New way of counting lions is the cat’s whiskers
Alexander Richard Braczkowski, Duan Biggs, James R Allan and Martine Maron
African lions are one of the world’s favourite animals – but their numbers have been shrinking over the past century, especially over the past 30 years. Some scientists estimate that their numbers have halved since 1994.
Estimates of the total population of Africa’s king of beasts vary, but a recent Convention on International Trade in Endangered Species of Wild Fauna and Flora report suggested that only about 25 000 remain in the wild, across 102 populations in Africa.
But the numbers in this report aren’t particularly reliable. Most used traditional survey approaches – like counts of lion footprints, audio lure surveys or expert opinion – and many were not peer-reviewed.
These traditional methods produce highly uncertain estimates. A count using their footprints may give you an estimate of, say, 50 lions in an area. But the uncertainty around this estimate could be between 15 and 100 individuals.
This uncertainty makes tracking how lion populations change from year to year nearly impossible. Our recent review shows that the majority of methods used to count African and Asiatic lions use these less robust methods.
The good news is that better ways of counting lions are being developed. So-called spatially explicit capture-recapture methods are useful for conservation because they tell us not only how many animals live in an area, but how they move in a landscape, what their sex ratios are and even where their highest numbers are.
This method has been used to count tigers, leopards, jaguars and mountain lions for over a decade. But is only now becoming popular for lions. It was first used to count lions in a 2014 study in Kenya’s Maasai Mara.
The lead authors capitalised on a historic way of identifying lions: their whiskers. Every lion in the wild has a unique whisker spot pattern, very much like a human fingerprint.
Recently, we applied this technique in southwestern Uganda, in a region known as the Queen Elizabeth Conservation Area. These lions have a rare culture of tree-climbing. This means they have great local tourism value as each lion raises about $14 000 (R243 000) annually in park fees.
From October 2017 to February 2018, we drove more than 8 000km in 93 days searching for lions. We obtained 165 lion detections. Using individual identifications from photos, we calculated that on average one could expect to find about three individual lions per 100km2, with a total of 71 lions in the entire area.
Braczkowski: Research Associate, Griffith University
Biggs: Senior Research Fellow Social-Ecological Systems & Resilience, Griffith University
Allan: Post-doctoral research fellow, University of Amsterdam
Maron: ARC Future Fellow and Professor of Environmental Management, The University of Queensland
– The Conversation