Alexander Bratskovsky
On February 4, scientists monitoring lion populations in Uganda used nighttime drone thermal imaging to capture two lion brothers, whom the Uganda Wildlife Authority has named Jacob and Tib, swimming across the predator-infested Kazinga Channel, likely to search for mates. While lions have previously been reported to swim short distances, Jacob and Tib swam about 1.5 kilometers (nearly a mile), the longest swim ever recorded by the Uganda Wildlife Authority. New paper It was published in the journal Ecology and Evolution.
“fact [Jacob] “That its sibling, the Tibu, has survived so long in a national park that has experienced so much human pressure and high rates of poaching is an achievement in itself. Our science shows that the population has been almost halved in just five years.” Co-author Alexander Bratskovsky said: Professor at Griffith University, who has been working with the Ugandan government since 2017 To monitor “His successful swim through a waterway infested with hippos and crocodiles is a record-breaking feat and a testament to his incredible resilience in the face of such dangers.”
According to Bratskovski, Jacob and Tib’s incredible feat is likely the result of increasing pressure from human encroachment. 2020 Papers The researchers propose a new survey method that can be used more widely to provide early warning of lion decline. Their method revealed alarming movement parameters for both male and female lions in Uganda’s Queen Elizabeth National Park. Home ranges had expanded to 3.27 km for males (a 400% increase) and 2.22 km for females (a 100% increase), likely a response to systematic prey decline, for example due to poaching. Also, the sex ratio was dangerously skewed, with a highly unusual ratio of 1 male to 0.75 females.
“In African lions, males already pay a high price for large and impressive sexual signals, taking on great risks to find mates, establish ownership, and protect lionesses and their cubs,” Braczkowski and his colleagues write in the new paper. “This situation is likely to be exacerbated by limited access to lionesses and/or significant human pressure.” That’s what led to the record-breaking swim.
Lion brothers Jacob and Tib brave hippos and crocodiles to cross the river. Photo by Alexander Bratskovski.
Braczkowski and his team think that Jacob and Tibu were likely searching for a lioness with whom they could mate. Apparently, shortly before their record-breaking swim, they had lost a fight with another male lion for the affections of a lioness, and decided it was worth the risk to look for a mate on the other side of the channel. There is actually a small bridge connecting the two sides of the channel, but it is always manned by humans (two armed guards), which may have discouraged the lions from using it.
This isn’t Jacob’s first time overcoming adversity. The lion is something of a local icon, famous for surviving many accidents that would have killed his less sturdy, amputee-like companions. Yes, Jacob made the incredible swim on three legs. “Jacob has had an incredible journey. He really is a cat with nine lives.” Bratskovski says.“I would bet everything I’ve got that this is the toughest lion in Africa. He was gored by a buffalo, his family was poisoned so they could trade lion parts, he was caught in a poacher’s trap, and finally he lost a leg in a wire trap during another poaching attempt.”
There has previously been little evidence that lions are capable of swimming significant distances, but the authors observed lions doing so six times in western Uganda last year. They also searched the internet extensively for other examples. One peer-reviewed paper suggested lions may cross the Kwa-Kasai and Congo rivers, but no solid evidence was presented. The authors found one report of an adult male crossing the 100-metre-wide Zambezi River from northern Zimbabwe to Zambia in 2012, as well as several YouTube videos of male African lions swimming short distances in the wetlands of the Okavango Delta.
While African lions have occasionally been known to hunt crocodiles and hippos on shore, they are much more vulnerable in the water. But “records such as this indicate that, if sufficiently motivated, lions can cross large rivers that are commonly thought of as barriers to connectivity between extant lion populations,” despite the high risk of injury or death, the authors write.
Ecology and Evolution, 2024. DOI: 10.1002/ece3.11597 (About DOIs)
