Biodiversity & Conservation

, Volume 6, Issue 4, pp 615–625 | Cite as

How many birds are there?

  • Kevin J. Gaston
  • Tim M. Blackburn


Attempts to assess the magnitude of global biodiversity have focused on estimating species richness. However, this is but one component of biodiversity, and others, such as numbers of individuals or biomass, are at least as poorly known and just as important to quantify. Here, we use a variety of methods to estimate the global number of individuals for a single taxon, birds. The different methods yield surprisingly consistent estimates of a global bird population of between 200 billion and 400 billion individuals (1 billion=109). We discuss some of the implications of this figure.

biodiversity birds populations 


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Copyright information

© Chapman and Hall 1997

Authors and Affiliations

  • Kevin J. Gaston
    • 1
  • Tim M. Blackburn
    • 2
  1. 1.Department of Animal and Plant SciencesUniversity of SheffieldSheffieldUK
  2. 2.NERC Centre for Population BiologyImperial CollegeAscot, BerkshireUK

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