THE RHINO SERIES: The future of rhino conservation
In the last instalment of The Rhino Series we looked at the biggest debate in conservation biology today - whether to legalise the trade in rhino horn or not. According to the scientific and academic literature we have two options, either we stay safe with what we know or take a huge risk. We can keep fighting off poachers, supporting rhino population growth and encouraging cultural change in south-east Asia, in the hopes that the trend of reduced poaching cases continues down to zero. Or we can take a major risk and legalise the trade. This will either see rhinos protected and trade networks dismantled. Or, it will inadvertently open up entirely new markets for rhino horn and multiple species will be sped towards extinction.
The consensus currently seems to be in support of maintaining the status quo. However, as current figures suggest that rhinos are struggling to maintain population replacement levels and could quite easily go extinct within our lifetimes, today I’m going to take you on a thought experiment. We’re going to imagine what a world without rhinos might look like. Here, as our usual focus is southern Africa, I’m sticking to white and black rhinos, mostly white because that’s where the majority of the scientific literature has focused its attention. But as all rhinos are herbivores we can roughly consider the ecological effects the same for all rhino species.
Just for a bit of context, the difference between white and black rhinos are many, yet ironically, colour isn’t one of them. One of the big differences is the food they eat. White rhinos are grazers, this means they consume grass. Black rhinos are browsers, this means they consume more woody material like twigs and leaves. This also means that they can be found in different habitats. The loss of either of these species, or any species in fact, has knock on ecosystem level effects. We’ve spoken before about the effect of extirpation of species from habitats and the subsequent knock on effects so let’s dig into this with rhinos.
What would happen to vegetation if we lost rhinos?
White rhinos are known as mega-grazers, they eat a lot of grass! So it seems logical that the loss of these animals from ecosystems could leave a lot more grass around. You might think that this would be beneficial for some of the other smaller herbivores such as zebra and impala, but when species co-exist they often tend to strike a balance in the type and length of grass that they eat to avoid competing, in scientific terms this is called niche occupation. If rhinos were lost then the amount of food accessible for other herbivores may also be lost. This could have serious negative effects for populations of many species, grass would grow uncontrolled and trophic cascades could be triggered.
Black rhinos browse more woody vegetation, so losing them would result in an overgrowth of these type of plants. As there are no other species around which can consume on the same level as rhinos this will leave a lot of vegetation which is perfect kindling.
“RHINOS APPEAR TO BE IRREPLACEABLE ECOSYSTEM ENGINEERS, MAINTAINING LAWNS BY THEIR ‘LAWN-MOWER‘ FEEDING MODE, AN ECOSYSTEM FUNCTION THAT COULD NOT BE REPLACED BY SMALLER GRAZING SPECIES.”
Waldram, Bond & Stock, 2008
What about fire?
When white rhinos graze they inadvertently create perfectly manicured lawns which, due to the fact that they have less fuel, are less susceptible to fire. Now fire is a crucial part of many ecosystems and should not be prevented at all cost. But it has to be controlled. There are many different types of fire but what we don’t want is an overfed and over-fuelled fire due to a lack of grazing and excess vegetation. The effect of these larger fires are not only loss of habitat and resource use, they could also have a much more serious knock of effect. Fires release carbon dioxide, a potent greenhouse gas which contributes to climate change.
seriously, climate change?
Yep, we just recorded a podcast with Olli Hyvärinen about the links between rhino conservation and climate change mitigation. It might sound far fetched, but through limiting fire and changing the way in which grass grows due to grazing pressure, rhinos are making the soil in protected areas a carbon sink - meaning that it takes in more carbon than it gives out. This repeated over and over again could balance out the carbon emissions that our daily lives incur and limit climate change. Utterly mind-blowing.
This indicates that, like vultures, rhinos provide a type of ecosystem service for humans. Surely this is a strong enough argument for their conservation, but just in case you need more evidence there’s not that many species around that can just take the place of rhinos. Most have already gone extinct. Hippos could do somewhat of the work because they act in a similar way of grazing and creating lawns, but they are also dependent on water so their effects will only be found within a certain distance from water.
