Am I reading this right? Explain what you think
happened to the Black Rhino
population between 2002 and
2004. Did baby rhino's magically
appear?

There are two possible explanations for this (or three if you believe in spontaneous generation).

#1

They were extinct in the wild but still alive in captivity and then reintroduced into the wild.

#2

They were in the wild but no one came across them, that's to say they were very endangered, and thus there were so few that none were seen

#3

They spontainiosly came into existence, this is known as "spontaneos generation" and was a thing a long time ago

then that particular organisms become extinct.

not too sure but maybe in the hot springs.