Where Australia Collides with AsiaJohn Gould was particularly excited by the rather nondescript little birds from
the Galapagos. Darwin had assumed they were from several different groups: wrens,
finches, blackbirds, etc. However, Gould believed that despite their totally different
beaks they were all finches. The problem was that Darwin’s collecting on Galapagos
had been uncharacteristically clumsy. He had failed to completely label from which
island his birds had been collected, never imagining that different islands, not far
apart, would produce different birds. Gould needed to examine more Galapagos birds
that were correctly labelled and Darwin had to go to Robert FitzRoy and his own
assistant Syms Covington to borrow their specimens.
John Gould now classified all the birds as finches and observed how their beaks
had adapted to eat insects, cactus or seeds. In the absence of other bird species, the
finches had adapted to different food niches. On one island the beaks were stronger to
crack nuts and seeds, on another island the beaks were smaller to catch insects, and
on other island the beak was especially useful for feeding on fruits and flowers. With
these new specimens Gould’s initial conclusion was confirmed: here was a group
of birds that were closely related yet their beaks had adapted according to the food
they ate – different islands, different finches, different species. Thomas Bell from the
Royal Zoological Society, who had been identifying Darwin’s reptile collection, came
up with a similar conclusion, as each of the Galapagos Islands had produced its own
distinct species of iguana lizard.
Four species of Galapagos finch with different beaks, from Darwin’s Journal of
Researches94
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