Stalking other dogs

OK a question for the Staffordshire knowledgeable.

Just recently as in the last few days when we are at the dog beach , Rosie has started to zoom in her focus on one dog and stalk it.

She crouches down like a Border collie would and watch it make a move/run and then she will bounce up and go on the chase.

It doesn't stop there, she just wont leave it alone, barking at it growling at it, grabbing it by the collar or the side of neck. It is relentless. I have to either go home or put her on lead.

She has no interest in small dogs or big mastiff/Sheppard size dogs. Its just other staffies or border collie size dogs.

Do staffies normally do the sheep dog crouching thing?

Does any of the above sound normal for a staffy?

That sounds like what Nifty does when she tracks the cat
Definitely like the feline crouched approach.
I think Nifty wants to play as her tail is a wagging blur.

It's not what I would call typical staffie behaviour.

I think I'd be popping her on the lead as soon as you see her start, or even before if you see a dog you think she'll react to, and working to draw her attention to you and away from the other dog. Hopefully it's a habit you can break early.

Misty does this stalk and I don't like it as it looks awful! With her it's because she isn't sure of a dog so it's like she half crawls to cover her stomach. What happens is when we get closer to the dog she stands upright, it's like she is trying to cover herself as she is scared but when she gets near them she sees they aren't going to hurt so she relaxes. The thing we have found is distraction before she goes into the crawl. So we just throw treats and this gets her attention so she can't be nervous if she is snuffling for treats.