Nicole Richie and Joel Madden have welcomed their second child, a boy.

"In the middle of night, the very early hours of September 9, 2009, Sparrow James Midnight Madden was born to Nicole Richie and Joel Madden," she announced on her website Wednesday. "He weighs 7lbs 14oz. Nicole, Joel, Harlow [their 19-month-old daughter] and Sparrow are all doing well. Thank you for all of your good wishes."

In February, Madden, 31, took to his band's blog to announce that he and his girlfriend, 27, were expecting again. "What's better than winning an Oscar?" he wrote. "I am so happy to tell everyone that Harlow is going to be a big sister!"

As their family expands, the two — together since 2006 — have no immediate plans to wed.  

"I think for both of us, we are going to do it because we want to, not because that's what you do," Richie told CNN's Larry King last May. "We're going to do it when the time's right."

Added Madden, "We're really focused on our family, and we feel like — we already feel kind of married, you know? Our family system that we have down, we feel like this is a real family and marriage, one day it will come."

Richie's father Lionel also wants them "to take their time."

He told King he knows people who have wed spontaneously "and they broke up five minutes later. I like the idea of 'take your time, get it right,' because you have kids in common.

"I'm more interested in whether they like each other and whether they're best friends," he went on. "Because that means they'll be great parents forever."

In 2008, Richie and Madden launched the Richie-Madden Foundation, a charity that supports families and children in need.