Spiders thrive thanks to snakes.
The accidental introduction of the brown tree snake to the Pacific island of Guam has resulted in a dramatic increase in the island's spider population, according to a new study published in PLoS ONE.
Following the introduction, which took place during the 1940s, Guam's bird population was almost completely wiped out; of 12 species of native bird, only two remained by the 1980s. 'There isn't any other place in the world that has lost all of its insect-eating birds,' said the study's lead author, Haldre Rogers, of Rice University in Texas. 'There's no other place you can look to see what happens when birds are removed over an entire landscape.'
The most obvious impact has been on the spider population. 'You can't walk through the jungles on Guam without a stick in your hand to knock down the spider webs,' said Rogers.
Over a four-month period, Rogers and his team counted spider's webs on Guam and on neighbouring islands. They found that in some areas on Guam, spiders were 40 times more abundant than they were on neighbouring islands.
'Ultimately, we aim to untangle the impact of bird loss on the entire food web, all the way down to plants,' said Rogers. 'For example, has the loss of birds also led to an increase in the number of plant eating insects? Or can this increase in spiders compensate for the loss of birds?'
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|Article Type:||Brief article|
|Date:||Nov 1, 2012|
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