Hagfish defend themselves by oozing up to a gallon of mucous from their slime pores.
The Amazon - life on the edge
The Amazon - life on the edge A fragment of rainforest in the centre of the
Brazilian Amazon comprises one of the world’s most famous
experiments in ecology, and it is us teaching some unexpected
lessons.
Two decades ago, Thomas Lovejoy set out to learn what would happen
to fragments of forest ecosystems left behind after men and
chainsaws had done their worst. Forest tracts of 1, 10 or 100
hectares square were left. Conservationists needed to know if they
had to protect some critical minimum size of forest tract in order
to preserve a real functioning rainforest ecosystem. Now, 20 years
later, some answers are starting to emerge. Some species were
squeezed out of the smaller fragments of land. Large, mixed-species
flocks of insect-eating birds dispersed within 2 years of isolation
in the 1 and 10 hectare fragments, leaving only a few stragglers.
Many other single species flocks of insectivorous birds also
vanished from the fragments over the first 3 to 6 years. To the
surprise of the researchers, though, the future of most individuals
depended more on how close they were to the edge of the forest and
on what sort of habitat surrounded the forest fragment.
The effects of forest fragmentation have turned out to be more
complex than expected. But new information offers better tools for
conservationists who want to preserve as many rainforest species as
possible. 21 SEPTEMBER 1996, P. 38-39
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