RHINOS IN CRISIS

Yes. Rhinos are environmental engineers whose contributions to the ecosystem are unprecedented and irreplaceable.

By shaping and diversifying their environment, rhinos are paving the way for the existence of countless other species of animals and plants. 

As a keystone species, rhinos are nature's environmental architects. They have a disproportionate and unequalled impact on the ecosystem's structure, health, and function, increasing diversity through grazing and defecation.   

Rhinos maintain savannahs, bushveld, wetlands, plains, and forests. Their biological functions include migration passages for species that cannot survive in dense vegetation, creating essential water sources, and enriching soil by forming mud wallows, which are also essential to their ecology and behaviour. 

Additionally, dung spreads nutrients and enriches soil and middens (communal dung piles) foster complex food chains supporting birds, mammals, and reptiles.

According to a study published in the Journal of Ecology, rhino-inhabited areas have 20 times more grazing lawns and areas with fewer rhinos had 60-80% less short grass cover.  

More recently, a study published in January 2022 found Sumatran rhinos are the only known dispersers of 35% of all megafaunal-fruit genera in their Asian rainforest habitat and the loss of Sumatran rhinos has resulted in the loss of an important seed dispersal mutualist.

Rhinos themselves are hosts to several ectoparasites and endoparasites that live on and in their bodies. Parasites, such as ticks and rhino botflies (Gyrostigma rhinocerontis) provide food for wildlife such as African Oxpecker birds, which have a symbiotic relationship with rhinos. 

Besides illegal wildlife trade, environmental pressures such as climate change, but more significantly, habitat degradation, fragmentation, and destruction, are major factors contributing to rhino population declines.

Habitat loss is the consequence of human activities which negatively impact the environment.  There are three types of habitat loss.  Degradation, fragmentation, and destruction of habitats.

Natural habitats are degraded and compromised by pollution, overuse of natural resources, and the introduction of invasive species. 

A fragmentation of habitat occurs when large expanses of habitat are fragmented or destroyed, resulting in smaller, unconnected, or isolated areas.

The destruction of a habitat creates an environment that is no longer able to support the species that live there naturally. 

Due to human interference, rhinos' geographical range has dramatically declined. Few rhinos now exist outside of national parks, sanctuaries, zoos, and wildlife parks, which provide some protection, but are not immune to environmental factors.

Loss of habitat remains a major threat to rhinos.  A vast swath of their historical range has been completely depleted due to urbanization, agriculture, industry, resource extraction, land, air, water, light and noise pollution, deforestation, water networks, vehicular thoroughfares, and conflict. 

As well as affecting spatial distribution, habitat loss has a wide range of consequences. As a result, habitat quality, shelter, food supplies, and nutrient levels decrease. Habitat loss inhibits migration, restricts normal behaviors and interactions, reduces reproductive ability, and genetic diversity. It increases psychological distress, disease risk and transmission and inbreeding. Habitat loss also causes a reduction in seed dispersal, resulting in loss of biodiversity.  When competition for food and territory increases, rhinos enter human-occupied areas, posing welfare risks to humans and rhinos alike. 

Invasive species, although not readily apparent, also have the capacity to cause native species declines and extinctions.   They cause ecological and economic damage and can cause health risks for humans and rhinos.

Colonization causes plants to reproduce quickly, grow rapidly, absorb light and nutrients and choke native flora, the vital food sources of rhinos, as well as alter the environment.

Among the most common invasive species in Asian rhino habitats is Mimosa diplotricha, a woody poisonous shrub that forms impenetrable thickets. Perennial herb Chromolaena odorata and Micania micrantha also known as climbing hemp vine as well as the intimidating Arenga palm. 

In Africa, invasive species such as Campuloclinium macrocephalum (Pompom weed), Lantana Camara, and Chromolaena odorata also significantly reduce grazing capacity.

These factors add to rhinos' vulnerability and accelerate their extinction.

In addition to contributing to the health of the planet, rhinos (and other big game) are also vital to the rural communities that rely on them for an economic boost and survival.

A key driver of economic development in Africa, for example, is tourism, which is a $39 billion dollar industry. Several countries, including South Africa, Botswana, Kenya, and Tanzania, generate $12 billion in revenue from safaris, which include game drives, walking tours, photographic and eco safaris.  Without these exceptional game interactions, tourism revenue would drop, negatively affecting wildlife conservation and local communities.

In the absence of investment, cultural heritage, community upliftment, education, employment, infrastructure, and conservation initiatives, such as anti-poaching efforts, are threatened, causing conflict and poverty.

Climate change is a long-term shift in temperatures and weather patterns. Despite being geographically restricted, rhino habitat destruction and declining rhino populations directly contribute to climate change, which affects us all.

Rhino habitats are fragile and limited, and prolonged rains can destroy them, forcing rhinos into human settlements.  Flooding can cause sedimentation, erosion, pollution, and disease spread. 

Even in areas where flooding is a part of the natural cycle, such as in Kaziranga National Park, India, unprecedented floods had devastating effects on rhinos. Between 16-20 rhinos, including 8 calves, died in 2016.  Flooding caused the deaths of 17 Indian rhinos in 2019 and 10 rhinos in 2020.

Droughts are a familiar occurrence in Africa. However, in recent years, they have become more frequent and intense. A prolonged drought prevents essential water from returning, preventing mud wallows and vegetation growth, as well as crop spoilage, which increases the possibility of malnutrition, disease, disruption of birth cycles, mass mortalities, and competition between wildlife and humans for scarce resources.

Forests, often called 'the lungs of the planet', stabilise the earth's climate by absorbing carbon dioxide from the atmosphere.  Although grasslands and savannahs have been largely overlooked in favor of forests, their role in absorbing carbon dioxide from the atmosphere is no less vital. 

Current Biology published a study in 2022 that found that large animals, such as rhinos, consume vegetation that could fuel wildfires. Wildfires can release large amounts of carbon dioxide into the atmosphere, but gaps in vegetation caused by grazing can reduce their intensity and likelihood.

As a result of large animals shifting vegetation to expose the ground surface, they increase sunlight reflection on the Earth's surface, helping to mitigate global warming while releasing carbon stored in vegetation quickly back into the soil, enabling the growth of new CO² absorbing plants.

One tonne of carbon will be absorbed each year by 1,000 square metres of grass.   In the absence of rhinos, or other large animals such as elephants, savannahs and grasslands would suffer, increasing atmospheric carbon dioxide levels.