https://www.rfi.fr/en/africa/2...-africa-conservation



Lions roar when the weather's right, new study in Zimbabwe shows

Issued on: 14/03/2021 - 14:19


Text by:
Ryan Truscott
4 min

Lions roar more frequently when they are near to water, when it's humid, and on calm windless nights, a new study of nearly 1,000 big cat roars in Zimbabwe has found. The data gained from custom-built collars is helping scientists better understand the animals' habits, and the threats they face.



The study using new technology developed by researchers from the University of Oxford was undertaken in the Bubye Valley Conservancy, a privately-owned wildlife sanctuary in the arid south-west of the country that is home to around 500 lions and other members of the Big Five.

The researchers mapped the locations and climatic conditions behind 990 roars -- and found water and lack of wind were among factors that played a big role.

“Water has been shown in previous studies to be a key resource for lions. It supports prey. It can also be used for breeding sites,” said Matthew Wijers, a post-doctoral researcher at Oxford’s Wildlife Conservation Research Unit and lead author of the study published in the current edition of the journal Animal Behaviour.

“I personally encountered many lions giving birth to cubs along the river lines. So I think those features in particular are high-value resources that they try and protect.”



Discovering how often lions roar near water -- where that water is within their home range -- still came as a surprise.

“It makes sense in theory, but to actually see that shown in the data is interesting,” Wijers told RFI.

New way to detect roars

To gather the data the scientists had to think out of the box. Audio recording devices are heavy on batteries, and run flat within a few days. So the research team used custom-built accelerometer biologgers attached to collars fitted on the lions that were able to gather data over a much longer period. When lions roar they move their heads and necks, and those movements are captured on the biologgers.

The research team then developed a computer algorithm that automatically matched the movement data with roars, and the precise locations of the lions when they roared were pinpointed by GPS devices also fitted to the animals’ collars.

"I’m really glad it worked because it does open up this new way of detecting roars,” Wijers said.

Nine-hundred and ninety roars later, he and his team made several important findings.


One was that lion roars were made more frequently in the early evening, continued throughout the night and peaked shortly before dawn. Another was that lions avoided roaring outside their home ranges within the 850,000-acre conservancy.

"This avoidance behaviour can be attributed to the increased costs of engaging in conflict with other territorial males and the reduced benefits of vocalizing away from owned resources," the researchers wrote in their paper.

It was also found that lions like to roar when air temperatures are low, humidity high and there's not much wind.

Populations in decline

Cool, humid air allows sound to travel further than warm, dry air, while excessive wind “masks” the frequency bands that roars travel in, Wijers explained.

"High winds create a lot of noise so in choosing to avoid those periods they obviously recognise there’s not a lot of benefit in doing so,” he said.

"The atmospheric and weather conditions mentioned in the report definitely does play a role in the acoustics of roaring," said Norman Monks, head of the African Lion and Environmental Research Trust, a conservation group based in Zimbabwe's resort town of Victoria Falls.

Monks, who was not part of the study, told RFI: "I think that this study is very sound and interesting and confirms scientifically and statistically what many of us bush scientists have suspected from casual observation."

Knowing where and when lions are likely to roar will help researchers to know where to set up recording devices, known as passive acoustic monitoring equipment, on trees. This is a less intrusive way of gathering information on lions than putting collars on them.

Africa’s lion populations have declined dramatically over the last century mainly due to habitat loss, and from conflict with humans whose livestock they sometimes prey on.

Keeping tabs on their numbers and their movements plays a key part in conserving these iconic animals.

Interesting study.

But University of Oxford again collaring lions for study in an active hunting conservancy? Hope they didn’t name them too...

Has anyone else seen a lion "shock roar" like a turkey "shock gobbles?" Very consistent with the study, the conditions matched. Was cool, humid, kind of foggy in Simanjiro in March 2012. Buffalo literally everywhere coming out of the park and lions behind them. At first good light first morning in camp, I shot a sighting shot, which was immediately answered with a roar. From not to damn far either.

Lions roar when they kill and to assert area dominance or to indicate their location to the presence of other males. They tend to roar more often in the colder months and not so much in warmer weather.

In the Kafue, they tend to roar early morning whether humid or not.

Just my 30-year observation.

quote:

Originally posted by lavaca:
Has anyone else seen a lion "shock roar" like a turkey "shock gobbles?" Very consistent with the study, the conditions matched. Was cool, humid, kind of foggy in Simanjiro in March 2012. Buffalo literally everywhere coming out of the park and lions behind them. At first good light first morning in camp, I shot a sighting shot, which was immediately answered with a roar. From not to damn far either.

Interesting but never come across this before.

Could have been a total coincidence I suppose as all the conditions were right. But it sure seemed like the roar was in response to the shot.

Turkeys in the States will "shock gobble" in response to a load noise. Some guys use a coyote howl or an owl hoot, but other supposedly less sophisticated, just honk their truck horn or slam the truck door. Both seem to work. Wondered if the same was true of lion.

quote:

Could have been a total coincidence I suppose as all the conditions were right. But it sure seemed like the roar was in response to the shot.

I would settle for sheer coincidence and the "scientific" theory about weather conditions being right is a load of crock.

If a Lion wants to roar it will so do, weather or water be damned as it is a means of communication or announcing territorial rights.

I shot one of a pair of brother lions one year in the southern Selous in Tanzania.

It was about twenty years ago. He was a huge lion, but a bit too young to take by today's standards.

His surviving brother roared for a half hour or so every night near our camp for several days.

I'm pretty hard-nosed, but the roars were so mournful and continuous that they made me feel guilty.

They also roar when they're just pissed off. Had that happen a few times. Once when we were looking for a good tree to hang a bait and lo and behold, they'd killed a buffalo in the korongo right below where we planned to hang the bait. Another couple of times tracking a lion. Every time we bumped him.

I still believe that lion in Simanjiro roared in response to the rifle shot.

In Sept 2012 we were on a 21 day cat hunt on the Luangwa river. On 18 of the 21 nights the lions would roar of and on throughout the night. I don't know how that meshes with the article but we loved it. They were camping out about 300 yards down river from our chalet. At one point I got up in the night to relieve myself and they were really going for it. I yelled for them to shut the !@#$ up and to my great surprise they went quiet and didn't start up again until much later.

Mark