The “blow,” or snort, made by a deer, most commonly the white-tailed deer, is one of the animal’s loudest forms of communication. This sudden, explosive sound serves as a primary alarm signal, immediately alerting any other deer in the vicinity to danger. The sound indicates that the deer has detected something unusual or threatening in its environment, whether through sight, sound, or scent. Hearing this sound means the moment of undisturbed observation is over, as the animal has moved to outright alarm.
The Mechanics of the Alarm Sound
The deer produces this dramatic noise by a forceful, rapid expulsion of air through its nostrils, similar to a greatly magnified sneeze or snort. This physiological action causes the air to vibrate the nasal passages, creating a loud, sharp “whoosh” that can travel a significant distance in the woods. This action is not a vocalization involving the larynx, but rather a percussive sound created by air pressure. The intensity of the sound is often related to the deer’s level of alarm, with a single, short snort sometimes given just before the deer bolts away.
While the sound is often associated with the keen senses of a mature doe, bucks and young deer are also capable of producing the alarm blow. The initial snort is typically followed by a series of repeated blows if the deer remains uncertain of the threat’s location. This deliberate expulsion of air may also serve a secondary purpose: to clear the nasal passages, enhancing the deer’s ability to sniff the air for better scent identification.
Decoding the Deer’s Warning Signal
The primary function of the deer’s blow is to communicate a warning to any other deer nearby, prompting them to become instantly alert and ready to flee. The sound signals that the animal has transitioned from suspicion to confirmed detection of a threat, such as a predator, a human, or an unfamiliar object. This alarm call increases the survival rate of the herd, especially in family groups.
A secondary function is communicating directly to the perceived threat that it has been discovered. By making a loud, obvious noise, the deer is announcing that any element of surprise is gone. This behavior can sometimes cause a predator to abandon the pursuit, as the deer is primed for flight and stealth is lost. The blow is coupled with visual cues, such as the deer stomping its forefoot on the ground, which creates vibrations to alert others. This warning is reinforced by the deer raising its tail, exposing the bright white underside, a visual signal known as “flagging” that is highly visible as it flees.
Appropriate Human Reaction to the Sound
Hearing a deer blow means the deer has pinpointed your location or scent, and your presence is no longer a secret. The most appropriate immediate human reaction is to pause all movement and remain completely still. Any further motion will almost certainly cause the alarmed deer to flee immediately, often taking any other deer in the area with it.
The window of opportunity for observing the animal or moving closer is effectively closed the moment the sound is made. For naturalists or photographers, the best course is to stay motionless and wait for the deer to move away on its own. For those engaged in hunting, the blow is a definitive signal that the position is compromised, and the deer is preparing for an immediate exit from the area.