81122E – STUDY FINDS RHINO HORNS SHRINKING
London, 2 Nov (AIM) – Researchers at the University of Cambridge have found that rhinoceros horns have gradually decreased in size in just over a century and concluded that this change is likely in response to intensive hunting.
The academic study, published in the journal “People and Nature”, was carried out by analysing photographs of 80 rhinos between 1886 and 2018. This found that horn length decreased significantly in all five species of rhino: white, black, Indian, Javan and Sumatran.
The study notes that three of the five species (the black rhino, Javan rhino and Sumatran rhino) lie within the top twelve Evolutionarily Distinct and Globally Endangered (EDGE) species and all face conservation challenges as a result of hunting for their horns, as well as habitat loss.
It points out that historically rhinos had been killed by trophy hunters with “increased social status for hunters that kill rhinos with the largest horns”. Nowadays, the massacre of rhino populations is led by poaching due to the astronomically high price of horns on the black market.
The report highlights that “modern poaching of rhinos is driven by high demands for horns, particularly in China and Vietnam, where the horn is used in traditional medicines, as a medium for carvings, and as a financial investment in a valuable material”.
As a result, rhino populations have been decimated or wiped out. The report states that “one estimate suggests that 12,750 black rhinos were killed to provide the 36 tonnes of horn sold in Yemen between 1970 and 1986 alone”. It adds that “in Kenya, there were an estimated 20,000 black rhinos in 1991, but only 631 in 2014”.
The authors postulate that shooting rhinos with the longest horns has increasingly left smaller-horned survivors who in turn have passed on these traits to future generations.
According to one of the lead researchers, Oscar Wilson, “we were really excited that we could find evidence from photographs that rhino horns have become shorter over time”.
However, he lamented that “rhinos evolved their horns for a reason – different species use them in different ways such as helping to grasp food or to defend against predators – so we think that having smaller horns will be detrimental to their survival”.
This is the first time that evolutionary pressure has been identified as playing a role in the shrinking size of rhino horns.
However, last year academics published a study showing that ivory poaching in the Gorongosa National Park during the war of destabilisation in Mozambique led to the decimation of the elephant population following the arrival of Renamo fighters supported by soldiers from apartheid South Africa.
That study found that, as the elephant population recovered following the signing of the Rome General Peace Accords in 1992, a relatively large proportion of females were born tuskless.
In Mozambique, poaching over the last four decades has driven rhinos close to extinction.
However, efforts are underway to increase the population through improved anti-poaching methods and the introduction of new stock into national parks such as Zinave in the southern province of Inhambane.
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(AIM / AIMENG)
