Daksh's mother was born in Tonga and moved to New Zealand 14 years ago, and his father is an Indian native.
Ms Tupou said her son was blessed to be born here. "It's a blessing for babies to be born here, in opportunity, it's a good country. We are very happy to be in this country."
According to the Census data, baby Daksh will also fall into one of the five largest ethnic groups, identified as New Zealand European, Maori, Chinese, Samoan and Indian.
Ethnic diversity has been increasing since 2006, especially within the broader Asian category spearheaded by Chinese, Indian, and Filipino ethnicities.
During the seven years between censuses, the Chinese population increased by 16 per cent to 171,000, the number of Indians increased by 48 per cent to 155,000 and Filipinos more than doubled to 40,000. New Zealand, and Auckland in particular, were now classified as "super diverse", said Massey University humanities and social sciences research director Professor Paul Spoonley.
"That has two aspects. One is the size of the non-majority populations - the fact that 23 per cent of Auckland is Asian - they're a very significant non-majority population. The other aspect is the number of immigrant and ethnic communities."
Statistics New Zealand population estimates and projections manager Jo-Anne Skinner said the 4.5 million milestone differed from data that showed just 4.24 million Kiwis on Census night in March.
Census data doesn't include New Zealanders overseas on the night or people who did not fill out their form.
The estimated population was adjusted for births, deaths and net migration since Census night.
"From that time there have been regular population increases and we have had nine months since that time," she said.
The country's population increases by one person every 7 minutes 42 seconds based on a birth every eight minutes, a death every 17 minutes 53 seconds and a new migrant every 14 minutes 20 seconds.
We are on track to reach the next population milestone - 5 million - in 2026.
