Is Elephant Trophy Quality Sustainable in Botswana's Hunting Concessions?
Is Elephant Trophy Quality Sustainable in Botswana's Hunting Concessions?
Last year Botswana’s Hunting Safari Outfitters told me that they were concerned about maintaining elephant trophy quality in their allotted hunting concessions. I discussed this with them when I addressed the Botswana Wildlife Management Association’s AGM in Maun last September. The following was the gist of my address.
Botswana has a grossly excessive elephant population that I calculate must now number in excess of 160 000. There is a comparatively small number of hunting concessions but they are reasonably large. Theoretically, to maintain ivory size, the number of trophy bulls that can be taken off annually must not exceed 0,5 percent of the population being harvested. This equates to 800 bulls per annum if the country’s total population.
Nowhere near this number of trophy elephant bulls are being taken off. On the face of it, therefore, one might wonder why the outfitters should be at all concerned about maintaining trophy quality? But their concern IS justified.
The problem that they have perceived, but do yet not understand, is linked to the behaviour patterns of elephant populations. ALL wild animal species organise themselves in populations – including elephants – and wild animal populations of all species exhibit very similar behaviour patterns.
A population can be described as: “a group-of-animals of the same species that interact with each other on a daily basis in a continuum; and which breed ONLY within that group.” This does not mean that every animal in a single population necessarily interacts with every other animal in the population – but it does mean that animals in the same population are all linked as in a continuous complex chain.
The Oxford dictionary describes a continuum as being, inter alia, “an unbroken mass”. In terms of this word’s application to a population, it is manifested in the phenomenon called home range.
ALL adult animals establish their own individual home range. A home range is that part of the population’s habitat in which an individual animal obtains its living needs: air, water, food and shelter. Once their home ranges are established, adult animals remain within them for the rest of their lives – unless some untoward event (such as drought, fire, excessive hunting, or human occupation of their habitat) forces them to relocate for dire survival reasons. Even then, many animals will not vacate their established home ranges. They will, instead, remain on familiar territory and die within it. This is more true of older adults than the stronger younger ones.
Individual adult animals gain many survival advantages from living within an established home range. They get to know their home range intimately. They know where water and preferred foods can be found no matter what the season. They know where danger lurks. Some human occupied areas they know, for their own safety sake, they can only occupy at night. They know where to go to evade their natural enemies. They know where not to go because of the existence of a more dominant and aggressive male, perhaps. They know where to drink at a waterhole – at a place where they are least exposed to predation by crocodiles. The survival advantage list is endless.
An important aspect of home ranges is that they are shared with other members of the same population. Home ranges are NOT defended. And individuals will often be found within the same general parts of their home ranges at the same times of every day during the same season of the year. In other words they normally use their home ranges in a regular pattern. Good hunters KNOW this!
To explain this phenomenon better we can equate animal home ranges with human home ranges. A human home range comprises that part of a person’s ‘habitat’ (the city in which he lives) where the individual obtains his or her ‘living needs’. He will, for example, regularly visit the same small number of shops near his home to obtain his essential foods and beverages. He will visit the same petrol stations to obtain the fuel that he needs for his motor car. He will know exactly where the local police station is – in case of emergency. He will have a regular doctor and dentist, and he will know where the local clinic and hospital is located in case he needs medical attention. And he will use the same roads at the same times of every day to commute between his regular place of work and his home. He also does not fight other people that he encounters whilst going about his business within his own ‘home range’. He shares his home range with all other people that he encounters. What he does NOT do is to occupy his ‘whole habitat’ – he does NOT live, on a day-to-day basis, in the ‘whole city’.
Home ranges overlap. One person, for example, may go west from his home to visit his favourite supermarket. Another may go east from his home to visit the same supermarket. The first of these persons may go east from his home to visit his local police station. The second may have to travel west to visit his local police station. In both cases neither person will visit the other person’s police station. Thus will their home ranges be different. Thus do their home ranges overlap. The same things happens with thousands of other people across the length and the breadth city.
This is what we call a continuum. It is how individuals, occupying continuously overlapping individual home ranges, have and maintain a tangible link with every other individual in the same city. They may not see and touch or communicate with each other but the continuum is ‘there’. By comparison, they will not have ANY tangible day-to-day contact with people living in another city.
The home range phenomenon is associated entirely with individuals. Even a husband a wife will have marginally different home ranges. First of all they may have different careers and so visit different places of work every day. One might work the other might not. The husband will go into the gent’s toilet in a supermarket, the wife will not. The wife will go to the ladies’ toilet, the husband will not. The woman will visit a ladies’ hairdresser, the man will not.
Different kinds of home range occupancy phenomena pertain in wild animal populations, too.
A ‘territory’ - by comparison – is that part of an animal’s home range that it uses for breeding. Its huge nest, and the surrounding airspace, represents their territory for a pair of eagles. In the human situation a couple’s home-and-garden is their territory. In both cases these territories will be strongly defended by the occupants against unwanted intrusion by individuals of their own kind.
In the case of elephants, however, bulls do NOT hold down a territory. Instead, in their normal day-to-day social existence, they exhibit a strong rank structure in which there are dominant, sub-dominant and lower ranking bulls. Elephant bulls also live apart from the breeding herds – although they may be in daily contact with the breeding herds at the waterholes. Sometimes, however, they live in an ‘exclusive bull zone’ into which the cows rarely venture.
