Today, the 14th of April, is World Dolphin Day. This is a day dedicated to the hugely intelligent and wonderfully inquisitive cetaceans that roam our oceans and rivers. Also known as the pink river dolphin, or boto, the Amazon river dolphin (Inia geoffrensis) is a freshwater dolphin that inhabits the waterways of the Amazon and Orinoco rivers of South America.
The largest river dolphin species in the world, these marine mammals can reach 2.5m in length and weigh over 180kg in males. They are often called pink river dolphins as the adults develop a pinkish tint, thought to be caused by repeated abrasion of the skin surface. Males tend to be pinker than females because they are involved in more intra-species conflict.
Strictly carnivorous, the Amazon river dolphin feeds on a plethora of aquatic animals; they are known to consume up to 53 species of fish – one of the widest ranging diets among all toothed cetaceans! Common menu items include catfish, piranhas, river turtles and freshwater crabs.
The aim of World Dolphin Day is to ultimately raise awareness for these species and the threats they face. For pink river dolphins, their only threat is us. Fishermen see them as pests, and may hunt them to reduce the competition for fish. Moreover, these dolphins can easily get tangled up in fishing nets or suffer wounds colliding with boats. The petroleum industry is also a major threat – oil leaks cause irreparable damage to the fragile aquatic ecosystems in which these dolphins live.
Amazon river dolphins were once seen as magical creatures by traditional Amazonian people, believing they had special powers. For this reason, they were spared from mankind’s destructive hands. However, now we seem to have forgotten the phenomenal majesty of these dolphins, subsequently they are listed as endangered. Humans need to re-establish the humble connection we once had with our wildlife.
A couple of days ago, Netflix released a stunning new series called ‘Our Planet‘. It is a nature documentary series hosted by Sir David Attenborough that aims to explore earth’s extraordinary species and wildlife spectacles. However, this 8-part series also highlights how our planet’s beauty could disappear if we do not act soon. The devastating consequences of climate change are being seen across the entire world; from the frozen poles to the deepest of seas.
I recently finished watching the second episode of Our Planet titled Frozen Worlds. The final few minutes of the episode focused on a massive herd of Pacific walruses on the north-eastern coast of Russia. It is the largest gathering of walruses in the world – secluded to a small island as the sea ice they usually live upon has retreated further north. One scene showed how hundreds of walruses on cliff faces plummet to their death as they desperately try to return to the sea. It was a harrowing but necessary scene. In this post I want to share the wonder of the walrus and the threats this tusked mammal faces. I want to share how we can help and hopefully avoid further tragedies in the future.
Native to the frozen waters of the Arctic, the walrus (Odobenus rosmarus) is an enormous tusked seal. They have a huge, blubbery body, long ivory tusks, and a moustache of sensitive whiskers for detecting food. The males can be twice the size of the females, weighing over a tonne, but both sexes posses tusks. Walruses are highly sociable, gathering in herds of thousands of individuals on beaches and ice floes.
Walruses are not particularly deep divers but they can remain submerged for up to 30 minutes. They have a diverse and varied diet. Their menu is predominantly made up of clams and other bivalve molluscs. However, they will readily eat shrimp, crabs, sea cucumbers, corals, tube worms and even parts of other pinnipeds (seals). Due to their size, they only really have two natural predators – orcas and polar bears.
There are three subspecies of walrus. These are (in order of increasing population) the Laptev Sea walrus (O. r. laptevi), the Atlantic walrus (O. r. rosmarus) and the Pacific walrus (O. r. divergens). I’m sure you can guess where all three are found. The Pacific walrus is the largest subspecies of walrus and one of the largest of all seals – exceeded in size by only the elephant seal.
Arguably, the most intriguing aspect of the walrus is their 1m long elongated canines – their tusks. These seemingly redundant teeth are actually a great evolutionary adaptation to their Arctic habitat. They serve a variety of uses including helping them to haul themselves out of water, break breathing holes into ice from below and win battles against rivalling males (bulls) to retain control of their females (cows).
