an area of woodland? How many on a stretch of coast? A great deal more than the number of people resident in these areas.
 
Its a guess on a very rough knowlege of resident bird populations in this country.

Just to give a flavour below the average number of territorial males in the UK from the BTO. I have picked the most common Uk birds with populations of 1 million plus males. Though i may have missed a few species the majority of other species have populations way under 1 million males.

Blackbird 5m
Songthrush 1.4m
Robin 5m
Wren 8m
Blue Tit 3.5
Great Tit 2m
Willow warbler 2m
Whitethroat 1m
Blackcap 1m
Woodpigeon 3m
Skylark 1.7m
Chaffinch 5m

Thats 38 million males which we can turn into 77.2 million adults and this is on the high end as a small percentage of males will not have mates Averaging across the board
10 % nest losses gives us about 69 million adults . Given two broods of 8 young per pair that gives a population of 276 million young with a predation\loss rate of at least a third gives a late summer population of about 184 million plus say 50 million adults allowing for losses. So the above data gives a very rough total rounded up to say 234 million birds at the end of the summer and from then on the population will decline until the next breeding season. True we will have an influx of winter migrants but apart I think they would not exceed the late summer totals as summer migeants leave and preadation increases.
I have not the data to hand , but i would guess all the other UK species togeather does not exceed the above total so we are estimating about 468 million birds. I must add this is a best guess , but one based of BTO facts and information.


Just because you have a lot of birds in your garden do not think the population in the wider countryside in winter will be anyway near as high in density.
 
That still makes it about 7 birds to every human in the UK. Seems amazingly low but seems a far better estimate than my 200 to 1 !

It makes you realise that helping just the few birds in each garden is very important! If these figures were banded around conservation groups it would make people feel a bit more responsibility for 'their' 7 birds.

I only put this question out there to get an answer for my curious work colleague but there could be some serious use for the answer, not just in the UK.

If people are told about % decreases of Spotted Flycatcher populations, unless they are active birders like myself who SEE the decline, it is hard for them to understand how serious the decline is. If it is one of your 7 birds.. it feels much more personal.
 
Interesting thread.

This article from 2004 calculates the number of wild breeding (non-marine) birds in the UK to be 126,541,000 and number of humans to be 59,657,000, which works out as about 2 birds per person. Including non-breeding and wintering birds and marine birds would push that number up. The European average was 10 breeding birds/person. The highest figure was for Greenland with 188 breeding birds/person - due to a low human population I guess.

http://rspb.royalsocietypublishing.org/content/271/1548/1649.full.pdf+html.

They also make this statement "In the UK...the numbers of breeding wild birds is outnumbered by the numbers of chickens alone, and there is one
domestic cat for every 17 wild birds"
 
wow now this would get complicated.
1st you'd have to decide what time of year you are doing it on. once you have, get a list of every species in the UK at that time , find out their population numbers and add them all up.
 
As an aside, in Ian Newton's Bird Migration, he states that the number of European birds (of 186 species) that cross the Sahara each year at 3.5 billion.
 
As an aside, in Ian Newton's Bird Migration, he states that the number of European birds (of 186 species) that cross the Sahara each year at 3.5 billion.

So you can imagine how many millions of birds perish on that difficult stage of their migration.

Fascinating stuff....

So we seem to be reaching figures that average at around 2 birds per person at start of breeding season... then increasing to 3-4/ per person by summer and then decreasing steadily in the year with numbers supplemented by migrants and wintering birds...
 
So you can imagine how many millions of birds perish on that difficult stage of their migration.

Over a period of time long enough to average out the conditions met by migrants, the meaning of the much-misused term 'survival of the fittest' becomes abundantly clear. The cynical use of the term to describe what happens when birds encounter difficulties of human origin (eg industrial agriculture) as 'natural' is simply a way of obscuring the argument.
MJB
 
also of interest would be to do these calculations in biomass terms. i suspect human biomass will outweigh all bird biomass by a long way.
 
The authors of the paper I cited earlier calculated the relative biomass of birds to humans for Europe. 4 g of bird for every kg of human!
 
I think you're right: so maybe 300 million birds (obviously it varies hugely over the 12 months as others have said); giving about 1,500 birds / sq km.

My BBS square could contain 1,500 birds in Apr/May (when I do the survey), but I doubt it - my guess would be about 500. This is when bird numbers are at their lowest of course. And you have to take into account the vast areas of upland Britain that have very few.

The new Atlas will tell us ... be patient ...
 
Very interesting thread, I too have been asked that question before and had absolutely no idea of a total.
Some of the stats above really put things in perspective, firstly how each individual that helps/feeds birds can make a big difference. The other stat which is quite shocking is the fact that there are 17 birds to 1 domestic cat! How many birds does the average cat eat/play with in a year, 1 bird a month would not be difficult at all for some cats and some people have the audacity to blame Sparrowhawks for the decline of garden birds! (not that I want this thread to go there).
 
Warning! This thread is more than 13 years ago old.
It's likely that no further discussion is required, in which case we recommend starting a new thread. If however you feel your response is required you can still do so.

Users who are viewing this thread

Back
Top