Dear Charles, Swamp Wallabies often have this rufous colour on the chest and belly. This is a very colourful individual with its black paws and white stripe around the mouth. Great image
I'm confident that this is Wallabia bicolor. When they take flight (especially when startled) they slam the ground when they land in order to warn others of an approaching threat. Did it by any chance make a loud thumping sound as it bounded away?
They're usually very shy and hard to approach (in my experience), taking off at the approach of humans and absolutely bolting from dogs, which is understandable as dingoes are their natural predators. Could this specimen have been habituated to humans?
Great shot by the way. I love the intense stare, grass hanging out of the mouth and adorable habit of clenching their paws that you've captured so well in this shot.