Aside from their ivory tusks, walruses have many other adaptations making them perfectly suited to a life on the ice. For one, they have a tremendously thick layer of blubber to keep them warm in the freezing Arctic waters. Moreover, they will use their sensitive whiskers to scan the sea floor, foraging for a suitable meal. Their streamlined body and paddle-like front flippers allow them to breeze through the ocean with ease (the same cannot be said for on land).
The IUCN (International Union for the Conservation of Nature) lists the walrus as ‘vulnerable’. In the 18th and 19th century the main threat for the walrus was American and European sealers and whalers who hunted the Atlantic population to almost extinction. Although hunting of walruses is still a threat to the species, the rate of killing has significantly slowed down; only certain Indigenous groups such as the Inuit are permitted to hunt them at a sustainable rate. To these communities, they provide a significant supply of meat for nutrition, tusks and bones for tools, oil for warmth, and tough hide for rope and building coverings. Global trade in walrus ivory is strictly prohibited by CITES (Convention on International Trade in Endangered Species).
Presently, the main threat to the walrus is climate change. Our planet is changing at an unprecedented rate. Our planet’s species cannot possibly keep up. As the Arctic ice retreats further and further towards the poles, walruses have fewer resting grounds to breed. This is forcing them to congregate on crowded beaches, resulting in hundreds of stampeding deaths.
Paradoxically, the walrus’ superb adaptations to Arctic life have been their downfall. As our unsustainable rate of destructive development causes greenhouse gas emissions to rise, our planet warms. Coral reefs dwindle and die. Weather conditions intensify. Migration patterns are altered. Ice melts. The effects of climate change are real and they are here.
We must stay hopeful and determined though. One person can still make a difference. By reducing our energy consumption, using greener means of transport, eating a more sustainable diet, investing in renewable sources of energy, urging governments to help and telling the world, we can help combat climate change. The shocking walrus scene on Our Planet was not enjoyable to watch, but it was vital. It inspired me to write this post and gave me an extra push to make a difference.
Named for its crown of stiff golden feathers, the grey crowned crane (Balearica regulorum) rules over the savannahs of Southern and Eastern Africa. They may also be found in wetter habitats such as marshes and around lakes. Although its plumage is mainly grey, it exhibits shades of white, gold, red and black. They reach around 1 metre in height and even wander around like royalty – with their entire body postured upright.
African crowned cranes (which includes the closely related black crowned crane) are the only cranes that can grip branches, enabling them to roost up in trees. Grey crowned cranes have a spectacular breeding display. Jumping, dancing and bowing are just some of the tactics used to attract a mate. They also deploy a booming call by inflating their red gular sac (the bit of red skin beneath their chin). Once they have successfully mated and created their nest, grey crowned cranes will lay a clutch 2-5 eggs.
Omnivorous, these birds have a varied diet. Examples include grasses, seeds, insects, frogs, snakes, worms and small fish. They have adopted an effective hunting mechanism, stamping their feet as they walk to flush out insects and other invertebrates. A similar strategy is used when they follow larger grazing herbivores such as antelopes and rhinos, except they don’t have to do any work. They simply follow these mammals and swiftly devour any small creatures turned up by the passing grazer. This is an example of commensalism. Commensalism is a form of symbiosis (a biological interaction between two organisms) in which one organisms benefits whilst the other is unaffected. In this case, the grey crowned crane benefits and the grazing mammal is unaffected.
Sadly, these royal birds are endangered. Grey crowned cranes face a plethora of ongoing threats. Drainage of the natural wetlands in their habitat is leaving them with fewer places to nest. Overgrazing by livestock is limiting their availability of food. Pesticide pollution is interfering with the delicate ecological balance of Africa. Live capture and egg collection for commercial trade is also a detrimental threat to these cranes. However, organisations such as the International Crane Foundation are helping to conserve this species. By improving and enforcing harsher policies that strengthen the consequences of the illegal wildlife trade, they hope to reduce the atrocity of this trade. Moreover, they are encouraging methods to minimise the conflict between grey crowned cranes and traditional farmers.
One of the things I can do is to spread a wider awareness for the status of these cranes and the threats they face. As the national animal of Uganda, the grey crowned crane even appears on the country’s flag. They are unique in both appearance and behaviour and play a great ecological role. Their reign is not yet over.
