School principals say they are "pleasantly surprised" by a turnout of just under 80 per cent of students on the first full school day after the Covid-19 lockdown.
Ministry of Education data received from 1470 of the country's 2517 schools shows an average attendance rate of 79 per cent.
A smaller Facebook survey of 400 schools by the NZ Principals' Federation reported 82 per cent attendance.
Federation president Perry Rush said he was "pleasantly surprised" by the figures.
"I think to have a 1 to 2 per cent return rate at level 3 and 80 per cent or so at level 2, given that this is the first day, is pretty good," he said.
"We know that there will be families who are not sending their children, it might be for a few days, but this is a good first indicator that confidence is there."
Attendance in his survey ranged from highs of almost 100 per cent down to just 28 per cent at Ōtangarei School in Whangārei, where principal Myles Ferris said many families had been scared by a rumour circulating on social media.
"Apparently there's a message going around that Oranga Tamariki and police are going to come in and take children away without the parents' knowledge and have them medicated, all without informing the parents," he said.
He posted a message on his school's Facebook page saying he would never let a child be taken by Oranga Tamariki or be medicated without talking to the parents first.
Leanne Otene, principal of another Whangārei school, Manaia View, said 50 per cent of her students turned up, but that was partly because about 25 per cent had asthma and other conditions that made them vulnerable to any Covid-19 outbreak.
Te Tai Tokerau Principals' Association president Pat Newman said 70 per cent of his students at Hora Hora School turned up, but he had also been asked on Facebook about the Oranga Tamariki rumour.
"I nearly fell off my seat in laughter," he said.
"It's just that usual feeling of the unknown. It's an unusual Te Tai Tokerau belief."
Northland also had the lowest regional attendance during alert level 3, with only 1 per cent of its school rolls turning up on any day between April 29 and May 15 - about half the national average of 2 per cent.
Both school and early childhood attendance rates during level 3 were highest in Auckland, Waikato and South Island regions.
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Parents were as excited as their children as they arrived at one Auckland school, decile 5 Flanshaw Road School in Te Atatū, even though it is close to one of the deadliest Covid-19 clusters at St Margaret's rest home.
Principal Cherie Taylor-Patel reported a turnout of 73 per cent.
Parents Marcel and Rebecca Fletcher said their two children aged 7 and 5 had loved being at home with their parents, but both parents were working at home so schoolwork had "kind of been on the backburner to be honest".
Their son Ante, 7, said he was "a little bit scared about going back to school".
But both Emily Knight, 8, and her mother Fiona Knight said they were "excited" to be back.
"I get to see my friends again," Emily said.
Fiona said the family had spent time together playing games and "doing stuff together" in the lockdown.
"We have not had that time together as a family," she said.
"But I work for an organisation that is quite aware of the risks, so I'm not bothered [with school resuming]."
Red Beach School on the Whangaparāoa Peninsula, where teachers dressed in wigs and decked the school in balloons to welcome children back, reported 95 per cent attendance and "lots of happy faces".
"Lots of kids were coming through the gate with projects and things that they made in the lockdown," said principal Julie Hepburn.
In South Auckland, Ormiston Primary School also reported a low turnout of 62 per cent. Principal Heath McNeil said many parents came from countries where the pandemic is still raging and much tighter controls are still in place.
Auckland Secondary Schools Principals' Association president Steve Hargreaves said his attendance rate at Macleans College was 96.3 per cent.
Rangitoto College reported 98 per cent, St Peter's College 96 per cent, and several other secondary schools were in the mid-90s.
Hargreaves said fears of hundreds being left on the roadside because of reduced capacity on buses did not materialise.
"We picked up a couple, and I just had an angry email from one dad whose son missed out," he said.
"But we had huge numbers of parents driving their kids to school. There was a bit of a traffic jam outside this morning."
Auckland Transport spokesman Mark Hannan said AT had no reports of children being left behind, even though bus capacity has been reduced to 43 per cent of normal because of rules requiring only one passenger in each pair of seats, no one sitting close to the driver and no one standing in the aisle.
"We estimate buses, trains and ferries in Auckland were about a third full," he said.
"We had one route in West Auckland with capacity issues but people were picked up by a following bus."
However a Remuera parent said her Year 10 daughter at Baradene College was told that there were only enough seats on the bus home after school for students in Years 7 to 9.
"So she just kept walking until she found another bus that took her," the parent said. "These were not school buses, as her school buses didn't run today."
Hannan said: "In the current situation we cannot guarantee that passengers can get on the first bus. Our AT Mobile app will point them to the next bus with capacity."
• Level 2 rules: covid19.govt.nz.