March 5, 2013 | 2
On the evening of October 6th, 2005, I drove a cream-colored pickup along a bumpy, dusty track deep inside Kenya’s Masai Mara National Reserve, just west of the Mara River and less than 10km north of the border with Tanzania and the Serengeti National Park. Scanning the endless field of red oat grass extending from the top of the opposite bank of a seasonal creek, my eyes suddenly tracked to a flicker of movement. I hit the brakes, brought my binoculars to my eyes, and held my breath.
Yes! Finally! Lions! Two adult females were lazing against each other at the edge of the grass. Local rangers had told me months earlier that there were two lionesses living along the creek, but I had not seen any lions during several previous searches of the area. I started to breathe again, and did that little seated dance of joy field biologists do when they are thrilled about something but can’t move too much for fear of spooking the wildlife. But the equatorial sun was setting fast, so I stopped dancing and hurried to get photos and sketches before darkness fell.
I was determining the number of lions in the reserve at the time, and I needed the photos and sketches to establish whether or not these were new lions I had not seen before. Lions are mainly nocturnal and naturally cryptic, live at relatively low densities, can have large home ranges, and often spend time away from their pride-mates. They are also both dangerous to and wary of people. Thus they can’t be counted using traditional ground or air transects.
Instead, counting lions accurately involves identifying them individually – using whisker spots of all things. The dark spots at the base of each whisker on the side of a lion’s face form a unique pattern. While other markings such as scars can change over time, whisker spot patterns are fixed and can be used to identify lions throughout their lives.
I managed to get a few photos and to sketch the whisker spots before dark, and then happily drove the 15km back to my tiny tent in the public campsite, where I could compare the new photos and drawings to the others I had amassed during my study. The lionesses had whisker spot patterns I had not seen before, and I named them Naomi and Nafula. They were the only adult females in the N pride in 2005.
I spent the better part of 9 months – and 1085 hours in that pickup! – searching for and identifying lions throughout the 1500 km2 reserve in 2005. Although finding lions is always a thrill, searching for them, and, once you do find them, trying to photograph and sketch each side of their faces, are perhaps the most tedious things I have ever done as a field biologist. And while I did manage to determine a population estimate from the data, the research wasn’t exactly cutting edge science. I certainly didn’t ever expect it to become part of a study proposing a paradigm shift in carnivore conservation.
But today, seven and a half years later, those data – along with lion numbers from 41 other sites in 11 countries across Africa – are published online in the journal Ecology Letters. And the results do indeed suggest that we need to rethink the approach to wildlife management in many places if we want to have lions around 20 – 40 years from now.
Lions have disappeared from almost 80% of the species’ historical range, and perhaps only 20,000 to 40,000 individuals exist today. Although they attract significant revenue as a safari tourist attraction, lions come into conflict with people and livestock increasingly often. With such negative overall trends for the species, Craig Packer, Distinguished McKnight Professor at the University of Minnesota, director of the Serengeti Lion Project, and the world’s foremost lion expert, decided it was time to bring all available lion count data together to see if we could determine whether variation in management practices and other conditions were related to changes in lion numbers.
The list of variables considered for their effects on lion numbers in each site included whether or not the site was fenced, the management budget, the geographical location, the human population density, governance, site area, whether or not the site was managed by the state (as opposed to privately), and whether or not the lion population was subjected to trophy hunting.
It turns out that lion numbers are highest (closest to expected densities) in the sites that are fenced and have the highest management budgets. Private management also positively affected lion numbers within fenced reserves, whereas the surrounding human population density and trophy hunting impacted negatively on lion numbers within unfenced reserves.
Most striking is the fact that it currently costs more than $2000 per km2 to maintain a lion population at just half it’s estimated carrying capacity in an unfenced reserve, but only about $500 per km2 to maintain a population at 80% of carrying capacity in a fenced reserve.
So what exactly does this mean for lion management and conservation? It seems pretty obvious that to successfully conserve lions we will need to spend a lot more money, and we will need to erect barriers between lions and the increasing human population, which is a paradigm shift back to fortress conservation from current efforts to promote coexistence between lions and people.
Packer thus cleverly titled the paper “Conserving large carnivores: dollars and fence,” and wrote the following in an email to me a few days ago:
“Fortress conservation is clearly the best option, but it can only be employed in ecosystems with well-defined limits. Lions are also found in migratory ecosystems that overlap with pastoralist grazing lands. These areas cannot be fenced without destroying the wildlife migration or ending a traditional way of life. Hence some sort of coexistence may be necessary – but these migratory systems are so large and the conflict mitigation projects so limited in scope (yet so labor intensive) that it is hard to see how coexistence can be sustained in the long term over an appropriate geographical scale.”
“I think it will surprise people to realize just how incredibly expensive lion conservation will be. I expect that a lot of people will be horrified at the prospect of more fences. For anyone who hates fences: I invite you to live in areas with lots of man-eating lions and crop-raiding elephants.”
