Why do bucks grunt during the rut?
Bucks grunt to communicate with does, signal their position to other bucks, and sometimes to challenge rivals during direct encounters. Grunts are short, low-pitched calls — roughly burp-toned, lasting about a half-second each. The cadence and intensity changes by phase: short contact grunts in pre-rut, aggressive tending grunts during chasing.
A tending grunt — a buck dogging a hot doe — is rapid-fire and rough, often repeated every few seconds. A contact grunt is single, soft, and low. A snort-wheeze is a separate aggressive vocalization usually reserved for buck-on-buck challenges.
For calling, mimicking a tending grunt during the chasing phase pulls cruising bucks toward the source — they assume another buck has located a doe. Use sparingly and stop calling once a buck commits. See state rut date pages to know when chasing is most likely on your ground.