The Tsavo Trust is a wildlife conservation non-profit organisation. We use the resources given to us to pursue the protection of all wildlife that it is within our capability to pursue. However, we do have a very specific, self-appointed aim and that is to ensure that the ‘Big Tusker’ elephant does not go extinct.
The size and weight of its ivory generally defines whether an elephant qualifies as a ‘Big Tusker’. Usually, a ‘Big Tusker’ will be a fully-grown male with tusks that reach the earth. Often, with tusks that size, one can expect each tusk to weigh within the region of 45-50kg.
The ‘Big Tusker’ used to be a fairly common sight on Africa’s plains. However, as a result of their popularity amongst big game hunters and poachers, those with the largest tusks have been hunted nearly to extinction. Some estimates suggest there are less than 40 ‘Big Tusker’ elephant in Africa.
We, here in Tsavo, are privileged to play host to an unusually large amount of them. We monitor the entire elephant population of the Tsavo Conservation Area. The TCA is home to roughly 40% of Kenya’s 36,280 elephant individuals.
Of those elephant that call the Tsavo Conservation Area home, we keep an especially close eye on the ‘Big Tuskers’ and emerging ‘Big Tusker’ animals. There are about 10 ‘Big Tusker’ elephant here in the TCA, and a further 30 or so that look like they could reach the mantel. There are many reasons why we pay such close attentions to these creatures.
One of those reasons is that ‘Big Tusker’ elephant live in a greater, more constant state of threat than all others. Bigger tusks command greater prices on the ivory black market and, what’s more, the largest, best-adorned bulls also tend to be the most aggressive or, perhaps, cocksure when it comes to interacting with humans. These, the most magnificently-endowed of Africa’s elephant need vigilant surveillance if they are not to fall afoul of poaching or conflict with humans.
However, we also protect these creatures for many other reasons. ‘Big Tuskers’ are true icons of the savannah, seeing them attracts tourism which generates much of the revenue that feeds into conservation. More on that here.
Another influential reason behind why we’ve singled these creatures out for special protection is the importance they have to the African elephant’s gene pool. Elephant tusks are used for digging to access hidden water wells and tubers, for stripping bark from trees, and in dominance-establishing conflicts.
Tusks are incredibly useful. They are, what’s more, the result of over 34 million years of evolutionary adaptation. And recent studies suggest that, as a result of poaching, human beings are redefining the African elephant’s evolutionary inheritance. Tusklessness is emerging as an increasingly prevalent trait amongst African elephant.
Poaching for ivory is driving elephant evolution toward tusklessness
Tusklessness occurs naturally in African elephant. However, it is typically a rare genetic legacy. Historically, 2 to 6% of African elephant – nearly all female – never develop tusks. However, conservationists and scientists have been noting a seeming upward surge in this genetic trait.
Across Africa, and especially in Kenya, Tanzania and Uganda, tusklessness rates far exceed the historical records. In Mozambique, however, this increasingly common trait has been closely studied on a small population of elephant in Gorongosa National Park. The findings, published in the journal Science, shed some light on this emerging phenomena.
In Gorgongosa, tusklessness amongst female elephant in a population size of roughly 700 elephant individuals, is 32%. That is an obvious and alarmingly large figure and it’s cause is easily discernible.
The area that is now known as a national park was not recognised as such by the warring factions of civil-war era Mozambique. Between 1977-1992, the area and its elephant were entangled in one of humanity’s bitter and far-reaching conflicts for power. Warring factions of the struggle for power killed many of the area’s elephant in order to finance the war effort. It is thought that around 90 percent of the elephant population that existed in modern Gorgongosa were killed by the conflict’s end.
These elephant were hunted for their financial value, for the hereditary heirlooms that would finance the purchase of guns and bullets. As a result, those that were unadorned with sellable ivory, were left to live. After the conflict, the tuskless survivors passed on their genes to the next generation.
This trend has been seen across Africa, and nearly always in areas that, 25-40 years ago, saw unchecked poaching.
Across the continent, tuskless female elephant passed on this trait to around half of their daughters. What’s more, and is of especial concern to conservationists, only a third of their offspring were male.
Tusklessness as a threat to elephant population security
The suspected genetic mutation which leads to the development of tuskless female elephant has been linked to a pair of genes on the X chromosome. It results in tusklessness amongst females, and this could be argued as a favourable genetic mutation in a world where poaching still exists, but it is fatal to male elephants.
Male elephant embryos with this associated pair of genes do not develop properly in the womb. As a result, about half of the male elephant calves with conceived of a tuskless mother have this abnormality and die in utero.
The present fears are, therefore, that the emergence of this genetic abnormality will deplete elephant herds of males and drastically undermine potential regrowth of elephant populations.