hello tweeters,

yet more on the moas record-breaking extinction at the hands of
humans.

regards,

Deborah Wisti-Peterson email:nyneve at u.washington.edu
Department of Zoology, University of Washington, Seattle, Wash, USA
Visit me on the web: http://students.washington.edu/~nyneve/
<><><>Graduate School: it's not just a job, it's an indenture!<><><>


---------- Forwarded message ----------

>
> By Mari N. Jensen,
> Discovery.com News
>
> March 24, 2000 -- The first humans to arrive in New Zealand drove
> large, flightless birds called moas to extinction in less than 100
> years -- faster than any other documented extinction.
>
> Paleobiologist Richard Holdaway of Palaecol Research in Christchurch,
> New Zealand, reporting in today's journal Science, used a computer
> simulation to figure out how the moa population would respond to
> hunting pressure from a 100-person band of settlers.
>
> By using information known about other large birds living in forests,
> he estimated that about 160,000 moas were alive when Polynesians
> reached New Zealand in the late 13th century. Scientists know about
> moas only from fossils and archaeological digs.
>
> Even using the most conservative estimates of moa consumption and
> human population growth, he found that all the big birds vanished
> about 160 years after people arrived.
>
> Punching more realistic estimates into his computer, he found that all
> 11 species of moas -- from the turkey-sized ones to those bigger than
> ostriches -- were gone within a century of people reaching the
> islands.
>
> Moas, thought to live 30 or 40 years and to reproduce slowly, just
> couldn't handle the additional predation from humans, Holdaway says.
> "Long-lived animals cannot tolerate high adult mortality -- or even,
> as it turns out, slightly higher adult mortality."
>
> To verify when moas became unavailable for food, co-author Chris
> Jacomb, an archaeologist at Christchurch's Canterbury Museum, dated
> bits of sea shells from excavated garbage pits and found that people
> switched from munching moa to grubbing for clams around the late 14th
> century.
>
> That's a better way to figure out when moas went extinct than dating
> moa bones and hoping they were bones from the last moa ever, Holdaway
> says. "I don't believe people would eat shellfish if they could have
> turkey."
>
> Jared Diamond, a University of California, Los Angeles physiologist,
> writes in a companion article in Science that the event -- in which
> only simple tools like snares and clubs were used -- was a blitzkrieg.
>
> "Yes, a few people could and did kill every moa," adding, "Then, there
> were no more moas; soon, there will be no more Chilean sea bass,
> Atlantic swordfish or tuna."
>
> David Steadman, an avian paleontologist at the University of Florida
> in Gainesville, isn't convinced.
>
> "I think the model is utter speculation," he says. "Until there's a
> bunch of direct radiocarbon dates on moa bones, the chronology of
> their extinction is up in the air."
>
> 1. http://www.discovery.com/