The researchers said the global economic crisis would only slow down migration rates temporarily.

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This allows travellers a chance to get a sneak peek of the migration down south before indulging in the crowd-free wildlife show of the north.

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Estimates taken in 2000 had over-estimated Scotland's population by about 50, 000 or 1% and this could have been down to the difficult task of measuring migration of people.

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It said the boom was down to women having babies later and increased migration to NI.

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The group follows the migration of mackerel from the Norwegian sea, past Shetland and down the west coast of Ireland and Britain possibly as far as the Portuguese coast.

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Sir Andrew Green, chairman of the campaign group Migration Watch UK, said it had to be the "right approach" to try to get immigration down by being "much more selective".

BBC: Immigrants 'must add to quality of life in Britain'