The Royal Society for the Protection of Birds, The Lodge, Sanely, Bedfordshire U.K. SG19 2DL.
Abundance patterns of European breeding birds
Version of Record online: 28 JUN 2008
Volume 23, Issue 2, pages 201–208, April 2000
How to Cite
Gregory, R. D. (2000), Abundance patterns of European breeding birds. Ecography, 23: 201–208. doi: 10.1111/j.1600-0587.2000.tb00276.x
- Issue online: 28 JUN 2008
- Version of Record online: 28 JUN 2008
- Accepted 23 August 1999
The frequency distribution of national population sizes of breeding birds was examined for each of 48 European countries, including autonomous regions, using data from the European Bird Database. The frequency distribution of logarithmically transformed abundance was left skewed in 40 countries: there was significant left skew in 10, and positive skew, in 2 countries. The inclusion of data classed as of low quality did not alter the conclusion that abundance patterns were predominantly left skewed. Abundance patterns of resident and migrant breeding birds differed; residents were left skewed, migrants were lognormal. Skewness was correlated negatively the number of species within a country. At low sample size, both left and right skews were evident, but left skews predominated at larger samples sizes. This pattern was driven partly by a difference between breeding populations on islands and on continental countries. Resampling procedures with fixed sample size showed that resident and migrant birds differed consistently in their patterns of skew, independent of sample size. If the birds of Europe were treated as a single assemblage, their abundance pattern was left skewed but this was driven by a very small number of vagrant breeders.