
The giraffe is the world’s tallest mammal with its towering legs and long necks. Their legs alone are almost six feet tall — taller than most humans. Their height is both a win and a downfall. One of those downfalls would be they cannot touch the ground with their heads. This means the male giraffe — called a bull — must “drink” the female’s — a cow — pee to establish if they are ovulating.
As gross as that sounds it’s all true. Unlike cats or dogs, giraffes do not go into heat. They also do not have a mating call, give visual clues, or have a breeding season. In order to figure out if it’s time to mate the bull nudges and sniffs the cow’s genitalia. Sometimes they need to do this a few times before the female giraffe widens her stance and urinates for roughly five seconds into the male’s mouth.
Flehmen Response
Then the bull performs what is known as a “flehmen response” by curling back his upper lip, baring his teeth, and breathing in with his nostrils closed for several seconds. When animals do this they are able to detect pheromones and certain scents through their vomeronasal organ (VNO). Which is an auxiliary olfactory organ located above the roof of the mouth via a duct, behind the front teeth of the animal.
This is very beneficial for animals such as elephants, cattle, dogs, cats, snakes, lizards, goats, and pigs. It is essential for giraffes since they can’t tell if it is time to mate without it.
Harts Observations

Animal behaviorists Lynette and Benjamin Hart published their report in “Animals” on Jan. 19, 2023. Some animals will lick a female’s fresh urine to track if they are ready to mate. However, due to its long neck and heavy head, the male giraffe is unable to do that. If they attempted to they would become unstable and placed in a vulnerable position, says Lynette Hart, of the University of California, Davis.
The Harts observed giraffes in Etosha National Park in Namibia, Africa, in 1994, 2002, and 2004. During their numerous observations, they never saw one investigate urine on the ground. Giraffes have a stronger oral connection to their vomeronasal organ than any other mammal.
Normally the VNO-nose link helps animals detect seasonal plants helping the critters recognize it’s time to breed. However, a giraffe can mate at any time throughout the year. This makes Benjamin Hart, a veterinarian also at the University of California, Davis, believe the VNO-nasal connection may not matter much for the mammal.
Consummation Process
During their research, the Harts witnessed bull giraffes approach the females around 150 times. However, they only saw one approach lead to consummation. Due to their height, the mammals only procreate for a few seconds.
If the female becomes pregnant she will gestate for 400 days before birthing her calf while standing up. The reason she carries her offspring for over a year is so it has plenty of time to develop before it’s born. The infant falls over 5 feet to the ground at birth. Within 30 minutes of being alive, they are able to stand. In 10 hours, they are able to run with their mothers.
These tall animals are able to run as fast as 35 miles per hour(mph) for short distances and walk 10 mph over longer distances.
Without the pee-drinking pheromone detection, the giraffe species would become extinct.
By Sheena Robertson
Sources:
Science News: Why male giraffes drink potential mates’ pee
National Geographic: Giraffe
Biology Online: Flehmen response
Live Science: Giraffe sex is even weirder than we thought, and it involves pee
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Inset Image Courtesy of Jo Dainty’s Flickr Page – Creative Commons License