Staff at highly regarded North Shore secondary school Westlake Boys High are accustomed to seeing the backs of their gangly, green-clad students when the 3.15pm bell tolls.

But it's a near certainty that most students - grumbling though they may be - will be back, backpacks slung over wiry shoulders, in the morning.

There is a new exodus from Westlake Boys High that is a little harder for seasoned staff members to acclimatise to: the flight of their young teaching colleagues from their jobs, tired and claiming to be underpaid. They are not likely to return through these, or any school's, gates any time soon.

If statistics from this year's school staffing report from the PPTA are accurate, more than half of all new secondary teachers who leave their jobs for whatever reason - be it overwork, underpay, or just plain incompatibility - leave the profession altogether.

Historically, between 9 and 10 per cent of all new teachers - those in their first, second or third year - leave teaching each year. But stalwart PPTA teachers believe that the rate of burnout and disillusion has intensified lately, spurred on by industrial unrest and the extra work of administering the new National Certificate of Achievement system.

The Ministry of Education has not collected the figures for this year's drop-out profile, it says. Last year's confirm that most of those who left entered occupations outside teaching. The next sizeable number were those who left to teach overseas. More than 1200 left the country's 15,000 permanent secondary teaching population, roughly 600 of those to work outside teaching, to teach overseas, to teach in the private sector, or for "personal" reasons. This year's figures are higher, says the PPTA.

Principals had more difficulty filling vacancies at the beginning of the school year than in previous years - even the ministry admits that - with shortages taking on worrying new characteristics. Around 20 per cent of the nation's 300-plus secondary schools had vacancies as term one began, slightly down from last year's 23 per cent but more likely to persist into the school year.

Whereas gaps have traditionally occurred in maths and science (13 per cent of all vacancies, says the ministry) and technology, shortages are also emerging in English (also 13 per cent) and "management" - accounting, economics and associated areas.

And low-decile schools and those in rural areas, which have always had some difficulty attracting staff, are increasingly joined by high-decile schools facing similar problems: new teachers being lost to other professions or overseas opportunities, experienced teachers, especially in science and maths, leaving and a lack of suitable New Zealand candidates (and in some cases, no candidates) for advertised jobs.

The significance of teachers not joining a school like Westlake Boys is not lost on the school's PPTA chairman, chemistry teacher Robert Gratton.

Westlake, which has been assigned a decile 10, or top socio-economic, ranking from the ministry, routinely takes a substantial swag of As in each year's Bursary exams, and has "relatively few behavioural problems" within its 1800-strong student body, he says.

It advertised three times for a head of chemistry at the end of last year, receiving only one applicant, and could not appoint a head of economics for the first term this year because suitable candidates could not be found.

The same stories can be told by schools in Levin, Dannevirke, Wanganui, Manukau and Hastings, to name a few, especially in the subject areas of maths, English, science, physical education and Maori.

Finding New Zealand-trained middle-management permanent teachers is harder than ever, the schools report, with a growing number of immigrant teachers - mostly from South Africa - plugging the gaps.

Four of Westlake's new teachers are going overseas at the end of the term - they're not even waiting until the end of the year - and the school is in danger of losing more who are constantly tempted by better offers elsewhere.

One such candidate is Nicholas Matenga who, in his first year of teaching, is being run ragged as the head of Maori, coach of the school's top tennis, athletics and rugby teams and other physical education classes.

As a young Maori man who can teach phys ed, he's hot educational property and has already been headhunted, he says. He enjoys his job, but has come into teaching with a $49,000 student debt and says if things don't pick up, he'll be off to teach English in Britain, the United States or Saudi Arabia. On his $35,000 salary he can pay $135 a week off his student loan and it's only just covering interest.

But at least he's staying - for the time being.

Jacques Tuz, phys ed teacher for 12 years, Simon Walter, music and drama teacher for three years, and Michael O'Callaghan, in his sixth year of teaching Japanese, are not staying.

