The demand on schools to provide a growing number and range of activities outside of the classroom is having an impact on cash-strapped schools.
A survey of principals conducted by the Secondary Principals' Council showed that nearly 60 percent had dropped some field trips, 41 percent had dropped some activities with take-home components and 68 percent had made more activities optional.
The council said school operations grants have barely kept pace with inflation.
Bay of Islands College in Kawakawa has a roll of 373, of which 85 percent are Māori.
Its principal John Paitai said end-of-year camps have been scaled-back and class trips are getting harder to fund.
"And if they are part of the curriculum then we just find the money and make them happen, but anything else beside that is just a heck of a lot of fundraising," he said.
"We have got some really committed staff and parents that just seem to be continually fundraising all year."
Bonnie Collins-Bramley is at Ngata Memorial College in Ruatoria where the roll is 130 students, with 99 percent Māori.
She said funding issues for her school were complicated by its isolation.
"And with that comes many many things, and one of them is definitely sports events, and the trips involved to getting the children to get some outside competition and attracting effective staff [to the school]."
Ms Collins-Bramley said it was the students who suffered.
"We've got 130 students and out of that we have got 70 students who are at secondary school and we cannot offer 100 percent to all of those children. We cannot even offer 50 percent of what they would like."
John Paitai, from Bay of Islands College, said schools like his faced a declining spiral, where a lack of resources started to impact on roll numbers - and any fall in the roll meant less funding for operation grants.
"Once you start seeing families leaving because they don't like the environment... You get students leaving and going to other schools where they get better facilities and it is really hard to pull back from that."
Secondary Principals' Association president Sandy Pasley said schools were placed in a very difficult position.
"We want to do the best. I think principals and schools want to do the best for their students and they want to make it equitable for everyone," she said.
"But certainly it is much easier if you can call on a community that can give and donate funds and can raise money through local activities, and international students are also attracted to the higher decile schools."
Ms Pasley said more and more schools were having to rely on fundraising to cover some normal operating expenses.