Its feasible to imagine then, that without the grazing power of white rhinos, we may end up with giant swathes of flammable, inedible, carbon-saturated grass meadows which are no good for anyone and could quite easily have major knock on impacts. With rhinos we have less flammable lawns which provide a source of food for many other herbivores, which are then a source of food for many carnivores. Essentially rhinos are one link in an ecosystem which we cannot afford to lose.
and tourism?
It’s clear that losing rhinos would have quite a distinct ecological effect, but rhinos don’t just have ecological value. They have a significant economic value in the form of tourism. They form a key part of many protected areas which tourists pay to visit. We can’t forget here that rhinos are part of the infamous Big 5. They are a key feature of one of the most successful marketing campaigns in tourism. Its unlikely that tourists will stop coming to an area simply due to the extinction of one or two species, but the fact that these countries let these species disappear (even though the cause of such an extinction may emanate from a different country) could have some sort of repercussion. Tourists are sold on the idea of the Big 5, they watch documentaries showcasing the Big 5 and drive around hoping to see these megafauna. The Big 5 has its issues, but the Big 4 would mark a complete failure on the part of humans.
What can you do?
As with most things at Thatch and Earth I hope you’re starting to see that we aren’t just talking about rhinos here. Sure, they’re the focus of this article, but we can’t look at one species alone because they, just like us, are part of an ecosystem which they both influence and are influenced by. In the case of rhinos they have such a massive influence on their environment that we term them ‘ecosystem engineers’. They go in a category with elephants, wolves and yes, humans. Much like umbrella species, losing these engineers has a disproportionately large effect on the environment. It is for this reason that we want to do everything in our power to conserve rhinos, because by conserving them we may just be conserving entire ecosystems too.
So then what could you, as a visitor to southern Africa, do to help the conservation of rhinos? Well, first off, there are a number of incredible NGOs and NPOs working tirelessly to conserve rhinos and spread the message of rhino conservation. Examples like Save the Rhino are a good start. More directly you can contribute to rhino orphanages who do incredible work to ensure that orphaned rhinos may one day be rehabilitated into the wild. Donations can be made even without visiting southern Africa and will really support active rhino research, protection and conservation.
You can visit areas with rhino populations. Maybe even go on a walking safari to see a rhino on foot and actively use your trip as an opportunity to learn. You can make sure that the lodge you’re staying in supports rhino protection and conservation. Many will have anti-poaching units (APU) who you may never see, but who are carrying out invaluable work behind the scenes to protect rhinos.
One of the best things you can do is to NOT post geo-tagged photos of rhinos on social media. Evidence shows that poachers use social media to identify locations with rhinos to target for their next attack. Your images might be amazing and you may be very keen to share these with friends, but please just be careful of which images you’re posting.
Finally, one of the best things you can do is share this message as far and wide as possible. Together we can bring about a cultural change which is the best way to curb rhino poaching and ensure that rhinos can thrive in the wild with one less threat following them round. Unfortunately, there are still people out there who have no idea that rhino poaching is as bad as it currently is or are apathetic. We are on the brink of losing multiple species which have been on this planet for 50 million years. As the rhinos’ only predator, it is our sole responsibility to ensure their survival.
Interested in learning more, check out these references:
Cromsigt, JPGM & te Beest, M. 2014. Restoration of a megaherbivore: landscape-level impacts of white rhinoceros in Kruger National Park, South Africa. JOURNAL OF ECOLOGY. 102(3). P 566–575. https://doi.org/10.1111/1365-2745.12218-
Waldram, MS, Bond, WJ, & Stock, WD. 2008. Ecological engineering by a mega-grazer: White Rhino impacts on a south African savanna. Ecosystems. 11(1), P 101–112. https://doi.org/10.1007/s10021-007-9109-9
Di Minin, E, et al. 2018. Can poachers locate rhinoceroses using social media data?. Abstract from Savanna Science Network Meeting, Skukuza, Kruger National Park, South Africa.
https://www.smithsonianmag.com/articles/heres-what-might-happen-local-ecosystems-if-all-rhinos-disappear-180949896/