Antelopes are some of my favourite animals to write about. Seemingly mundane to some, I just love the elegance and majesty of these hoofed mammals. When I picture an African sunrise, I see antelopes like impala and topi wandering across the amber horizon, just carrying out normal day-to-day activities. I think that it’s the simplicity and freedom of antelopes that draws me towards them.
Topi (Damaliscus lunatus jimela) are no exception to this. A subspecies of the common tsessebe, topi may not look like the most glamorous ungulate (hoofed mammal) but they are certainly dignified and graceful. They inhabit the savannas and floodplains of East and Central Africa, where they graze on the freshest grass they can find.
Uniquely patterned, the topi has a reddish-brown coat with patches of glossy black on their upper legs and face. They also have two ringed horns which curve backwards. Topi are surprisingly territorial, including both males and females. Males will often stand on termite mounds to assert their dominance over their territory and look out for predators. Females will also help to defend their territory from any potential threats. Fights can often break out between individuals as they compete for breeding rights.
It is thought that topi have one of the most diverse social organisations of all the antelopes. Females only come into estrus (a point of the reproductive cycle whereby females are ready to mate) for only one day every year, so mating season can get very intense. Both females and males will compete with each other to ensure their genes are passed on to the next generation. Envious females may even aggressively disrupt copulations – eventually chaos ensues.
Topi are built for speed. Their streamlined shape and lean build allows them to rapidly evade predators such as lions, leopards, cheetahs, spotted hyenas and painted wolves. Their acute hearing and keen eyesight also gives them an advantage over predators.
Topi have quite a long gestation period (8 months) in which they give birth to a single calf. As with other antelope species, newborns have an incredible ability, they are able to wonder around and follow their mother immediately after birth. Calves are lighter in colouration, allowing them to perfectly blend in with their dry and arid savanna habitat. Topi are currently listed as ‘vulnerable’ by the IUCN (International Union for the Conservation of Nature) since their future, like thousands of other extant species on earth, remains uncertain.
Furry but fierce, the slow lorisis the world’s only venomous genus of primate. Their genus (Nycticebus) consists of several species, all of which live in South East Asia. Aptly named, this arboreal mammal moves slowly through the tropical forests of S.E. Asia. Their nocturnal lifestyle helps them to avoid competing with other diurnal primates that share their habitat, as well as staying hidden in the darkness.
The slow loris is a master of stealth. When ambling through the dense foliage, they make little to no noise. If spotted, they will freeze, remaining motionless until the threat is gone. Their natural predators include snakes, hawk-eagles and, shockingly, even orangutans. Therefore, slow lorises must stay sharp and furtive.
Omnivores, slow lorises mainly feed on insects, fruits and tree-sap. They have a few adaptations to ease the process of feeding. Firstly, they have a long, narrow tongue – one of the longest of all primates – to reach tree-sap stashed in cracks and crevices. Their hands and feet have a firm and wide grip, allowing them to maintain balance and lunge forward to capture a meal. This grip also enables them to eat using both hands whilst hanging upside down from a branch.
Arguably the most fascinating aspect of the slow loris is their venom. The toxin is obtained from their brachial gland (a gland found on their upper arm). A slow loris will lick this gland, activating the secretion of the toxin. When mixed with saliva, this venom can cause painful swelling and near fatal anaphylactic shock in humans – though incidents are very rare. The toxin is used as a deterrent to predators, however parents will also apply the toxin to their infants’ fur as a means of protection. It is thought the venom is obtained from the variety of distasteful and toxic insects that make up the slow loris’ diet.
The slow loris has a large cultural significance. Thought to be the gatekeepers to the heavens, they are often used in traditional medicine to ‘ward off evil’. Unfortunately, this is causing a decline in the population of slow lorises. Another major threat is the wildlife trade – they are often captured and kept as exotic pets. People sharing pictures and videos of these ‘exotic pets’ continues to fuel a vicious circle, so please don’t like or share any viral videos of these animals circulating online. Along with habitat loss, these threats are endangering the survival of slow lorises. Reducing the demand for slow lorises on the wildlife trade is the best way to stop the constant exploitation of these uniquely stealthy creatures.