Hey, a lot of wild animals can really jump, though! Even tame animals can. I've seen cats, dogs and rabbits jump unbelievably high, too.
As for it being black, few mammals are black as a norm for the species (it makes you very obvious to either predators or prey during the day!) When black individuals occur, this genetic mutation is known as melanism. Melanism can either be partial or entire.
You sure it wasn't a partially melanistic version of one of these:
A bobcat.
(The white-tailed deer raises its tail as a kind of 'warning flag' when running away, like a rabbit.)
Bit odd to see either of those in a metropolitan area, but stranger things have happened. Sorry if these look nothing like your description, but seeing as it ran fast details can often get lost or confused in the rush!
Could be a big pet manx cat as well:
Could also be something that has escaped from a zoo/life as somebody's pet, like these non-native animals:
A melanistic serval. Their big ears are used for listening out for prey in long grass (taller than themselves) at which point they leap onto their prey, so they can definitely jump! Rich people keep wild cats like these as pets in America, so I've heard. The tail could've been lost in an accident.
A mara. Best cat/rabbit cross I could think of off the top of my head. Apparently they're often kept as pets, too, which helps the theory.
If it IS something entirely new, ask other people if they've seen anything like it in the area. If they have, then you could be on to something exciting!
I go on
cryptozoology.com's forums for stuff like that. (P.S I know, I know, no link posting, but I really do think it's the best website to discuss possibilities about animals unknown to science. If I have violated the rules, feel free to remove that.)
