A collared lioness in Laikipia
More than half of the world’s remaining lion range is shared with people and livestock. People represent the major threat to lions in these areas, killing them directly through legal hunting or illegal poaching, or in defence of livestock, and by removing vital wild prey or destroying important habitat. Although counter-intuitive when considering a top predator, it is actually not surprising that many lions are deeply afraid of people.
It is this fear of people coupled with lions’ ability to be flexible in their behaviour, however, that allows lions and people to co-exist. Lions can learn and change their behaviour to avoid detection by people. This vital flexibility in behaviour they exhibit, however, normally involves a trade-off. For example, avoiding areas occupied by people might help reduce a lion’s chance of being killed but permanently avoiding such areas can also limit access to valuable resources.
Our previous research revealed that lions showed some use of areas near guarded livestock encampments - known as bomas in East Africa - at night when people are most likely to be inside their houses and sleeping. What we could not determine was exactly how lions were using these areas around bomas. Our past GPS collar data showed us where a lion was at hourly intervals, and how long it took a lion to get from one point to another. We could see that bomas affected lion movements from over 1.5 km away; lions sped up when approaching a boma and then appeared reluctant to leave, but were they feeding on wild prey? Were they resting? Both of these are beneficial activities. Or were lions simply being drawn in by the inaccessible livestock guarded in bomas, and lying there licking their lips in nervous frustration? The latter could waste valuable energy whilst providing little returns at best, and be risky at worst.
A herdsman in his boma with his herd of cows
Advances in technology and a large collaborative effort between Lion Landscapes, the University of California, Living With Lions and Ewaso Lions made answering these questions possible. Lions were fitted with a collar that works like a Fitbit, collecting many thousands of 3-dimensional data points a day. After analysis, this data allowed the team to distinguish between different but similar behaviours, such as feeding/sleeping/resting but alert. In short, we were able to see not only where the lions were at any one time, but also more accurately map what they were doing.
An example 24-h movement path from a single lion from Suraci et al 2019. Five-minute GPS locations (points) are colored based on the lion’s behavioral state. The location of an active boma (black cross) is shown.
The Fitbit type data sets from 14 lions collected in this study were huge and unprecedented in the amount of detail they gave us but we also combined them with other data sets; all potential kill sites were visited by field teams, creating a large database on collared lion hunting success across the landscape. We also mapped habitat structure and the nighttime location of bomas so we could measure at any time of the night where collared lions were in relation to livestock herds.
We expected that collared lions’ use of areas around bomas would be limited, and when they did use these areas, we expected that they would remain wary, possibly hunting and feeding less, even during the night when people were not active. What the data revealed, however, was quite different.
During the day, when the chance of encountering people was highest, lions did indeed avoid habitat within 2 km of a boma. At night, when the chance of encountering a person was much lower because people were confined to their houses and asleep, lions tended to choose habitat within 2 km of a boma. This supported findings in our earlier research but what were lions doing close to bomas at night? Interestingly lions choose to hunt wild prey and feed more often at night near a boma than any other habitat or time, taking into account the proportion of availability. This may not sound like much but it is encouraging news because it indicates that lions are even more adept at making the most of areas occupied by people than we thought. In fact, study lions seemed to actively access the resources in those areas whenever people were not active.
Herds man walking his cows back to a boma
As the human population continues to grow, even this flexibility shown by lions will be sorely tested but findings in this paper give hope. Areas around bomas are possibly not the negative void in the landscape for lions we feared they might be. If we can ensure that lions have safe havens (e.g. thick bush or steep rocky slopes) to hide and rest in during the day when areas close to bomas are unsafe, if we can make sure that livestock are well guarded to prevent lions killing them, and if we can keep enough wild prey, then lions can and will do what it takes to survive.
For access to the full paper ‘Behaviour-specific habitat selection by African lions may promote their persistence in a human-dominated landscape’ and to learn how lions are better at surviving around people than we thought, please click here.
Comentarios