PORTLAND, Maine (AP) — The number of homes with same-sex couples has grown nearly 60 percent over the past decade in Maine, according to census data released as same-sex marriage advocates gather petitions that could lead to the state’s second statewide referendum on gay marriage.

Data released Thursday by the U.S. Census Bureau show that the number of same-sex households grew 59 percent from 3,394 in 2000 to 5,405 in 2010 in Maine.

EqualityMaine, which is leading the gay marriage petition-gathering drive, said reasons for the increase in same-sex households are that the Census Bureau made a greater push to include the data and because gay couples are less leery of discussing their sexual orientation.

“People are falling in love, forming families and feeling much more comfortable about giving that information to census takers,” said spokesman Timothy Rose.

All told, same-sex households account for about 1 in 100 of Maine’s 557,219 homes, similar to data previously released in Vermont and released Thursday in New Hampshire.

The data shows a continuing move away from the so-called nuclear family — a husband, wife and children — but the trend may be slowing as the gay rights movement along with other societal shifts continue to mature, said Luisa Deprez, a professor of sociology and women and gender studies at the University of Southern Maine.

Deprez suggested households are stabilizing after wild pendulum swings. “What we’re starting to see is a more stable version of what our society is going to look like,” she said.

The number of homes where the couples were two women grew faster — 1,900 to 3,257 — than homes with two men, which grew from 1,493 in 2000 to 2,148 in 2010, according to the census. Nearly 1,000 of those homes reported having their own children living in the home in 2010, the census said.

Cathy Plourde of Portland, who this year married her partner Kara Larson in Vermont, said she attributes the entire increase in the number of same-sex households to gay couples feeling safer about discussing their sexuality and feeling that the census data holds more relevancy.

“I don’t think that there’s this upswing in people who are not heterosexual choosing to live together in a life-partner way,” she said. “It’s not catching.”

Maine voters in 2009 overturned a bill passed by the Legislature that would have legalized gay marriage.

Last month, gay marriage advocates announced that they’d be gathering the 57,000 signatures necessary to put the measure to a state vote again in Maine. EqualityMaine said it will decide in January whether to submit the signatures to put the measure on the November 2012 ballot.

Rose, from EqualityMaine, said two recent polls show enough people have changed their minds since 2009 that gay marriage would succeed if it’s put to another vote.

The Rev. Bob Emrich, chairman of the Christian Civic League of Maine, which opposes gay marriage, said the percentage growth in same-sex households may sound impressive, but he said the overall numbers are small. He doesn’t think the new census numbers are relevant to the debate.

Send questions/comments to the editors.