0198566123.pdf

(Marcin) #1

and Olson 1991). Pimm et al. (1995) believe that
roughly 125–145 bird species once inhabited the
main islands, of which 90–110 are extinct, with
another 10 considered imminently threatened with
extinction. The original avifauna contained only
three non-endemic land birds, and all the passer-
ines were endemic, yet in consequence of the enor-
mous losses and of large numbers of species
introductions by humans, only about a third of the
passerines found on Hawaii today are endemic.
Nearly all the birds seen now below 1000 mASLare
aliens. Today, some 48% of the land birds of Hawaii
are exotics introduced and released in order to
augment the fauna with game birds and birds of


beautiful plumage or song. Of 94 species known to
have been introduced before 1940, 53 species
became established at least locally and only 41
failed completely.
The Hawaiian islands illustrate another feature
of prehistoric extinctions, namely, how they altered
the structure of vertebrate—specifically bird—feed-
ing guilds. All but one species of native predator
became extinct (James 1995). Such was the fate of
the terrestrial herbivores, with the exception only of
the Hawaiian goose (Branta sandvicensis), which
was rescued from the brink of extinction only by an
ex situbreeding programme. Losses included the
large flightless anseriforms (moa-nalos), which

308 ANTHROPOGENIC LOSSES AND THREATS TO ISLAND ECOSYSTEMS


NEW
ZEALAND
CHATHA

M IS.

KERMADEC IS.

TongatapuRanotongaMaria
S. COOKS IS.
Vava’u
TubuaiRaivavae
Rapa

Pitcairn Easter

Henderson
Mangareva

TUAMOTU IS.

MARQUESAS IS.

El’ao
FlintCaroline

Malden
Sydney Starbuck
VostokTongareva
N.COOKS IS.Suwarrow

SAMOA IS.TOKELAU IS.

PalmerstonSOCIETY IS.

TONGA IS.

FIJI IS.

TUVALU

HowlandWashingtonLINE IS.
Jarvis

Fanning
Christmas

Palmyra

POLYNESIA

Johnston

PHOENIX IS
Baker

MARSHALL

IS.

MICRONESIA
CAROLINE IS.
KIRIBATI
Nukuoro
NukumanuOntong Java
Sikaiana
SANTA RotumaCRUZ
VANUATURennell IS.FutunaUvea

MELANE

SIA
NEW CALEDONIA

Lord Howe

Norfolk

New Guinea
SOLOMON
IS.

HAWAILAN IS.

Midway
Necker
Nihoa

REVILLA GIGEDO IS.

Cocos
Malpelo

GALAPAGOS IS.

San Felix
San Ambrosio

JUAN FERNANDEZ IS.

140 ̊ 160 ̊ 180 ̊ 160 ̊ 140 ̊ 120 ̊ 100 ̊ 80 ̊

40 ̊


20 ̊

0 ̊

20 ̊

40 ̊

140 ̊ 160 ̊ 180 ̊ 160 ̊ 140 ̊ 120 ̊ 100 ̊ 80 ̊

40 ̊

20 ̊

0 ̊

20 ̊

40 ̊

Oeno

Figure 11.4Map of the Pacific showing Polynesia. At the time of European contact, many islands in the eastern and central Pacific were
uninhabited (large dots). Crosses mark islands colonized by the Polynesians prior to AD1500 but then abandoned, usually after the extinction of
many native species. Question marks indicate those islands where pre-European colonization was noted by Brown and Lomolino (1998) as
suspected but not clearly documented. (Source: Brown and Lomolino 1998, after Terrell 1986.)

Free download pdf