/ 29 September 2022

Study finds no evidence dehorning rhinos has an impact on the species

Dehornrhino
A study conducted by the University of Bristol Veterinary School in the UK, the Namibian Ministry of Environment, Forestry and Tourism and the Save the Rhino Trust found no evidence dehorning black rhinos has a negative impact on them.

A study conducted by the University of Bristol Veterinary  School in the UK, the Namibian Ministry of Environment, Forestry and Tourism and the Save the Rhino Trust found no evidence dehorning black rhinos has a negative impact on them. 

The study assessed four Namibian sub-populations of black rhino that had undergone different levels of dehorning. Three of the four had been subjected to some level of dehorning at least once. No significant difference was found between dehorned and horned individuals. 

The researchers explored whether dehorning had an effect on a number of factors. These included the age when rhinos give birth to their first calf, the time between the birth of one calf to the next, birth sex ratios, calf survival, causes of death and their life span. 

There was no evidence these factors were affected by dehorning rhinos, which means the practice continues to be one of the best anti-poaching measures for the species, according to the researchers. 

Not ideal but it works

“In an ideal world no one would want to remove arguably one of the most iconic features of a rhino — its horn — but, unfortunately, this is not an ideal world and relentless poaching has forced many reserves to resort to dehorning,” said Lucy Chimes, former MSc student at the University of Bristol Veterinary School and author of the study. 

The black rhino is critically endangered, with only about 6 000 of them left in the world. The animals are poached for their horns, which are made into ceremonial cups and ornaments and crushed into traditional medicines and aphrodisiacs.   

There is a large black market for the horns which go to Asian countries, such as China and Vietnam. 

As a result, many reserves across a number of African countries, including, South Africa, Namibia and Zimbabwe, have resorted to dehorning rhinos as a poaching deterrent. 

Namibia has been at the forefront of dehorning rhinos. It has been using this anti-poaching method since 1989 and many countries have followed suit. 

“To give the population a chance to grow again, we need to relieve the pressure on them by dehorning,” said Pieter Nel, acting head of conservation of North West Parks Board.

However, many are sceptical, saying the sedation for the dehorning process affects them. 

But the study suggests this is not the case. “The balance of the evidence suggests that dehorning has little or no observable impact on population productivity.”

However, the study suggests dehorning might cause rhinos to fear humans, which makes treating them and monitoring difficult, affecting their health.

Not enough data 

More research is needed to find solutions to the problems of dehoring. 

This study was fairly small, with data collected on only 265 rhinos. There aren’t enough studies that show how dehorning rhinos is beneficial. The researchers believe the study is helpful and eye-opening but it has barely scratched the surface. 

“There is still research that needs to be done to support the finding of this report. It would be beneficial to collect as much data as possible to be able to gauge how dehorning helps with anti-poaching and, most importantly, educate more people about this practice.”

The authors of the study note that dehorning is an expensive practice, which is why it is vital to conduct more, larger-scale studies to be able to quantify whether dehorning is effective at deterring poaching and is cost-efficient.

In conclusion, the study found that “the lack of significant results may stem from study limitations such as a small sample size. 

“However, the results are in agreement with several recent studies which also did not find any long-term negative effects of dehorning in black or white rhinos.”

The black rhino has been around for millions of years and there are animals and people who depend on their existence. 

They are good grazers, who shape the African landscape, they are important species for ecosystems, and are a drawcard for ecotourism, which is a source of income for many  communities.

A study conducted by the University of Bristol Vet School, Namibian Ministry of Environment, Forestry and Tourism, and Save the Rhino Trust found no evidence that dehorning black rhinos has a negative impact on them. 

The study assessed four Namibian sub-populations of black rhino which all underwent different levels of dehorning. Three of the four were subjected to some level of dehorning at least once. No significant difference was found between dehorned and horned individuals. 

The researchers explored whether dehorning has an effect on a number of factors. These include the age of when female rhinos give birth to their first calf, the time between the birth of one calf to the next, birth sex ratios, calf survival, cause of death, and lifespan. 

There is no evidence that these factors are affected by dehorning rhinos, which means that the practice of dehorning continues to be one of the best anti-poaching measure for the species, according to the researchers. 

Not ideal but it works

“In an ideal world no one would want to remove arguably one of the most iconic features of a rhino, its horn, but unfortunately this is not an ideal world and relentless poaching has forced many reserves to resort to dehorning”. Lucy Chimes, former MSc student from the University of Bristol Veterinary School and author on the study. 

The black rhino is critically endangered, with around 6 000 of them left in the whole world.  These animals are poached for their horns which are used as ceremonial cups, ornaments and crushed into traditional medicine and aphrodisiacs.   

There is a large market for the black rhino horns on the black market which are distributed to Asian countries such as China and Vietnam. 

As a result, many reserves across a number of African countries including, South Africa, Namibia and Zimbabwe have resorted to dehorning their rhino as a safety measure against poaching. Namibia has been on the forefront of dehorning rhinos; they have been using this anti-poaching method since 1989 and many other countries have followed since then. 

“To give the population a chance to grow again, we need to relieve the pressure on them by dehorning,” Pieter Nel, acting head of conservation of the North West Parks board, said.

However, sceptics are not all sold on the idea of dehorning rhinos as a way of saving them from being poached. They think the sedation process affects them. But the study suggests that this is not the case. The study says “the balance of the evidence suggests that dehorning has little or no observable impact on population productivity.”

The impact of dehorning rhinos should be considered. The study suggests that dehorning rhinos may make them fear humans which will make treating them and monitoring their health very difficult. This will result in their health deteriorating, and this could be fatal. 

This why more research is important on this topic to be able to then find solutions to these deterences. 

Why do rhinos matter? 

The black rhino has been around for millions of years and there are animals and people who depend on their existence. They are good grazers who shape the African landscape and are contributors of ecotourism which is a source of income for some communities. They are important species for ecosystems.

This particular study is fairly small with data collected on only 265 black rhinos. There aren’t enough studies that show how dehorning rhinos is beneficial. The researchers believe that the study is helpful and eye opening but it has barely scratched the surface. “There is still research that needs to be done to support the finding of this report. It would be beneficial to collect as much data as possible to be able to gauge how dehorning helps with anti-poaching and most importantly educate more people about this practice.”

The authors of the study note that dehorning is an expensive practice, which is why it is vital to conduct more studies between and across Namibia and other countries on a larger scale to be able to quantify whether dehorning is effective at deterring poaching and is cost-efficient.

In conclusion the study finds that “the lack of significant results may stem from study limitations such as a small sample size. However, the results are in agreement with several recent studies which also did not find any long-term negative effects of dehorning in black or white rhinos”.

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