I spent the last week in Estes Park, Colorado, where the elk rut is in
full-swing. Several thousand elk descend upon the town outside Rocky
Mountain National Park each winter, and we saw single bulls with harems
of up to thirty cow elk bedding down in fields, wandering through town,
and acting generally oblivious to humans and cars. Every tree in town
is surrounded by wire fence to protect it from elk.
One one drive up into the park, we found this lone radio-collared bull
scent marking a sapling in a grove of trees. He was rubbing the broken
tree stem with the forehead gland between his antlers, and then licking
the tree where he had rubbed. This went on for as long as we watched
him, at least 20 minutes in the same spot.
The mule deer in the area are used to humans, and this one was munching
on vegetation 50 feet off our trail.
The observation of the bull licking where he rubbed with his forehead gland is fascinating. This is perhaps relevant to the debate among trackers about what motivates these animals to "scent mark", with one (unpopular) side believing that they do it to satisfy some bodily sensation, such as to relieve an itch or to gain pleasure, and the other (the predominant view) believing that they do it intentionally to scent mark. Sue Morse wrote in favor of the latter in the most recent issue of Northern Woodlands Magazine.
ReplyDeleteBut if this bull knew he was scent marking, why would he lick it off? Maybe his saliva adds his scent, too? If so, why not lick elsewhere, so as not to mask the scent left by rubbing the forehead gland?
As I've written before, we humans do so many things without having a clue as to how they impact the likelihood of passing on our own genes, that I'm reluctant to assume that animals have any better sense of why they do what they do. Even after a 3 year psychiatry residency, I'm still puzzling over why I do what I do. I think we're all clueless, humans and non-human animals alike.
We'll never know what was in that bull's mind, but your observation suggests to me that he rubbed without understanding that he was "scent marking" and licked it off simply because it smelled and tasted good to him. However, his activity does have scent marking purposes even if they are unrecognized him: He unwittingly leaves enough scent there to let other elk know he was there, which might help him attract females and/or avoid conflict with other males, both increasing the likelihood that he will pass on his genes.