Herding cats must be nothing compared to herding 57 biologists, ecologists, naturalists, and conservationists who count cats. The results of perhaps 500 annual lion counts – many of them involving those whisker spots – are included in this new paper, as well as decades of other data. It took Packer and several colleagues four years to organize all of us and our data, and to then analyze everything, write the paper, deal with feedback from many of the coauthors, add more sites and variables, reanalyze the data, rewrite the paper, submit the paper for publication, reanalyze and rewrite again, and finally get the paper accepted and revised for publication.
Although it took four years, the paper has been published at an important time. Several animal welfare and conservation organizations recently petitioned the United State Fish and Wildlife Service (USFWS) to list the African lion as endangered under the Endangered Species Act (ESA), and USFWS is officially considering the petition (read the Federal Register here). One of the consequences of an ESA listing is that the importation of lion trophies to the USA would become illegal.
Packer has given our results to and discussed the paper with USFWS as they consider the listing during 2013. He summarizes,
“Sport hunting had a negative effect on lion population growth rates in the unfenced reserves: lions in unfenced National Parks in Zimbabwe and Tanzania suffered from excessive trophy hunting in adjacent hunting blocks. However, hunting did not have any measurable consequences in the fenced reserves – presumably because of high management standards in these areas.”
“As currently practiced, trophy hunting does not raise sufficient revenue to pay the necessary costs of lion conservation. Most hunting blocks in Africa are unfenced, and our analysis showed that it costs about $2,000/km2/yr to maintain lion population at 50% of their potential. Trophy hunting rarely generates even $1,000/km2/yr, and, in most countries, hunting revenues are only a few hundred dollars per square kilometer per year. Hence, trophy hunters cannot justify their claims that hunting is an effective conservation tool.”
“On the other hand, if lion hunting is banned and if a lion ban were to cause many companies to go out of business, much of this land would likely be converted to agriculture. Hunting may not be good enough, but it may often be better than the alternative.”
The analyses in our new paper strongly suggest that the threats of an increasing human population and the associated habitat loss and human-lion conflict trump the threat of trophy hunting. Poorly managed trophy hunting is problematic, but could eliminating hunting (and whatever value it affords lions) cause more harm than good?
We’ll see what USFWS have to say when they decide whether or not to proceed with an ESA listing.
Whether or not hunting is banned, and whether or not lions are listed on the ESA, the main threats to lion conservation will remain. The bottom line is that we are facing a daunting problem that must be addressed urgently if lions are to persist.
Packer concluded his recent email with these take-home messages:
“There is no way to perpetuate more than a small fraction of remaining lion habitat. There is not enough money in the world to pay the necessary costs of lion conservation. Given these limits, it is urgent to start focusing on the few key ecosystems that could hold large viable populations into the next century.”
“Partnerships must be sought with large agencies such as the World Bank to erect wildlife-proof fencing. (Hey, World Bank: you build infrastructure don’t you? Fences are infrastructure aren’t they? Wildlife tourism can generate sizable revenue for developing nations – why not build a fence around the Selous?) The Selous may be the size of Switzerland, but it would only cost around $30 million to fence the place and then it could be managed for only $500/km2/yr (to keep lions at 80% of their potential) instead of keeping it unfenced and trying to raise $2,000/km2/yr (to keep lions at 50% of their potential). Compared to some of the other things that the World Bank does, a fence around Selous sounds like a bargain.”
“Conservationists should also stop staking out their tiny separate fiefdoms and instead cooperate with each other to save the high-priority sites. Funding needs to be pooled together to make a dent in the problem. Wake up, people, it will be impossible to save all the remaining lions. Don’t stretch yourselves too thin so that even the Serengeti, Selous and Okavango are starved of necessary cash. Crunch time is now – we all knew this would happen some time. Welcome to the 21st Century.”
I revisited the N pride area just two months ago.
There has been no systematic monitoring of the lions throughout the Mara since 2005, and I have no idea how lions are doing overall. Lions have been speared and poisoned along the border of this unfenced reserve, and sightings have decreased in at least one edge area. But back in the heart of the reserve, I was greeted by a pride of at least 18 lions, including new cubs.
Naomi and Nafula are probably long gone – not surprising because they were already quite old in 2005 and lions do not live much past the age of 8 or 9 under the best of circumstances. But these lions are likely their descendents, raising granddaughters and grandsons, even great grandcubs now.
As I sat in the car with my own young children, watching those cubs nurse, sleep, and play amidst the rest of the pride, I again felt light years away from the front lines of conservation and wildlife management. But perhaps this pride will eventually serve as evidence again some day, just as the whisker spots of their ancestors do today. I personally hope that they will serve as evidence that when left to live in a protected area far from people, lions can not only survive, they can flourish.
Images: copyright Stephanie M. Dloniak.
Related at Scientific American: