African lion numbers are being overestimated by survey methods
Griffith University press release.
Two Griffith led collaborations published this week indicate that Lion populations in Africa may be lower than current estimates suggest. The research is published in Ecological Solutions and Evidence .
The research, a collaboration involving University of Queensland and Griffith University, published in Frontiers in Ecology & Evolution,and Ecological Solutions and Evidence, found that current lion counting methods for research/conservation purposes may be overestimating lion numbers and densities.
Lead author Mr Alexander Braczkowski, a member of the Resilient Conservation Research Group at the Environmental Futures Research Institute, Griffith University discovered that only monitoring methods that identify individual lions directly provide an accurate understanding of lion numbers, density, sex ratio and sex specific territory range.
“African lions are one of the world’s most loved animal species and for that reason they garner both conservation attention and funding,” Mr Braczkowski said.
“Yet some experts believe that their populations have experienced a 50 per cent decline since 1994 when, coincidentally, Disney’s The Lion King was released.”
Current calculations are that between 20,000 and 30,000 remain in the wild, scattered across 102 populations in Africa, however, our research suggests that these numbers may be substantially lower.
“Most African lion abundance and density estimates are based upon track counts, audio lure surveys and expert solicitation – which are simply not informative enough to understand how lion populations are doing over time.”
According to Mr Braczkowski, as outlined in Frontiers in Ecology & Evolution, the methods being used to calculate lion abundance and density are lagging behind those adopted for other big cats, such as tigers, leopards and jaguars.
“Only by using long term surveys that use photographic methods to identify individual lions can you accurately track population size, density and sex-specific movements.”
“Monitoring these parameters over time provides important insights into population health, that current methods like audio surveys or track counts, can’t. For example, large home ranges and skewed sex-ratios, can signal prey depletion and imminent population collapse.”
“This technique, developed in the Maasai Mara by co-authors Dr Nic Elliot and Dr Arjun Gopalaswamy, directly incorporates data on lion identities and how they move in the landscape into a model of lion density. This is analysed with the aid of powerful computers.”
In their second research paper this week, Mr Braczkowski and colleagues assessed the ability of this technique to better understand the status of lions in Queen Elizabeth National Park, Uganda.
“This was the perfect place to use this novel approach since lions in Queen Elizabeth National Park which spend a lot of their time up in trees, and it is relatively straightforward to get good pictures of them,” said Mr Braczkowski.
“This lion population also carries great local tourism value, with each lion estimated to raise around USD$14,000 annually.”
“Queen Elizabeth National Park is an unusual site where lions, owing to their unique tree-climbing behaviour are frequently seen by managers and tourists,” Dr Gopalaswamy, Science Advisor, Global Programs, Wildlife Conservation Society said.
“This situation can sometimes give the wrong feeling that the status of lions here is healthy. However, one of the features of the spatial models we used in this study is that they also provide information on movement, which is a very informative for researchers and conservationists.”
Mr Braczkowski and colleagues found that lions in Queen Elizabeth National Park were now moving more and have larger home range sizes compared to the previous study conducted about a decade ago.
“Since larger home range sizes in carnivores are often associated with lower animal densities due to less available prey, this is a concerning trend,” Mr Braczkowski said.
“Dr Duan Biggs, another Griffith researcher on the study added that, “in light of the threat to conservation due to the collapse in tourism in Africa it is now more urgent than ever to have accurate, reliable monitoring of lion population numbers on the continent. Dr Biggs added, “our two studies demonstrate the value of using methods that keep track of lion populations directly”. We urge the conservation and research communities working on the ground to shift their monitoring practices to newer, reliable and direct methods.”
Luckily, it appears that this is starting to happen, with such methods starting to be adopted by the Kenya Wildlife Service and partners to survey lions and other carnivores across Kenya.
You can read the full article for free here:
Ecological Solutions and Evidence (DOI: https://besjournals.onlinelibrary.wiley.com/doi/10.1002/2688-8319.12015)
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