HUNDREDS of dead migratory birds have been found washed up on Tweed beaches this week, with the storm season and natural selection both at play.
Lawrence Orel from the National Parks and Wildlife Service said while it would be distressing for residents, not much can be done to help the birds.
Mr Orel said medical care would do little good for any of the birds found alive on the beaches.
"It can be heartbreaking and distressing, but wildlife carers are being overwhelmed by numbers of these birds," Mr Orel said.
"Unfortunately, there's not much that can be done."
"Even under the care of the most experienced wildlife carers, these birds tend not to survive."
Mr Orel said despite much effort to help the birds, a Coffs Harbour vet has studied some specimens, only to conclude they were in a state of exhaustion and starvation beyond rehabilitation.
"They had used all their energy and they had no fat layer," Mr Orel said.
"It's a natural phenomena resulting from one of the longest journey of any animal."
Mr Orel said the birds are generally so low in energy reserves, bringing them to carers would only choke up much-needed facilities.
Mr Orel said the short-tailed shearwaters - commonly known as the mutton birds -would have been on the last leg of their migratory journey before succumbing to starvation and exhaustion.
"They are returning from their annual migration," Mr Orel said.
"They breed around Bass Strait and Tasmania before leaving in April to feed.
Mr Orel said while there would always be a natural level of fatalities involved in this journey, violent storms would be a contributing factor to excessive numbers of birds washing up on Tweed beaches.
"Storms and strong winds force their energy consumption up," Mr Orel said.
He said while this seems to be an unfortunate occurrence, this brutal natural selection helps to maintain the strength of the overall population.
The mutton bird is one of the world's most abundant bird species, with a population well over 18 million.
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