I first knew pronghorns were nearby when I heard one of them blow, an alarm call formed by a sharp output of breath. It was 5:30 in the morning and I was walking across a sagebrush flat in the morning half-light. I was approaching a sage-grouse lek when I noticed a group of eight pronghorns off to my right. Their heads were up and alert, watching me.
They blew a few more alarm calls before running across my route, right through the lek holding strutting sage-grouse. Luckily, sage-grouse are used to such antics and only two birds flew up to avoid the approaching hooves. The pronghorns stopped on my left side and milled about with all eyes on me. They blew a few more times and then ran back across the lek, scaring up three more birds. Now I was annoyed as much as the pronghorns.
Then the pronghorns ran again, disappearing over a hill, so I thought that was the end of the saga. Looking through binoculars, I counted strutting sage-grouse males and searched for skulking females. Then I heard another alarm blow close behind me and turned to spot eight heads visible over a slight rise, again with all eyes on me. Finally, the pronghorns turned and fled.
Pronghorns are known for their curiosity, and this trait has been put to use by human hunters. Called “flagging,” both ancient Native Americans and modern hunters have waved an object in the air, drawing curious pronghorns close enough to kill with arrows or rifle.
One variant of this technique was used by ancestral Western Shoshone hunters. They tied bits of hide to a sagebrush where the bits would flutter in the wind. The hunter then hid a certain distance to the side. Curious pronghorns would approach the quivering objects and then circle, where they would come close enough to the waiting hunter to be killed.
Both scientific literature and folk stories abound with tales of pronghorn antelope curiosity, but why would these ungulates approach danger rather than simply running away? It seems to depend on the degree of threat from a predator.
A grave enough threat prompts them to run away, while a slight threat may induce them to actually attack a predator. Pronghorns have been known to chase single coyotes away from fawns.
In between these two amounts of threat is a gray area.
The pronghorns on that early morning saw me as an intermediate threat, the severity of which they were not sure. They wanted to keep an eye on me and determine my threat level. They wanted to make sure they did not lose my location while waiting for a clue of my danger. Approaching and circling me was part of the strategy.
Knowing they could easily outrun me as they could any other predator no doubt emboldened them enough to make this determination. On that early morning, I think they probably decided I was more of an annoyance than a threat before finally leaving me alone.