Skip to content

How Many Bid Species are There in the World?

This is a harder question to answer than you might imagine. Until very recently it was believed that 95% of the world’s species had been identified and described. On this basis, it was felt that there were somewhere between 9,000 and 10,000 different species across the globe. But the latest research suggests that this figure is incorrect.

A study overseen by the American Museum of Natural History in 2016 has revealed that there may be as many as 20,000 distinct species of birds. The research has uncovered what has been described as a hidden diversity in avian species. The study was conducted because ornithologists believed that the criteria which have been used to identify species were erroneous. They felt that birds which looked similar or interbred may have been treated as one species when they actually possessed unique evolutionary histories.

For the American research, 200 birds were chosen and studied. On average, for each bird, 2 separate species were identified which would suggest that there are twice as many different species as previously thought. However, birds were chosen for the study, at least in part because diversity was suspected and so the new estimate could be an exaggeration. The situation is about as clear as mud!

UK Avian Species

There are 596 species which have been recorded as living wild in the UK and so the country boasts surprising diversity. But even this apparently straightforward statistic is riddled with complexity!

Some of the birds which are mentioned on the British List as existing in the wild in Britain may have been here only once since records began, whilst others live here in their millions. The list is collated and maintained by the British Ornithologists Union (BOU) and divides birds into 5
categories:

  • Category A – species which have been recorded in an apparently natural state at least once since 1 January 1950.
  • Category B – Birds which have recorded at least once in an apparently natural state between 1 January 1800 and 31 December 1949, but which have not been recorded since.
  • Category C – Species which have been introduced to the UK but where the current specimens are derived from the resulting self-sustaining populations. (These birds include mandarin ducks and ring-necked parakeets).
  • Category D – Species which you may happen to see and which would appear in category A except that there is reason to doubt that they have ever occurred in a natural state in the UK. This category would include bald eagles.
  • Category E – Species of birds which have been recorded as introductions, human-assisted transportees and birds which have escaped from captivity but which do not have self-sustaining populations. Examples here would include black swans and peacocks.

World Record Bird Spotter

Many bird watchers keep a record of how many species they have seen and some enthusiasts log these online. If you manage to spot every species which has been identified on the British List, you have achieved something truly special. We couldn’t find anyone who has claimed to have spotted every bird but we can tell you that in 2012, twitcher Tom Gillick became the first person in the world to officially spot 9,000 of the planet’s species!

Hello,

We are very sorry, but the browser you are visting us with is outdated and not complient with our website security.

Please upgrade your browser to a modern secure version to view our website.