I found this horrifying and I think he doesn't know what he is talking about.
Poor Fero...

Link

That's just vandalism.

what a waste of an old specimen.

i've seen this on old western movies. usually the indians are portayed as resorting to this water source when others are unavailable.

here is some info i found:

http://www.desertmuseumdigitallibrary.org/public/detail.php?id=ASDM08448&sp=Ferocactus%20wislizeni


''Notes


This is the barrel that the Seri and others prefer to use for emergency water; Seris have survived on it for as long as a month. The juice is flat-tasting but not completely harmless. Drinking it on an empty stomach often causes diarrhea, and some Seri experience pain in their bones if they walk a long distance after drinking the juice.''

but i agree, he just doesn't seem to know what he is talking about.

If only he was in Africa and that was a Euphorbia he was decapitating/drinking...

That's unreal. I know it's a show on survival, but couldn't he have just explained what to do in a dire emergency rather than destroy a healthy specimen for the sake of television? I am surprised at Discovery channel sanctioning this.