Lions are threatened across their range, though there are still protected areas that offer these predators a safe haven. This includes the famous free-roaming black maned lions synonymous with the Kalahari.
A recent study on the lion population of the Kgalagadi Transfrontier Park has provided the most comprehensive assessment to date. The results have showed changes in the demographics of the populations, which could be a cause for concern if the trend continues.
Otto Beukes, who has been spearheading the Kalahari Lion project realised in his most recent study that concluded at the end of 2015, that the sex ratio is unique. Half of all adult lions in the Kgalagadi is male – in other lion populations usually only a third of the adults are males. In fact, this is the largest difference recorded in the populations between study periods.
“There were about 25% more males when compared with observations made 20 years ago,” says Beukes.
Today, almost half of all the lions in the park are male. Prior to a study conducted in 2010, populations were biased towards females. However, at the time of the 2010 study, cubs and sub-adults already started showing a skew towards a greater number of males, with 67% and 61% respectively.
According to Dr Sam Ferreira, large mammal ecologist at SANParks, a population collapse is possible if such trends are to continue. “The long term outcome can vary though,” he explains.
Furthermore, Beukes’s study also showed a change in the age structure. Birth rates were lower between 2013 and 2015 when compared to the time between 1998 and 2001.
In that particular study, 0.69 cubs per female per year was born. This has gone down to 0.57 cubs per female annually. Previous studies have also shown that cub survival rate in certain areas has been as low as 5%, primarily due to starvation.
Furthermore, the majority of cubs born are males. Males in particular fall victim to human lion conflict more often. Otto says that this may be as high as 17 individuals per annum in the boundary prides of the park and appears to affect sub-adult males. It happens that lions escape from the park and run into conflict with farmers, especially on the south and southwest of the park.
The study took place over 317 sampling days. During the time period, 1162 lion sightings were recorded by photographing whisker spot patterns. Otto says that they identified 261 unique individuals.
“This method provided for a non-invasive marking technique from which mark-recapture and minimum known-alive estimates could be calculated.”
Beukes says that it will be important to derive estimates of demographics and population size in the future to observe precise trends.
“Drivers of these changes require further investigation to gain insight into potential conservation actions that may secure the persistence of the Kgalagadi lion population.”
Written by René de Klerk– SANParks Times Reporter
Pictures: René de Klerk
Content courtesy of SANParks Times: www.sanparkstimes.co.za