OAKLAND – After his wife, Tara, died of cancer in 2007, Ryan Lilly had to change a lot more diapers, coordinate his four children’s schedules and take on many of the other tasks he’d previously left to her.

“You play a little bit more of the role of the mother and the father,” said Lilly, 35, who works at Togus VA Medical Center. “My wife was a stay-at-home mom, so she was able to be heavily involved in all the things my kids were doing while I was, frankly, working all the time.”

Two-parent families were the norm a few decades ago. Today, there are millions of fathers like Lilly who must pull double duty.

More and more Maine children are being raised in a single-parent household. In 2009, the number hit 84,000 — or 33 percent. That’s up from 69,000 children in 2000, according to Kids Count, a national child advocacy organization.

Most single parents are women, but a significant number are men — 15 percent nationwide in 2010, according to the Census Bureau.

Single parents of both genders probably struggle with many of the same issues, but there are unique challenges for single fathers.

“It’s becoming more common for dads to raise kids or raise a family by himself, but it’s still not out there everywhere he goes,” said Brock Griffin, a spokesman for the National Center for Fathering, a research and education organization. “If you’re in a situation where you’re the only dad and there are a bunch of moms with their kids, it can be kind of isolating.”

Donn Chamberlain, 40, a father of four from Skowhegan, doesn’t know many single dads, but that doesn’t bother him.

His main concern has been making sure his sons are supervised while he’s out driving a truck on local rounds.

“I called family,” he said. “They’ve been the biggest help. My niece lived with me for a while.”

Chamberlain had three sons, including a 6-month-old, when he got divorced more than seven years ago and received primary custody.

Now he has another infant, but it’s a lot easier now with older children, established routines and the baby’s mother living with them.

Chamberlain has taught his eldest son, 16-year-old Justin, to cook and take care of the yard.

“I’m giving him different chores now so he can get some life experience for when he gets out on his own,” Chamberlain said. “He’s my biggest helper right now.”

But it’s not all work.

They go to the park for baseball many evenings and enjoy watching TV and talking together.

Going to games and school events is the best part of being a father, Chamberlain said.

“I just think it’s rewarding to be home with them, be with them and not just visit them once in a while,” he said.

No matter the configuration of a family, it’s important for a parent to be actively involved in children’s activities and the cultivation of their character, said Phil Judd, founder of the Maine Families Network, a new organization that aims to advocate and provide support for parents.

“If that is done intentionally and with grace and kindness and compassion, that child will grow into that expectation, that practice, those customs,” Judd said. “If you’re not intentional, the culture that’s out there generally is not that encouraging.”

Spending more time with his children, for Lilly, is both a necessity and a joy. In addition to wintertime skiing and summers at the lake, he chaperones field trips and attends classroom presentations, things he rarely did before he was widowed.

Single fatherhood remains a work in progress, with adjustments as the children age. Lilly’s oldest is 10 now, and the youngest will enter kindergarten in the fall.

“It does get easier because they’re just able to do more things for themselves,” he said. “Like anything else, hopefully if you work at it you’ll get better at it.”