The number of terns in the area has increased significantly since last season, said Lyttelton Port Company environment and sustainability adviser Charlotte Jones.
“It’s great to see them settling in here.”
Nesting season lasts from October to February and when the birds migrate, Jones said some are likely to travel as far as Australia.
“There were only a couple of nesting pairs last season,” she said.
“We’ll just keep an eye on the birds and expect to see even more next year.”
The terns are nesting in the disused wharf and rocky sea wall near the cruise berth.
Jones said pest monitoring conducted by the port company has likely encouraged the growth of the colony.
“There are reduced pests around the area which would increase the nesting success, as pests like possums, rats and mustelids will predate on chicks and eggs.”
At least 20 chicks had hatched by the end of December, she said.
“It’s a really safe spot for the birds.
The port is also host to the common red-billed gull, which have built a similar-sized colony to the terns, as well as a small number of oyster catchers.