WASHINGTON : The Dodo, the famous flightless bird that inhabited the Indian Ocean island of Mauritius, is a case study in extinction caused by humans. The Dodo, finely adapted to its isolated ecosystem but unprepared for the arrival of people, was first encountered by Dutch sailors in 1598. Hunting, habitat destruction and the introduction of non-native species doomed it in under 80 years.
It is hardly alone. New research has documented the extinction of 610 bird species over the past 130,000 years, coinciding with the global spread of our species Homo sapiens, an avian crisis that has only accelerated in recent years and decades. For instance, the Kauaʻi ʻōʻō, a Hawaiian songbird, was declared extinct just last year.
The researchers also revealed the ecological consequences, as the disappearance of avian species erases functions they serve in innumerable ecosystems.
“Birds undertake a number of really important ecosystem functions, many of which we depend on, such as the dispersal of seeds, the consumption of insects, the recycling of dead material – for example, vultures – and pollination. If we lose species, then we lose these functions,” said ecologist Tom Matthews of the University of Birmingham in England, lead author of the study published this week in the journal Science.
“A good example of this is on the islands of Mauritius and Hawaii, where all or almost all the native frugivores – birds that eat fruit – have gone extinct,” Matthews said.
The Dodo and Kauaʻi ʻōʻō, believed to have had fruit as part of their diets, were among those.
“Frugivory is an important function, as in eating the fruits and then moving around, birds will disperse the seeds of the plants the fruits belong to,” Matthews said.
This can precipitate “secondary knock-on extinctions,” Matthews said, with Mauritius now having many threatened tree species.
Most of the documented extinctions occurred on
