JJ! said:
Another:
Would personally word the text diferently:
and the death of one of the worlds
most endangered species
.
Help Save the Rhino.
Personally, I find that reads much better, and you have correct punctuation (Capital letters and full stops) I believe full stops are an excellent tool to use when attempting to get a specific, simple point across, which of course is what you are trying to do.
I'd also use a different font on the ST poster (I do get mixed up, but you have used a san serif when a serif would have looked better, IT may be the other way round) I'd also use thicker, bolder text.
This is only constructive criticism
Just my 2 cents