Elephant social structure is complicated by a phenomenon called ‘musth’ that occurs in the bulls. Musth is an hormonally induced state of high breeding condition that focuses the animal’s attention entirely towards satisfying a ‘lust’ to breed. This happens only once or twice a year. It can last just a few days or several weeks. When an elephant bull is ‘in musth’ it becomes irascible, aggressive and very unpredictable. Other elephant bulls that are NOT in musth, no matter what their normal rank structure might be, avoid confrontation with those that are in musth. Musth bulls break from their normal patterns and they seek out cows in the breeding herds that are in eostrus (the hormonally induced female breeding condition) with which they then mate.
An elephant cowherd, on the other hand, is led by a large and dominant cow – the ‘matriarch’. The other cows in her herd are thought to be the matriarch’s daughters. All the breeding cows are always pregnant and/or they have from one to four calves at foot. A ‘normal’ breeding herd comprises four to five breeding cows – and their calves.
One of the most important aspects of elephant society is that, when they are fully adult, elephants - bulls AND cows - rarely leave their established home ranges. There is a great deal of talk about elephants having ‘ancient migration routes’ and moving from one game reserve to another. In the case of Botswana many people believe that elephant populations move from Chobe National Park, in Botswana, to nearby Hwange National Park, in Zimbabwe, and/or vice versa. THIS DOES NOT HAPPEN.
Individual elephants DO move out of Botswana into Zimbabwe, into Namibia, into Zambia and into Angola. Elephants move from all these places into Botswana, too. The elephant populations from which all these wandering individuals come, however, stay put.
The animals that are on the move are the subadults and the young adults (normally 15 to 30 year-old individuals) that are emigrating from their parental populations. This is a natural dispersal phenomenon that occurs out of ALL wild animal populations of ALL species – especially those living in saturated habitats. The greater the density of the population, the greater is the inducement for these young individuals to move.
They move because they are ‘surplus’ to their parental population. They move because they have not yet established a home range of their own. They move because they can no longer obtain their ‘living needs’ from their natal habitats. In the case of Botswana’s young elephant bulls, they move because a huge pressure is exerted upon them all the time by the mass of higher ranking bulls in their parental population. They move to seek a quieter, less congested and richer pasture elsewhere – where they can set up a more peaceful and more content home range of their own. The females in this age group move for similar reasons – though the social pressure on them to move is not nearly so great.
These are the animals that, in years gone by, set up new populations in ‘vacant’ areas of Africa where no elephants existed. It is one of the natural processes of nature.
Consider the situation as it applies to the human species. This is the same age-group of human beings that migrate all over the world. What are they looking for? They are looking for a better and more satisfying place to settle down! And what do the parents of these human emigrants do? They normally stay put!
And what of those elephants that remain behind – the older parental population? Well, they continue to live and to breed, and to die, in the way that nature prescribes. Older animals that die, or are killed, are replaced by younger animals that thus find a place to live - a ‘vacancy’ - within their parental habitat. Thus, under natural conditions over the millennia, have elephants persisted and/or spread across the countryside.
The biggest inhibiting factor disrupting this natural process is the existence of ever-more-dense human populations. Elephant cow herds vacate even their ancestral habitats when human populations in them exceed 15 per square kilometre (40.sq,mile). The bulls may stay on, for a time, but such habitats can no longer be considered suitable for elephant occupation. The existence of growing human numbers, moreso than fences, cause elephant herds to concentrate within existing sanctuaries by inhibiting the dispersal of those young animals that SHOULD be ‘lost’ to emigration every year.
The fact that Botswana (in my estimation) is now 3 200 percent overstocked with elephants, means that there is a huge dispersal of young animals into adjacent countries. They are all looking for new habitats in which to set down their roots. These animals are NOT ‘migrating’. They are ‘emigrating’. Some are just exploring. They are ALL seeking a new place to which they CAN emigrate and so to there set up permanent residence like their parents did before them. And behind them they leave their parental families and their family population, intact and resident. It is from THIS resident cohort of the adult population that the Safari Hunting Outfitters must find their quota of trophy bull elephants.
The outfitters’ problem, once all the foregoing is understood, now becomes a little more obvious. The trophy bulls that they seek come from the older age-class of animals – the fifty, sixty and seventy-years olds. These are all bulls that are completely sedentary. They all have permanent home ranges that, though extensive, never change. Furthermore, the older they get the smaller do their home ranges become.
Within each and every safari hunting concession in Botswana, therefore, there is a finite number of good trophy-quality bulls. They ALL have permanent home ranges either wholly within, or partly within, the hunting concession boundaries. When one of these big bulls is ‘taken’ by a hunter-client it is replaced by a much younger animal – an animal that might need another 20 or 30 years to attain quality ivory. Thus are the safari hunting outfitters in Botswana – through no fault of their own - ‘mining’ their quality trophy elephants. All around their hunting concessions - within the ‘fully protected areas’ (the national parks) - there may be a super-abundance of big bulls with huge tusks. But these elephants will NOT move into the hunting concessions because it is these OLD bulls that are THE MOST sedentary of them all.