OTTAWA - Canada's census takers were welcomed by a record number of First Nations in 2006, but some of the country's most populous reserves still shunned the process.

Details on the national number of people who identify as aboriginal -- North American Indian, Metis (mixed native-European descent) or Inuit -- will be released Tuesday by Statistics Canada. It's the first of four sweeping census reports coming out this year on everything from aboriginal education to income and labour.

While native participation in the census has increased, thousands of aboriginals weren't counted because they're homeless, in jail or refused to give their consent.

"We are not Canadian citizens," says Chief Clarence Simon of Kanesatake, the Mohawk community that stared down soldiers during the 1990 Oka crisis. His reserve is among 22 not included in the most recent census snapshot.

"We are North American Indians. And that is something they have to understand," he said of Statistics Canada officials who reached out to First Nations.

"They already know how many native people are registered."

Accurate figures are vital because they help set federal funding for native housing, health, education and social services negotiated in treaties.

Today, many cash-strapped bands mistrust how census data might be used. They also note that Indian Affairs already collects yearly membership numbers.

"Everything under the sun has been studied," says Chief Don Maracle of the Tyendinaga Mohawk Territory west of Kingston, Ont.

"They have statistics on education, on health, numbers, age groups."

For years, Maracle said, First Nations were denied rights that Canadians take for granted -- including the right to vote.

"The mindset of a lot of Iroquoian people is that they will not participate in the census. We're not going to politick with them to change their mind."

"It's not the most pressing issue that council has."

Unresolved land claims, unsafe drinking water and extreme poverty are higher priorities, he said.

By law, refusal to fill out the information forms calls for a $500 fine or three months in jail. Fifty-two cases were referred to the federal Justice Department and seven people were convicted after the 2001 census.

Anil Arora, director general of the census program branch at Statistics Canada, stressed that 98 per cent of First Nations co-operate. His department prefers outreach to legal action, he said in an interview.

Census staff made special efforts to count people in homeless shelters, he added. People in institutions such as jails are counted although specific identity characteristics aren't separated out.

Still, sampling techniques allow data to be adjusted to provide good results, Arora says. "Our estimates are very robust. The argument that we miss a tremendous number -- we don't see that."

Across Canada, the data-gathering extravaganza provides as detailed a picture as possible of the country's social and economic fabric. But despite special efforts to employ native liaison officers and develop products that make use of resulting statistics, aboriginal people were once again under-counted.

Kanesatake, with about 2,000 members, is among the smaller of 22 reserves not reflected in the 2006 census. Others include the Mohawks of Akwesasne and Kahnawake in Quebec, Little Buffalo in Alberta, Esquimalt in B.C., and the Six Nations of the Grand River near Brantford, Ont. -- Canada's largest band with 22,649 members according to the federal Indian Registry.

Thousands more people weren't specifically noted as aboriginal because they had no permanent address or were behind bars.

"We think it's a severe under-count," says Peter Dinsdale, executive director of the National Association of Friendship Centres. "But that being said, they're still the strongest numbers that we have."

The census reach is improving, says Nancy Zukewich of Statistics Canada. There were 30 reserves incompletely enumerated in the 2001 census, down from 77 in 1996.

"We just don't arrive on the doorstep once every five years and ask them to fill out a census form," Zukewich said in an interview. "We've been developing an ongoing relationship with aboriginal organizations and communities."

"We also have ongoing discussions ... about their data needs. And we're making big efforts to try to give information back in a way that's easy to use and understand."

Inuit Tapiriit Kanatami, Canada's national Inuit group, works closely with Statistics Canada.

"Census data has been used for a variety of advocacy purposes," it said in a statement. "For example, information on crowded homes in Inuit communities was presented to the United Nations special rapporteur on housing."

Just over 1.3 million people reported having native ancestral ties in 2001, or about 4.4 per cent of the national population. That was up from 3.8 per cent in 1996.

Not everyone who declared such roots said they now consider themselves North American Indian, Metis or Inuit, however.

The 2001 census recorded 976,305 people who identified themselves with one or more of those groups -- 22 per cent higher than in 1996. In total, 3.3 per cent of the Canadian population identified themselves as native, compared to 2.8 per cent five years earlier.

That growth is due in part to an aboriginal birth rate that's about 1.5 times higher than the national average. Another big factor: it's increasingly chic to be native.

"As people take more pride in their aboriginal ancestry they're more likely to report it," says Dan Beavon, director of strategic research for Indian Affairs.

The opposite also holds true, he explained.

"After World War II, the German population -- according to the census -- disappeared because people weren't willing to admit they were German."