The annual godwit migration has come early this year, with the birds arriving in Christchurch two weeks ahead of time.
A joke doing the rounds is that they have fled Alaska on learning that Sarah Palin has joined the US presidential race, but a more likely theory has to do with global warming.
The arrival of the first godwits of spring is a significant day on Christchurch's calendar. Their presence is announced with the sounding the bells of the Christchurch cathedral.
Every September the birds make the non-stop 11,000 kilometre journey from Alaska - the longest migration of any bird. And this year marks their earliest arrival yet.
"I've been monitoring their arrival for 25 years, and this is by far the earliest arrival," park ranger Andrew Crossland says. "Last year they were about a week later than this year, but normally they're about two to three weeks later than now."
500 godwits have touched down in Christchurch since Sunday. Mr Crossland suspects climate change could be to blame for their early arrival, but he is waiting for more information from Alaska.
The birds will breed here over the summer months before fattening up for their epic journey home in March.
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