Finding a mate can be problematic at the best of times. 

But when you're an amputee crossing a vast stretch of water, it can literally be a matter of life or death. 

Jacob, a three-legged African lion, has broken the record for the longest swim by a big cat in the search for a female, scientists say. 

Along with his brother Tibu, Jacob travelled about a mile (1.6km) across dangerous crocodile-infested waters of Kazinga Channel in Uganda. 

The two brothers risked their lives in the desperate pursuit of a female to mate with after hearing her roaring calls from the other side. 

Scientists used heat-tracking drones to track the two African lions as they crossed the Kazinga Channel at Uganda's Queen Elizabeth National Park. 

'It was pretty dramatic,' Dr Alexander Braczkowski, a conservation biologist at Griffith University in Australia, told the New York Times.

'It looks like two tiny little heat signatures crossing an ocean.' 

In 2020, Jacob was caught in a poacher's trap that severed his left hind leg, although he'd been fitted with a satellite collar that let rangers locate him and save his life.

Four years later, Jacob has proved he is strong enough to traverse the Kazinga Channel, which is infested with hippos and crocodiles up to 16 feet in length. 

Crocs can potentially kill lions with a lethal bite – especially in water where the cats are at risk of drowning. 

Lions can swim, but they usually only do so when they really have to – either in the search for food or mates. 

According to Dr Braczkowski, Jacob and Tibu have achieved the longest-recorded swim by lions, covering an estimated distance of somwhere between 0.9 and 1.2 miles (1.5-2 km). 

Although this may seem like extreme effort in the quest for love, mating opportunities for males are getting increasing slim. 

At Queen Elizabeth National Park, males outnumber females two to one, partly because of the deliberate poisoning of lionesses (and cubs) that populations are still recovering from. 

In Africa, lions face threats such as retaliatory killing in response to livestock depredation and poaching for their body parts such as teeth, according to Wildlife Conservation Society (WCS). 

Dr Braczkowski estimates that there are 40 lions at the park today, down from around 70 in 2018. 

There is only one species of lion (Panthera leo), but there are two sub-species – the African lion and the Asiatic lion. 

Globally, populations are described as decreasing and 'vulnerable' by the IUCN red list, the inventory of the global conservation status and extinction risk of species. 

According to a University of Oxford-led study last year, lions are 'increasingly being pushed to the brink' as population numbers continue to suffer 'devastating declines'. 

Although the total population of wild lions in Africa may be estimated at between 20,000 and 25,000 individuals, many of these live within small, fragmented populations at risk of disappearing. 

Jacob and Tibu's ambitious voyage has been described in a paper accepted for publication in the journal Ecology and Evolution.