Aboriginal peoples are gaining ground in Canada's population, but they are losing their languages.

And their family structure is dramatically different than other Canadian families, with less than half of children living with both their parents.

The rest are in single-parent homes, living with relatives or step-parents, or in foster homes. Indeed, half the foster children in Canada under the age of 14 are aboriginal, according to the National Household Survey.

The survey is Statistics Canada's replacement for the long-form census, which was cancelled in 2010 by the federal Conservatives.

The agency has warned that the voluntary responses to the new survey may under-represent Aboriginal Peoples. Plus, comparisons with the past are problematic, since previous questionnaires were mandatory.

And a variety of reserves refused to participate or simply couldn't participate at all, compounding the data quality issues.

Still, Statcan has adjusted for those problems, and the survey clearly portrays a population that is youthful and growing quickly across the country -- a pattern that could vindicate the focus of federal, provincial and aboriginal leaders on education and skills.

Children under 14 make up 28 per cent of the aboriginal population, compared to just 16.5 per cent of the non-aboriginal population, the National Household Survey shows.

But other research suggests fewer than half of those children will graduate from high school.

And even as the aboriginal population soared by 20 per cent over the past five years to 1.4 million, just 17 per cent of aboriginal people said they could speak in an aboriginal language, down from the 21 per cent recorded in the 2006 census.

There are signs, however, that schooling in traditional languages helps. In 2011, 240,815 aboriginal people said they could speak an aboriginal language, but only 202,495 said it was their mother tongue.

"This implies that a number of aboriginal people have acquired an aboriginal language as a second language," the Statistics Canada documents say.

The survey does not show how bad overcrowding is -- even though federal statisticians have a lot of related information. The 2011 census measured the number of people per household, and the NHS also tracked the relationship between aboriginal children and their primary caregivers.

Overcrowding was the reason behind the state of emergency in Attawapiskat, Ont., 18 months ago. The 2006 census showed a decline in overcrowding, but no progress on replacing dilapidated housing.

More 2011 data on overcrowding in reserves may come this summer, said senior census analyst Jane Badets.

Ontario recorded the largest aboriginal population. By proportion, Nunavut and the Northwest Territories had the largest share of aboriginal peoples.

Among First Nations people, nearly half live on a reserve or settlement. Beyond reserves, status First Nations people tended to live in Winnipeg, Edmonton or Vancouver as well as other cities.

Non-status Indians accounted for a quarter of the First Nations population in Canada, concentrated in Toronto, Vancouver, Montreal and Ottawa.