If you’re out for a stroll in the American West, you might hear a high-pitched, bloodcurdling cry that sounds like the shrieks of the ghostly Ringwraiths from the Lord of the Rings. But it’s not the howl of a vengeful soul that you’re hearing—instead, it’s the mating call of a wapiti, or male elk. For years, scientists wondered how such big-bodied animals could make such high-pitched calls. Now, they may have an answer: After analyzing recordings of the elk bugling calls, researchers discovered that they actually comprise two parts—the high-pitched shrieking that can reach frequencies above 2000 hertz (heard in the video above) and a simultaneous, lower-pitched call around 145 hertz, a more typical frequency for an elk-sized animal. They then dissected a dead elk and found a throat structure that would allow the animal to “whistle” through its nostrils to create the higher frequency noise, they write today in the Journal of Experimental Biology. The scientists suspect that this versatility allows the 315-kilogram animal to create deeper, more aggressive noises in combat situations along with higher-pitched noises that can carry far over the open landscapes of the West to attract mates.