O'Callaghan is fulfilling a personal dream in returning to Japan at the end of the term, but he says his move was also motivated by the fact that a promotion in teaching is "also a demotion. You get a tiny amount of money - around the $2750 mark - for a huge amount of extra work".

He says even if teachers were given an extra $10,000 each tomorrow, it would not make him stay.

"It would be good for the teachers who are staying, but wouldn't affect my decision. What I think would be better would be to see a workload reduction of about a fifth."

Walter is leaving to tour with his band at the end of term, and says he will "miss the kids but not the workload".

He says of the class of teachers he graduated with, only two he knows have stayed in the profession.

Erica Smith, a part-time art and design teacher who has just started at the school, makes $247 a week after tax and uses $70 a week to travel to her job from West Auckland. She says she would go overseas to make more money, if she ever made enough money to be able to save.

Yet if the PPTA is right in saying that retention is a real problem, it may be less correct in its claim over recruitment.

In the past 10 years, the number of people entering teaching has doubled, from 874 in 1992 to 1858 - a provisional figure - this year. The ministry says the number has gone up more than 200 since last year.

Even given the national average of 15 per cent of teacher trainees leaving their studies before graduation last year, many of them going overseas, the number entering classrooms for the first time is bigger than ever.

TeachNZ secondary subject trainee allowances of $7000 to $10,000, available to all graduates and near-graduates who commit to become secondary teachers in targeted subjects, have helped to bolster numbers. The system actively recruits students with degrees in maths, physics, computing (including information technology and communications technology), physical education and te reo Maori.

But most teacher trainees have a social sciences degree, says the ministry.

Even so, with the ministry forecasting that secondary school rolls will peak in 2006 as the teen population swells by around 35,000, there should theoretically be no shortage of jobs.

Almost 70 per cent of trainee teachers found work after graduating at the end of last year - one of the best rates for graduates on record.

Combined with that is the fact that teaching seems to be more of a lifestyle choice than ever before.

The manager of the Auckland College of Education's contact centre, Jan Menzies, says an increasing number of people coming into the profession - the college is the largest trainer of new teachers in New Zealand - are people who have quit the corporate life to make a "society move".

"I would have to say it has increased as a total proportion," she says, although whether these people are more likely to stick at it is inconclusive.

One reason for the jump in teacher-trainee numbers is the number of private training providers that have proliferated since Learning for Life reforms in the tertiary sector were established in the early 1990s. Private institutions, which had struggled to establish themselves before then, flourished with Government funding. Until recently, 20 providers were training teachers in the Auckland area alone.

Now the Government's new tertiary education strategy is about to be implemented, which will make it much harder for private institutions to gain Government finance unless they provide detailed financial and strategic goals to the newly established Tertiary Education Commission.

But most principals who answered the PPTA staffing report at the beginning of this year said the strategy might be too late to arrest the flow of poorly trained new teachers into the system.

The report prompted a slew of comments about quality levels, including concerns about inconsistencies in the standards of training across all institutions and the need to "weed out poor-quality providers" - most of which, they noted, came from the private sector.

To remove faulty trainers, and to pay more to the teachers who remain, may fix some problems. But there are more compelling fears that the profession as a whole has become an unattractive option for high-achieving candidates.

The top students at schools such as Takapuna Grammar, for example, have told the Herald that no one they know wants to teach, citing the amount of work they regularly see their teachers doing, including unpaid extra-curricula work.

One highly regarded Auckland principal who entered teaching in the late 1960s said that when he first went flatting with accountants and lawyers in his salad days, his job was undoubtedly on a par with theirs. He was paid a commensurate amount and respected as highly. "And now ... "

Teachers are still respected to some degree, he says, but not through their pay packets.

Walter from Westlake agrees. He flats with two men in IT and laughs to think of the comparison. "Their pay packets are much bigger, and their jobs seem pretty cruisy to me."