Howl of the Naturalist

Jeremy’s attempt at a howl for the Naturalist’s opening dialog got me thinking. A croc doesn’t howl. Neither does a gazelle or rhino. The letters page was very clear that the Naturalist can’t just assume different animal forms willy nilly so why is he howling. Both crocs and rhinos bellow and I think gazelles may “trumpet” or “bugle”, but don’t hold me to that. So what gives? Any theories?

He is a crocodile with extraordinary powers. 

Someone stepped on his tail.

He was in a hyena form for a time. Apparently hyenas do howl?

http://hyenatalk.weebly.com/meanings-behind-the-vocalizations.html

Maybe he's a fan of Allen Ginsberg