Overwinter Population Estimates of British Waterbirds

Black-tailed Godwit by Andy Musgrove

Black-tailed Godwit by Andy Musgrove

Overwintering waterbirds constitute one of the most distinctive and significant elements of the British avifauna.

Very high proportions of many populations move to Britain for at least part of the non-breeding season. Estimates of the numbers of birds involved are important for conservation, both for status assessments and for the identification and designation of nationally and internationally important sites.

Monitoring waterbirds in Britain is typically undertaken by collating sample counts (mostly collected via WeBS – the Wetland Bird Survey) to derive inter-annual population trends. However, there are cases where it is necessary to know not just relative numbers, but population sizes. Given the need to work with reasonably up-to-date estimates, and given that many species are showing clear changes in recent status in Britain, a new analysis was carried out for all waterbirds present in Britain in winter. This work is fully detailed in a paper published in the journal British Birds in July 2011, with methods explained and discussion of each individual species or population estimate. The new estimates for wintering waterbirds in Britain are tabulated at the bottom of this page.  

 

Key recommendations arising from the production of the estimates are:

  1. For the conservation of the important over-wintering waterbirds in Britain, the highest priority is to maintain and, where possible, enhance the core monitoring schemes such as WeBS, GSMP, NEWS and WinGS.
  2. It is important to continue to develop methods of estimating the numbers of waterbirds in the wider countryside (i.e. on smaller still waters, rivers and other suitable habitat) away from the larger wetlands that are regularly counted for WeBS.
  3. New methods and surveys, or new data from less traditional sources such as bird ringers or hunters, are also need for species not easily estimated through direct counts, such as the snipes and Water Rail.
  4. Understanding the numbers of birds passing through Britain in spring and autumn is also important and studies to determine the degree of turnover should be further developed, especially using emerging technologies.
  5. There is much still to be learnt about the relative numbers and distributions of different biogeographical populations of a number of species, and more work would certainly be valuable in this area. 

 

English name
Estimate
English name
Estimate
Mute Swan
74,000
Great Cormorant
35,000
Bewick's Swan
7,000
Shag
110,000
Whooper Swan
11,000
Eurasian Bittern
600
Taiga Bean Goose
410
Little Egret
4,500
Tundra Bean Goose
320
Grey Heron
61,000
Pink-footed Goose
360,000
Eurasian Spoonbill
20
European White-fronted Goose
2,400
Moorhen
320,000
Greenland White-fronted Goose
13,000
Common Coot
180,000
Icelandic Greylag Goose
85,000
Oystercatcher
320,000
British Greylag Goose
140,000
Avocet
7,500
Snow Goose
180
Ringed Plover
34,000
Canada Goose
190,000
European Golden Plover
400,000
Greenland Barnacle Goose
58,000
Grey Plover
43,000
Svalbard Barnacle Goose
33,000
Northern Lapwing
620,000
Naturalised Barnacle Goose
2,700
Red Knot
320,000
Dark-bellied Brent Goose
91,000
Sanderling
16,000
Canadian Light-bellied Brent Goose
710
Little Stint
14
East Atlantic Light-bellied Brent Goose
3,400
Purple Sandpiper
13,000
Egyptian Goose
3,400
Dunlin
350,000
Common Shelduck
61,000
Ruff
800
Mandarin Duck
7,000
Jack Snipe
100,000
Eurasian Wigeon
440,000
Common Snipe
1,000,000
Gadwall
25,000
Woodcock
1,400,000
Eurasian Teal
210,000
Black-tailed Godwit
43,000
Mallard
680,000
Bar-tailed Godwit
38,000
Pintail
29,000
Whimbrel
30
Shoveler
18,000
Eurasian Curlew
140,000
Red-crested Pochard
320
Common Sandpiper
73
Common Pochard
38,000
Green Sandpiper
910
Tufted Duck
110,000
Spotted Redshank
98
Greater Scaup
5,200
Greenshank
610
Common Eider
55,000
Common Redshank
120,000
Shetland Common Eider
5,500
Turnstone
48,000
Long-tailed Duck
11,000
Mediterranean Gull
1,800
Common Scoter
100,000
Common Gull
700,000
Velvet Scoter
2,500
Caspian Gull
90
Common Goldeneye
20,000
Lesser Black-backed Gull
120,000
Smew
180
Glaucous Gull
150
Red-breasted Merganser
8,400
Iceland Gull
210
Goosander
12,000
Yellow-legged Gull
1,100
Ruddy Duck
90
Herring Gull
730,000
Red-throated Diver
17,000
Great Black-backed Gull
76,000
Black-throated Diver
560
Black-headed Gull
2,200,000
Great Northern Diver
2,500
 
 
Little Grebe
16,000
 
 
Great Crested Grebe
19,000
 
 
Red-necked Grebe
55
 
 
Slavonian Grebe
1,100
 
 
Black-necked Grebe
130
 
 

 

Citation: Musgrove, A.J., Austin, G.E., Hearn, R.D, Holt, C.A., Stroud, D.A. & Wotton, S.R. 2011. Overwinter population estimates of British waterbirds. British Birds, 104, pp 364-397.