In the wild, some behaviors go beyond what the human senses can perceive. One such behavior is the Flehmen response, a fascinating phenomenon seen in various mammals, including lions and elephants, that helps interpret important chemical messages. This week, we delve into this intriguing behavior, exploring how it helps animals communicate and navigate the world.
What is the flehmen grimace?
The Flehmen grimace is a behavior where an animal curls back its upper lip, exposing its front teeth, and inhales deeply, often holding this position for several seconds. While it may look like a grimace, it’s actually a highly functional form of communication. This behavior allows animals to draw scents into the vomeronasal organ, or Jacobson’s organ, located above the roof of the mouth. This organ processes chemical signals, including pheromones, providing vital information about other individual’s reproductive status, age and sex.
For the lions of Tsavo, the Flehmen response plays a crucial role in their daily lives. When a lion encounters a scent of interest, particularly urine of another lion, it performs the Flehmen response to gather more detailed information. This behavior is often seen in males trying to determine if a female is in oestrus, helping them make decisions about mating.

The Flehmen response in elephants
Elephants, too, exhibit the Flehmen response, though their approach is a bit different. Instead of curling back their lips, elephants use their trunks. They place the tip of their trunk in or near a substance, often urine, then curl the trunk and raise it, placing the tip on the roof of the mouth where the vomeronasal organ is located. This behavior is particularly common in males detecting the reproductive status of females, but it can also be seen in females when exposed to male musth urine or even semen.
Scent trails and the flehmen response
Elephants also use the flehmen response to gather information along well-trodden paths. Studies have shown that when African elephants travel along regularly used routes, they are highly responsive to olfactory cues left by others. In particular, elephants pay close attention to urine and dung left by fellow travelers. This response is especially strong in solitary elephants, who rely more on these scent cues for navigation compared to those in groups.
There is also evidence to suggest that African elephants may potentially be able to discern the sex and maturity of individuals from urine cues on pathways. Male elephants, for example, are more likely to elicit the flehmen response to urine from adult elephants compared to urine from subadult elephants. This ability to pick up on detailed olfactory information helps them navigate their environment and understand their social landscape.
Super tuskers and reproductive success
The super tuskers of Tsavo, known for their enormous tusks and impressive stature, are in their reproductive prime. Understanding the reproductive status of females and assessing the competition from other males are key components of their mating strategy. The flehmen response is an essential tool in this process, enabling these bulls to gather chemical information that influences their behavior and decisions.
This behavior will help them identify receptive females and therefore not waste valuable energy pursuing, and often fighting for the right to mate, of females that are unlikely to get pregnant. The flehmen response the timing and success of their mating efforts, ensuring that their legendary genes continue to thrive in the wilds of Tsavo.

Flehmen response across species
Interestingly, the flehmen response isn’t limited to communication within a single species. Research suggests that animals may respond to chemical signals from other species as well, indicating the presence of a common element in these signals. For example, goats have been shown to exhibit the Flehmen response when exposed to the urine of various species, including non-mammalian ones.
This cross-species communication highlights the complexity and depth of the animal kingdom’s chemical messaging system, where a simple behavior can convey a wealth of information.
Synchronising births
Flehmen behavior isn’t just crucial for males’ mating strategy; it also plays a significant role in female reproductive synchrony. In species like the sable antelope, females use flehmen to synchronize their reproductive cycles, ensuring that they conceive and give birth around the same time. This behavior is especially important just before conception, where females closely associate with others in the same reproductive state. In herd animals, synchronising births gives the species as a whole a better chance of survival.
Understanding animal communication
The flehmen response is more than just a curious quirk of animal behavior; it’s a window into the intricate ways animals communicate and interact with their environment. Understanding these behaviors not only deepens our appreciation for these creatures but also aids in their conservation. As we continue to study and protect the wildlife in Tsavo, insights like these help us ensure that these magnificent animals can live out their natural lives, free from human threats.
So next time you see a lion or elephant in the wild, look a little closer—you might just catch a glimpse of the Flehmen response in action.