Fun fact: The question "Do giraffes get hit by lightning more than other animals?” is one of the most liked posts ever shared on Reddit. While the idea that the world’s tallest animal may act as a lightning rod is not new, and it’s certainly known that giraffes have been killed by lightning, scientists have only now described the circumstances in detail for the first time.
Conservation scientist Ciska Scheijen, who has been studying giraffes at the Rockwood Conservation in South Africa for the last year, has described two cases of what appears to be death by lightning in a new paper published in the African Journal of Ecology. Though Scheijen points out these are just observations because she was in the right place at the right time, she hopes it will inspire further research into the effects of lightning on giraffe deaths.
On February 29 this year, Rockwood experienced a heavy but brief thunderstorm, with lightning and heavy rainfall. The day before, the park’s herd of eight giraffes had been seen together. The day of the storm prevented observations, but on March 1 only six were seen, something Scheijen says is unusual for this herd. The next day they found two of the herd – a 5-year-old female and a younger female – dead, a few meters apart.
Because they were found not far from where they were observed the day before the storm, it was likely they died during the storm. But on closer inspection, they found a large distinctive fracture in the skull of the elder giraffe, where the right ossicone – the horn-like knobs on top of giraffes’ heads – met the skull. This suggested a direct lightning strike.
Curiously, they reported no singe marks on the carcasses, a sign seen in other animals that have suffered a direct strike. Scheijen and Rockwood ranger Frans Moleko Kaweng did report a strong smell of ammonia and were surprised the carcasses hadn’t been scavenged despite lying there for a day and a half. However, this does in fact match a previous 2014 study that showed a delay in post-mortem scavenging of five days after a giraffe had been struck by lighting, as well as a smell of ammonia. In that study, the dogs of a local farm refused to go near the carcass, so the smell likely kept scavengers away.
There are four ways lighting can kill an animal: direct strike, side flash (near an object that is hit by lightning), step potential (a discharge of lighting in the ground), and touch potential (when part of the body makes contact with a stricken object while also still touching the ground).
Scheijen suspects that because the giraffes were not near any tall trees, the ossicones of the oldest, and therefore tallest at more than 2 meters (6.5 feet) tall, female was the highest point of contact for lightning in the area and was hit directly. The younger female found 7 meters (23 feet) away was likely the victim of side flash or step potential.
"I would not say the ossicones per se act as a lightning rod, but the towering height of the giraffes could," Scheijen told IFLScience. "If they are the highest point in the vicinity, then chances may be high that they are the ones at greatest risk in the area to get struck by lightning."
While giraffes’ height makes them particularly vulnerable to electrocution by lightning, it’s not clear if they have adapted to avoid this. Previous as-yet-unpublished observations by Scheijen note that giraffes walked approximately 13 percent shorter distances during rain compared to when it’s dry, suggesting that giraffes do adjust their behavior in response to the weather. The fact giraffes are not found more often killed by lightning could be because they know to shelter under larger trees, but there is no clear evidence of that yet.