Elk...blue...green....so lovely
I know from experience that green leaves and a blue sky work well in a monochrome image. The only question is whether the warm tones of the animal would be sufficiently distinct once converted to monochrome. I quickly tried it and saw that indeed they do.
For me the monochrome works a bit better. That's because there is nothing magical about the lighting or the animal that would truly set it apart from other similar images. In that situation, just the fact that very few people make monochromes can sometimes make a specific image perhaps a bit more interesting.
A lot of that has to do with whether the viewer likes monochromes. I do, so take my bias into account.