Open Access
How to translate text using browser tools
1 December 2001 The Decline of the Bullfinch Pyrrhula pyrrhula in Britain: is the Mechanism Known?
Gavin M. Siriwardena, Stephen N. Freeman, Humphrey Q. P. Crick
Author Affiliations +
Abstract

The Bullfinch has declined in Britain and elsewhere in Europe, but definitive evidence about the cause and demographic mechanism has yet to be published. We review current knowledge, concentrating on analyses of demography, and present new integrated population modelling analyses designed to reveal the demographic changes most important in the decline. It is likely that changes in brood size and clutch size have not been important and our models suggest that the decline can be explained without invoking variation in numbers of breeding attempts or post-fledging survival rates. However, although changes in the egg period daily nest failure rate provide the best explanation for population change during the years of steepest decline, nestling period failures, adult survival and first-year survival could all have been equally important. Egg period nest failure rates have been higher in the preferred habitat, woodland, than in farmland and have fallen over time in farmland, where a larger decline has occurred (65 % versus 28% ), arguing against a causal link with abundance. Despite evidence for a negative effect of agricultural intensification on Bullfinch presence, little evidence exists clearly linking any demographic rate to environmental change and agricultural land-use has had little effect on nest failure rates. Predation appears to have had no significant impact. Future work should focus on contemporary investigations of the importance of hedgerow structure and woodland understorey vegetation.

REFERENCES

1.

S. R. Baillie , H. Q. P. Crick , D. E. Balmer , R. I. Bashford , L. P. Beaven , S. N. Freeman , J. H. Marchant , D. G. Noble , M. J. Raven , G. M. Siriwardena , R. Thewlis , C. V. Wernham 2001. Breeding Birds in the Wider Countryside: their conservation status 2000. BTO Res. Rep. no. 252. Thetford, Norfolk. ( http://www.bto.org/birdtrends). Google Scholar

2.

S. R. Baillie , R. D. Gregory , G. M. Siriwardena 1997. Farmland bird declines, patterns, processes and prospects. In: R. C. Kirkwood (ed.). Biodiversity and Conservation in Agriculture: BCPC Proc. No. 69: 65–87. British Crop Protection Council, Farnham. Google Scholar

3.

D. E. Chamberlain , R. J. Fuller , M. Shrubb , R. G. H. Bunce , J. C. Duckworth , D. G. Garthwaite , A. J. Impey , A. D. M. Hart 1999. The effects of agricultural change on birds. BTO Res. Rep. no. 209, Thetford, Norfolk, UK. Google Scholar

4.

M. J. Crawley 1993. GLIM for Ecologists. Blackwell Scientific, Oxford. Google Scholar

5.

H. Q. P. Crick 1992. A bird-habitat coding system for use in Britain and Ireland incorporating aspects of land management and human activity. Bird Study 39: 1–12. Google Scholar

6.

H. Q. P. Crick , S. R. Baillie 1996. A review of the BTO's Nest Record Scheme. Its value to the Joint Nature Conservation Committee and Country Agencies, and its methodology. BTO Res. Rep. no. 156. Thetford, Norfolk, UK. Google Scholar

7.

H. Q. P. Crick , C. Dudley , D. E. Glue , D. L. Thomson 1997. UK birds are laying eggs earlier. Nature 388: 526. Google Scholar

8.

H. Q. P. Crick , T. H. Sparks 1999. Climate change related to egglaying trends. Nature 399: 423– 424. Google Scholar

9.

D. W. Gibbons , W. J. B. Reid , R. A. Chapman 1993. The new atlas of breeding birds in Britain and Ireland: 1988–1991. T & AD Poyser, London. Google Scholar

10.

J. J. D. Greenwood, S. R. Baillie, H. Q. P. Crick, J. H. Marchant, W. J. Peach 1993. Integrated population monitoring: detecting the effects of diverse changes. In: R. W. Furness, J. J. D. Greenwood (eds). Birds as monitors of environmental change. Chapman, Hall, London, pp. 267–342. Google Scholar

11.

R. D. Gregory , S. R. Baillie 1998. Large-scale habitat use of declining British birds: implications for conservation. J. Appl. Ecol. 35: 785–799. Google Scholar

12.

R. D. Gregory , J. H. Marchant 1996. Population trends of jays, magpies and carrion crows in the United Kingdom. Bird Study 43: 28–37. Google Scholar

13.

C. Harrison 1975. A field guide to the nest, eggs and nestlings of European birds. Collins, London. Google Scholar

14.

J. R. Krebs, J. D. Wilson, R. B. Bradbury, G. M. Siriwardena 1999. The second silent spring? Nature 400: 611–612. Google Scholar

15.

