What's the Difference Between a Kangaroo and a Wallaby?

After I posted the pictures of the kids feeding the wallabies
over the weekend, someone asked a great question. They
asked what the difference between a kangaroo and a wallaby
is. I'm no expert, but I'll give a brief answer here.

We actually went to the Desert Park (zoo) yesterday, so
I happen to have a picture of a Red Kangaroo from our
outing yesterday. The Red Kangaroo is common around
here.

Anyway, like the kangaroo, the wallaby is a marsupial. They
give birth to live, very immature young. There are lots
of different kinds of marsupials in Australia including
wombats, koalas, bettong, bilbies, pademelon, potoroo,
quoll, Tasmanian Devil, various rats, mice and possums. (We
have a number of these in the "nocturnal house" at the
Desert Park where we visit quite frequently here in town.)

Some marsupials are herbivores like the kangaroo, wallabies,
and wombats.  Others are carnivorous like quoll, bibies,
bandicoot and Tasmanian Devils.

Wallabies are smaller than kangaroo. And, just as there
are lots of different kinds of kangaroo, there are different
kinds of wallabies as well. The pictures in my post from a
few days ago are rock wallabies, but there are many other
kinds like the black wallaby, the yellow footed wallaby and
so forth.

Another kind of marsupial, the Euro lives in this area as
well and we see them all the time (especially at dusk when
driving); they're in between the size of a kangaroo and
rock wallaby (and I'm not sure even which they technically
are!)

One more thing, two other commonly known Australian
animals--the platypus and the echidna--are not marsupials.
They are monotremes. They are the only egg laying
mammals. They deposit the egg into her pouch (and the
egg hatches about ten days after that).

Below: The kangaroo enclosure at the Desert Park. The
kids are looking at a Red Kangaroo.