With the monarchy so in the news as of late, it seemed an appropriate time to celebrate and shed light on the monarchies of the animal kingdom. No one can be sure why animals form the vast range of social structures that they do. Why does a leopard live alone but a lion in a pride? Why are some bees’ solitary and others live in strict social structures? We can make smart guesses based on food and habitat availability and population sizes, but how the monarchies of the animal kingdom evolved is truly a mystery and marvel. Here in Botswana’s Okavango Delta, there are four such monarchies I’ll be shedding light on today. If you’re curious then, please do, read on!
The first mention has to go to the southern ground hornbill. Known as Ingududu in isiZulu, Mahutuhutu in Sepedi, Lehututu in Setswana, and colloquially as the boom-boom bird, there is no better way to describe the other-worldly sound produced by these prehistoric beauties. Waking up to the sound of their unique cries, which can be heard several kilometres away, is a quintessentially African experience. Their other nickname, the ‘thunderbird’, is thanks to the traditional belief that they can protect against lightning spells and rain during drought.
Groups of southern ground hornbills can often be seen sauntering around on the ground, in numbers ranging from two to eleven. This group is made up of a monogamous dominant pair and, usually, their non-breeding sons. These two claim exclusive rights to breeding, while the rest of the group must defend their territory, plus feed and rear their monarch’s chicks. Even with all hands (or claws?) on deck, success isn’t guaranteed. Of the 3-eggs laid, just one chick survives in a brutal battle of the fittest. Of those, it’s estimated that only one chick will fledge every 6-years per group, but those lucky few that do may may live up to a whopping 40-50 years old in the wild. This unique behaviour makes these birds the largest known cooperative breeding bird species in the world.
Next, we move to wild dogs. You might know these fantastic hounds by a different name, from cape hunting dogs, to the direct translation of their scientific name (Lycaon pictus), meaning ‘painted wolf’. True to this name, African wild dogs are famous for their mottled coats, each as unique as a fingerprint. They've also got themselves something of a reputation when it comes to hunting, so much so that the San hunters of Botswana would traditionally smear the wild dog’s blood on the soles of their feet, believing that in doing so their own hunts would be rewarded with such success. Working together as a pack, African wild dogs have a success rate of killing their identified targets of nearly 80% – one of the highest of all mammalian predators.
Like the thunderbird, breeding is restricted to the alpha male and female, and their pups are the first to the table at the hunts that everyone else worked so hard for, even if they didn't participate themselves! Even the sick and elderly are given places of priority at the dinner table. African Wild Dogs will care for ill, injured and elderly pack members, no matter if they are holding the pack back. But, should a beta breed, the alpha will be forced to decide whether to adopt or kill her subordinate’s offspring, or banish her to raise the pups alone. Raising an average litter of 10 pups, the highest of any canid, requires all paws on deck. They divvy up tasks, including babysitting, den-cleaning, and hunting, but all take a role in bringing back some regurgitated meat for the pups and pup-sitters, all for the sake of their monarchs.
One of the first things you’ll notice when visiting the Delta are the colossal termite-mound-spires that dot your surroundings. In this otherwise flat landscape, these mounds are coveted lookout points for sharp-eyed residents or convenient burrows for them to protect their young. But the termite mounds are so much more important than that. Indeed, we can thank their tiny architects for the very existence of the 150,000 islands that pepper this vast inland oasis today. From improving habitat diversity, to enriching the soil, and disposing of toxic salts that could quickly overwhelm the Delta, termites and their fungal friends are true ecosystem engineers in a symbiosis that is the oldest evidence of agriculture here on Earth.
As the first rains drops hit the parched Kalahari ground, millions of winged alates (the lucky few termites in a colony that are born to be sexually mature) emerge for an all-or-nothing nuptial flight. In a classic tale of romance, if a female from one colony meets a male from another, they chop off their wings and get down to business. Otherwise, they die. She is the queen of her new colony, and the male, her king. Their dynasty gives rise to an army of sterile workers, split into a caste system with highly specified jobs, including workers, soldiers, and the lucky few who get to move out and reproduce. All toil night and day to provide for the colony, farming their fungal friends. Nestled in a protective capsule in the heart of the mound, the royalty’s sole purpose from then on is to mate. The Queen will lay one egg every three seconds for up to 15-years. Over time, this taxing process causes her to distend, transforming into a white, swollen grub the size of a human index finger. In this way she can live until 60-years old: the most ancient of all grubs.
The Damaraland mole rat is a burrowing rodent found here in Botswana's Okavango Delta. Luckily for them, they haven't quite inherited the appearance of their naked mole rat cousins, but they do share some similarities. Damaraland mole rats are eusocial, meaning that only a single breeding pair within a colony (which can number up to 40 individuals) is capable of reproduction. To help them is an army of non-reproductive individuals including females with small, underdeveloped uteri and tiny ovaries, and males with small testes that produce no viable sperm. As long as the breeding female lives, so too do her subjects in this form. If she is removed, however, then the other females develop fully but their male relatives do not, a neat trick to avoid inbreeding within the colony.
These cooperative groups share a sleeping nest and burrow system, living in a relatively peaceful existence until it comes to warding off newcomers, who meet their sharp teeth and savage bites! Working together, they care for the young and build an extensive network of burrows. As a team, they are more likely to find the juicy tubers that they exclusively rely on for food and water outside of the rainy season, then they would be if they were to go alone. With a queen to produce a constant stream of extra helpers, individuals give up their personal right to reproduce for the sake of survival and indirect reproduction via their relative. The adult males are the primary dispersers, but above ground they are extremely vulnerable to predation.
The astonishing monarchies of the odd animals mentioned in this blog have arisen out of necessity. It takes many hands, claws, or paws to raise a brood of demanding young, especially in the treacherous paradise that is Botswana’s Okavango Delta. Today, we are pushing these animals to the edges of their extremes. The low reproduction which necessitated their monarchies leave them extremely vulnerable to extinction, with wild dogs, Damaraland mole rats, and southern ground hornbills already on the brink. It has never been more important that we protect wild spaces and do what we can to limit environmental change for their inhabitants. If you've enjoyed this blog, then please take a moment to think about what you can do to help. Every little truly makes a difference.