J. H. Marchant , R. Hudson , S. P. Carter , P. Whittington 1990. Population trends in British breeding birds. British Trust for Ornithology, Thetford, Norfolk, UK. Google Scholar

16.

P. McCullagh , J. A. Neider 1989. Generalized linear models. 2nd edition. Chapman & Hall, London. Google Scholar

17.

J. A. Nelder , R. Mead 1965. A simplex method for function minimisation. Computer J. 7: 308– 313. Google Scholar

18.

I. Newton 1972. Finches. Collins, London. Google Scholar

19.

I. Newton 1999. An alternative approach to the measurement of seasonal trends in bird breeding success: a case study of the bullfinch Pyrrhula pyrrhula. J. Anim. Ecol. 68: 698–707. Google Scholar

20.

W. H. Press , B. P. Flannery , S. A. Teukolsky , W. T. Vetterling 1989. Numerical recipes: the art of scientific computing (FORTRAN version). Cambridge University Press, Cambridge. Google Scholar

21.

H. R. Pulliam 1988. Sources, sinks and population regulation. Am. Nat. 132: 652–661. Google Scholar

22.

SAS Institute, Inc. 1996. SAS/STAT software: changes and enhancements through release 6.11. SAS Institute, Inc., Cary, NC. Google Scholar

23.

J. T. R. Sharrock 1976. The atlas of breeding birds in Britain and Ireland. T & AD Poyser, Calton, Staffordshire. Google Scholar

24.

G. M. Siriwardena , S. R. Baillie , S. T. Buckland , R. M. Fewster , J. H. Marchant , J. D. Wilson 1998a. Trends in the abundance of farmland birds: a quantitative comparison of smoothed Common Birds Census indices. J. Appl. Ecol. 35: 24–43. Google Scholar

25.

G. M. Siriwardena , S. R. Baillie , H. Q. P. Crick , J. D. Wilson 2000a. Agricultural land-use and the spatial distribution of granivorous lowland farmland birds. Ecography 23: 702–719. Google Scholar

26.

G. M. Siriwardena , S. R. Baillie , H. Q. P. Crick , J. D. Wilson 2000b. The importance of variation in the breeding performance of seed-eating birds for their population trends on farmland. J. Appl. Ecol. 37: 122–138. Google Scholar

27.

G. M. Siriwardena , S. R. Baillie , H. Q. P. Crick , J. D. Wilson 2001. Changes in agricultural land-use and the breeding performance of granivorous farmland passerines. Agric. Ecosyst. Env. 84: 191–206. Google Scholar

28.

G. M. Siriwardena , S. R. Baillie , J. D. Wilson 1998b. Variation in the survival rates of some British passerines with respect to their population trends on farmland. Bird Study 45: 276–292. Google Scholar

29.

G. M. Siriwardena , S. R. Baillie , J. D. Wilson 1999. Temporal variation in the annual survival rates of six granivorous birds with contrasting population trends. Ibis 141: 621–636. Google Scholar

30.

G. M. Siriwardena , H. Q. P. Crick , S. R. Baillie , J. D. Wilson 2000c. Agricultural habitat-type and the breeding performance of granivorous farmland birds. Bird Study 47: 66–81. Google Scholar

31.

D. L. Thomson , R. E. Green , R. D. Gregory , S. R. Baillie 1998. The widespread declines of songbirds in rural Britain do not correlate with the spread of the avian predators. Proc. Roy. Soc. London B 265: 2057–2062. Google Scholar

32.

UK Biodiversity Group 1998. Tranche 2 action plans: volume 1 — vertebrates and vascular plants. English Nature, Peterborough. Google Scholar

33.

G. M. Tucker, M. F. Heath 1994. Birds in Europe: their Conservation Status. BirdLife International, Cambridge (BirdLife International Series No. 3). Google Scholar

34.

D. Vanhinsbergh , R. J. Fuller , D. G. Noble 2001. An analysis of changes in populations of British woodland birds 1966–1998 and a review of the possible causes. BTO Res. Rep. no. 245, Thetford, Norfolk, UK. Google Scholar

35.

C. V. Wernham, M. P. Toms, J. H. Marchant, J. A. Clark, G. M. Siriwardena, S. R. Baillie , in press. The migration atlas: movements of the birds of Britain and Ireland. T & AD Poyser, London. Google Scholar
Gavin M. Siriwardena, Stephen N. Freeman, and Humphrey Q. P. Crick "The Decline of the Bullfinch Pyrrhula pyrrhula in Britain: is the Mechanism Known?," Acta Ornithologica 36(2), 143-152, (1 December 2001). https://doi.org/10.3161/068.036.0207
Received: 1 March 2001; Accepted: 1 June 2001; Published: 1 December 2001
KEYWORDS
bird conservation
Bullfinch
demography
granivorous birds
population models
Pyrrhula pyrrhula
Back to Top