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Dodos weren’t alone: Huge bird die-off blamed on ancient man

March 25, 2013
Courtesy of the Zoological Society of London
and World Science staff

The last re­gion on Earth col­o­nized by peo­ple har­bored more than 1,000 spe­cies of birds that died out shortly there­af­ter, ac­cord­ing to new re­search.

A re­port on the find­ings ap­pears in this week’s early on­line edi­tion of the jour­nal Pro­ceed­ings of the Na­t­ional Acad­e­my of Sci­ences.

The Ta­ka­he, an flight­less bird from New Zea­land that still lives but is en­dan­gered. (Im­age cour­te­sy of Tim Black­burn)


Al­most 4,000 years ago, trop­i­cal Pa­cif­ic Is­lands were an un­touched par­a­dise, ac­cord­ing to a team of Zo­o­log­i­cal So­ci­e­ty of Lon­don re­search­ers and col­la­bo­ra­tors who car­ried out the work. But the ar­ri­val of peo­ple in places like Ha­waii and Fi­ji caused ir­re­vers­i­ble dam­age due to over­hunt­ing and de­for­esta­t­ion. As a re­sult, birds dis­ap­peared. But un­der­stand­ing the scale and ex­tent of these ex­tinc­tions has been ham­pered by un­cer­tain­ties in the fos­sil rec­ord.

“We stud­ied fos­sils from 41 trop­i­cal Pa­cif­ic is­lands and us­ing new tech­niques we were able to gauge how many ex­tra spe­cies of bird dis­ap­peared with­out leav­ing any trace,” said Tim Black­burn, di­rec­tor of the so­ci­ety’s In­sti­tute of Zo­ol­o­gy.

The team found that 160 spe­cies of non-passerine (non-perching) land birds died out with­out a trace af­ter the first hu­mans ar­rived on these is­lands alone. “If we take in­to ac­count all the oth­er is­lands in the trop­i­cal Pa­cif­ic, as well as seabirds and song­birds, the to­tal ex­tinction toll is likely to have been around 1,300 bird spe­cies,” Black­burn added.

Spe­cies lost in­clude sev­er­al spe­cies of moa-nalos, large flight­less wa­ter­fowl from Ha­waii, and the New Cal­e­do­ni­an Sylv­ior­nis, a rel­a­tive of the game birds (pheas­ants, grouse, etc) but which weighed in at around 30 kg (70 pounds), three times as heavy as a swan.

Cer­tain is­lands and spe­cies were par­tic­u­larly vulnera­ble, the re­search­ers said. Small, dry is­lands lost more spe­cies be­cause for­est cov­er and hid­ing places were spars­er. And flight­less birds were over 30 times more likely to be­come ex­tinct than fliers.

Bird ex­tinc­tions in the trop­i­cal Pa­cif­ic did not stop with these losses, the team added. For­ty more spe­cies dis­ap­peared af­ter Eu­ro­peans ar­rived, and many more spe­cies are still threat­ened.

The die-offs had some­thing in com­mon with one of the most fa­mous ex­tinc­tions of his­to­ry, that of the do­do, al­though that oc­curred at anoth­er place and time. Found by Dutch sol­diers around 1600 on an is­land in the In­di­an Ocean, the do­do, a flight­less bird, per­ished with­in 80 years be­cause of de­for­esta­t­ion, hunt­ing, and de­struc­tion of their nests by an­i­mals in­tro­duced by the Dutch.


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The last region on Earth colonised by people harbored more than 1,000 species of birds that died out shortly thereafter, according to new research. A report on the findings appears in this week’s early online edition of the journal Proceedings of the National Academy of Sciences USA. Almost 4,000 years ago, tropical Pacific Islands were an untouched paradise, according to a team of Zoological Society of London researchers and collaborators, who carried out the work. But the arrival of people in places like Hawaii and Fiji caused irreversible damage due to overhunting and deforestation. As a result, birds disappeared. But understanding the scale and extent of these extinctions has been hampered by uncertainties in the fossil record. “We studied fossils from 41 tropical Pacific islands and using new techniques we were able to gauge how many extra species of bird disappeared without leaving any trace,” said Tim Blackburn, director of the society’s Institute of Zoology. The team found that 160 species of non-passerine (non-perching) land birds went extinct without a trace after the first humans arrived on these islands alone. “If we take into account all the other islands in the tropical Pacific, as well as seabirds and songbirds, the total extinction toll is likely to have been around 1,300 bird species,” Blackburn added. Species lost include several species of moa-nalos, large flightless waterfowl from Hawaii, and the New Caledonian Sylviornis, a relative of the game birds (pheasants, grouse, etc) but which weighed in at around 30kg, three times as heavy as a swan. Certain islands and bird species were particularly vulnerable to hunting and habitat destruction, the researchers said. Small, dry islands lost more species because forest cover and hiding places were sparser. And flightless birds were over 30 times more likely to become extinct than fliers. Bird extinctions in the tropical Pacific did not stop with these losses, the team added. Forty more species disappeared after Europeans arrived, and many more species are still threatened with extinction today. The die-offs had something in common with one of the most famous extinctions of history, that of the dodo, although that occurred at another place and time. Found by Dutch soldiers around 1600 on an island in the Indian Ocean, the dodo, a flightless bird, perished within 80 years because of deforestation, hunting, and destruction of their nests by animals introduced by the Dutch.