At risk bird, Hutton's Shearwater, has lost an estimated quarter of their population
A landslip caused by the 7.5 earthquake has wiped away half of a breeding colony for the at-risk Hutton's Shearwater bird.
The Hutton's Shearwater is an endemic bird that only breeds on New Zealand land, and as a result of human contact, predators and lost habitat, its numbers are declining.
"The total population was only 110,000 -- quite small really, for a shearwater," said seabird expert Karen Baird.
Baird predicts that at least 25 percent of the population will have been wiped out by the earthquake -- though the number could be as high as 49 percent, according to an Important Bird Areas report.
"It's horrible, it's our worst nightmare," Baird said.
"Both of our main colonies are up in the mountain in Kaikoura. They're only in Kaikoura."
While one colony is safe, half of one has been swept away, according to the Department of Conservation (DoC).
However, a fledgling colony recently set up on the Kaikoura peninsula should be safe.
"It's not a steep site, and it's covered in grass."
Shearwaters are not known for their resilience -- adults are long-lived and slow-breeding, laying only one egg a year at most.
This means they cannot replace their population quickly.
That the slip occurred during breeding season is an especially cruel blow, Baird said.
"It's going to be devastating for the population. We lost adults, who we need to keep the population. It's horrendous."
Hutton's Shearwater are only one at-risk bird in the Kaikoura area who could be affected by the quakes.
Others include spotted shags, kea and redbill gulls.
DoC are currently attempting to gauge how many birds have been lost.
Baird would like to see more resources given to DoC to redress the damage caused by the quake.
"It's a devastating loss for an already at risk species... that is so important to so many people."