"I hope that George doesn't keep you up. He's at his most vocal at 3 a.m., as you may have noticed," Prince William told his hosts Thursday at a state dinner at the governor general's residence, where he and wife Kate have been staying with their 8-month-old son.
"I swear I heard him doing the haka this morning," William joked to the 200 guests, referring to the aggressive war dance made famous by the country's All Blacks rugby team before games.
Perhaps that's fitting, William added. "He's a bonny lad, and you'll be pleased to know that he's currently preparing for life as a [rugby player]."
The governor general, Sir Jerry Mateparae, welcomed the couple in a warm speech before dinner but admitted that "the prestige goes to Prince George … There has been a hubbub of delight from New Zealanders."
The feeling was mutual. "I cannot tell you how happy I am to be back here in God's Own Country, as I have learned to call it, and this time with my wife and son," William said.
Praising the country for its "warmheartedness, generosity, neighborliness, openness, an instinctive sense of justice and freedom," William unveiled a new portrait of his grandmother, Queen Elizabeth, by the young New Zealand artist Nick Cuthel.
Kate, 31, who has been working local fashions into her wardrobe since her arrival, wore a bespoke black Jenny Packham dress which had been hand-stitched with silver beading in a pattern representing New Zealand's national emblem.
Mark Mitchell / Getty
A Day in BlenheimEarlier in the day, the Duke and Duchess visited Blenheim on New Zealand's South Island, where they accepted cuddly toys and clothes for George, who stayed behind in Wellington.
"We asked her about Prince George, and she said she would have taken him everywhere but he would have been a bit noisy," a local girl named Lilah told PEOPLE.
The couple were in town to lay a wreath as part of New Zealand's build-up to Anzac Day of military remembrance later this month, but spent half an hour shaking hands and chatting with people who had waited hours to see them.
They also visited an aircraft museum, where William, a former Royal Air Force pilot, climbed into a vintage airplane – with Lord of the Rings filmmaker Peter Jackson filming the whole thing on his iPhone.
"Perfect. Fine by me. Start her up," William joked as he surveyed the ancient controls. "Now, how to get out of this without getting smacked on the head?"
Jackson gave the royals a tour of the museum, where he has collected World War I uniforms and memorabilia and 30 vintage aircraft, presented amid stunning re-enactments of battle scenes designed by film-set artists.
Jackson gave William and Kate a personal memento of their visit: a replica of a World War I pilot's hip flask. And for George? A replica of a vintage flying helmet. "We'll give this to him when he's older," William said.