Why are elephants considered ecosystem engineers?

The concern regarding the plummeting elephant population is not misplaced. Elephants are well known for generating millions of dollars of revenue in the form of wildlife tourism, but they are also ecological curators. Some examples of their ecological curation are seed dispersal, habitat modification and symbolic relations with other species. Without the world’s largest terrestrial mammal, ecosystems across Asia and Africa would collapse, so it is no surprise that conservationists are racing against time to conserve these ecosystem engineers.

Elephants are considered ecosystem engineers

Role of Elephants in Seed Dispersal

Extensive seed dispersal is perhaps the most prominent ecosystem service provided by elephants. On a daily basis, elephants consume over 180kg of foliage. However, only 45% is actually digested with the remainder being released as dung. An individual elephant can produce up to 100kg of dung. Given the prevalence of fruits in their diets, elephant dung contains a sizable number of seeds. Studies found that, through their dung, a single African Forest Elephant disperses 346 seeds per square kilometre in a day. Their Savannah counterparts are even more impressive, dispersing over 2,000 seeds per square kilometre.  No wonder elephants are considered ecosystem engineers.

The consumption of seeds by elephants is known to increase the germination rates of seeds. A study in Kibale National Park in Uganda found that 57% of Balanites Wilsoniana seeds germinate after being consumed by elephants, whereas only 3% of seeds dispersed below their parent tree germinate. This can be attributed to the gastric acid found in the elephant gut, which scarifies seeds and encourages germination. Elephant dung is also highly nutritious and comprises of high quantities of water, which further enhances the survival and success of seedlings

In addition, pachyderms have the most diverse diet amongst mammals. Some populations in central Africa are known to consume more than 500 species of flora. With a herd travelling anywhere between 10 and 100 kilometre in a day, the gentle giants are at the forefront of the battle against deforestation.

Elephant Dung

Other than seed dispersal, elephant dung has innumerable benefits. Insects, such as millipedes, termites, scorpions, feed on dung. Meanwhile, the popular Dung Beetle regularly lays eggs in elephant dung before burying it underground. While dung is certainly nutritious for offspring, the burying process also allows the nutrients of elephant dung to be transferred to the soil. In a literal sense, elephant dung is a natural fertilizer which facilitates the growth of newer plants. It is not surprising, therefore, that elephant dung is increasing in popularity as a natural agricultural fertilizer, particularly in South India. Furthermore, while elephant dung is nutritious for beetle offspring, it does not protect from depredation by Honey Badges, Francolins and Mongoose. The usage of elephant dung is not limited to the ecosystem. Humans have numerous usages of elephant excretion, including the production of paper, coffee, beer and mosquito repellent.  Ecosystem engineers indeed!

The Role of Elephants in Habitat Maintenance

Beyond afforestation, elephants play a crucial role in habitat maintenance. As they are large mammals, elephant movement often creates clearings through dense forests. These form important passages for a plethora of other species. This is easily observable in Manas National Park where elephants often aid in the clearing of the forest canopy, which increases the light reaching the forest floor. This promotes the growth of ground dwelling flora, hence increasing species richness.

Elephants also help in restricting forest fires, particularly in forest edges. Grazing and trampling decreases fuel load and creates firelines. This prevents the spread of fires from the fire dependent savannahs to the fire sensitive forests of Africa.

Elephants also aid in mitigating climate change by removing smaller trees in forests. This encourages the growth of larger and hard wood trees, which have higher carbon sequestration abilities. In fact, in Central Africa, elephants have been credited for increasing the carbon sink by 3 billion tonnes through this method

Grasslands, which are on the verge of death, also benefit from the presence of elephants. African Savannah Elephants are known to damage 90% of trees taller than 2 metres, compared to a mere 28% by their forest counterparts. This not only maintains, but also expands, open habitats. The expansion of forests in Africa during the Pleistocene and Holocene time frame coincides with a temporary decimation of elephant populations in the region.

Elephants are also responsible for creating microhabitats and ecological niches. This has proven helpful for many species. Extensive browsing by elephants can damage trees, hence creating refuge for numerous arboreal fauna, such as smaller mammals and reptiles. 

Elephants share Symbiotic Relationships

Pachyderms have an innate ability to detect water from underground sources. Upon detection, the giants utilize their tusks to dig waterholes, which supports numerous species during the dry months. In fact, in the Horn of Africa, Olive Baboons have been observed to follow elephant herds during the dry season, whenever they wish to quench their thirst. However, the relationship is not just one-sided. Troops of baboons generally produce a cacophony of alarms in the presence of predators. While elephants are rarely preyed upon, the extra vigilance never hurts.

Elephants share similar relations with insect consuming birds. Like other megaherbivores, such as rhinos and buffalos, elephants are not spared by parasitic insects leaching onto their skin. The high density of insects attract numerous species of birds, such as Oxpeckers. The consumption of insects prevents elephants from developing irritation and other infections

A study in Myanmar published in 2019 by the Wildlife Conservation Society, found that elephants can also help conserve amphibians. During rains, water often collects within elephant tracks where the study found a presence of tadpoles. Large clumps of eggs from various species of frog were also found. As the tracks do not allow for water seepage, the pools of water do not dry up during the summer months. The lack of predators, such as fish, allow tadpoles to complete metamorphosis, and become frogs. The tracks also aid in connecting different frog populations, allowing for increased gene flow. Elephants can truly protect the plummeting population of frogs.

The importance of elephant conservation can never be emphasized enough. Being a keystone species, entire ecosystems rely on elephants. Other species which have displayed such remarkable ecosystem influence include the Gray Wolves in Yellowstone National Park. It is essential that we try to prevent the extinction of our planet’s beloved elephants.

Caring for Ecosystem Engineers

Help us Help Them! Think Wildlife Foundation is a non profit organization with various conservation initiatives. Our most prominent campaign is our Caring for Pari intiative. Pari is a rehabilitated elephant at the Wildlife SoS Hospital. 25% of the profits from our store are donated to the elephant hospital for Pari. Other than buying our wonderful merchandise, you could donate directly to our Caring For Pari fundraiser.

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