quiet boy now vocal

In the almost three years we've had Buddy he's rarely barked, likely because he'd been abused. Noonie barks, but Buddy never. Our new girl Penny (Staffordshire Terrier) however is quite vocal. And I guess she's helped Buddy find his voice, because he barks quite a bit now. Penny is very alert and if she hears something outside, she's out there barking and Buddy is right there with her. She's also taught him to play too. During the winter I would catch them wrestling in the snow. More than once I've seen Buddy pin her down. He'll also get right in her face if he doesn't want to be bothered. It's been interesting to see this behavior considering how timid he's always been.