Southern Pied-Babbler

BirdSouthern Africa

2 May

Written By Alexander Julius Jensen

Turdoides bicolor

The Sentinel

A lone sentinel perches high above the rest of his companions.

On the ground below, his small family forages for beetles, caterpillars and sun spiders, flipping leaves to find hidden scorpions and burrowing skinks. They preen and play-fight, constantly chattering ("chuck-chuck" and "chow-chow-chow"). Heads down, beaks stuffed or singing, they are ignorant of any potential dangers. With his sharp orange eyes, the sentinel scans the savannah and sky. He sings his own song, a “watchman’s song", which continuously updates his family with news from his surveillance.

Like an apparition materialising from the heat-rippled air, a Gabar goshawk — its grey raptorial body barred white beneath its wings — cuts across the horizon, veering towards the unsuspecting group. The sentinel's song turns to a harsh, repetitive alarm. His family hears his warnings and the fastest flee first, flying to safety in the nearest thicket, as the rest follow right behind. Alone atop his thorny tree, the screaming sentinel is a beacon — his feathers are snowy white and charcoal black against a landscape of ochre and grey. The goshawk's predatory glare, its giant dark eyes, fix upon him. It alters course and careens towards his lookout, chanting a shrill chorus (“teeui-teeui-teeui”) that denotes death.

The sentinel tries to escape. His black-clade wings desperately snatch at the air and lift him from his perch. He flies from his pursuer, but he's a propeller plane fleeing a fighter jet. The grey spectre barrels towards him, reaching out with long red legs armed with curved black talons to stab and skewer him, staining his white feathers crimson. The sentinel dives downwards; he feels the goshawk's talons grasp at his back. He tumbles, and his pursuer tumbles after him. The sentinel fans out his black tail, trying to control his fall, and directs his descent towards a shrub. He scrambles between tight branches, a twisting labyrinth lined with thorns. He feels his flimsy sanctuary shake at the impact of his would-be killer and hears murderous cries of frustration. The sentinel is safe and, thanks to his watch, so is his family.

A Risky Job

Across the savannahs of Africa, sentinels sacrifice their time and safety for the sake of the group. On the ground, mongooses perch atop mounds to scan for danger — none more famous than the meerkat lookouts, who stand ramrod straight to see as far as the horizon stretches.¹ In the trees are the black-and-white watchmen who sing their songs of security, who, like the meerkats, warn their kin — and any eavesdroppers — of approaching threats. These sentinels are the southern pied babblers; the alarm systems of the southern African savannah.

Being a sentinel is a risky job. You separate yourself from the group, losing the safety found in numbers, and, on top of that, you put yourself in a conspicuous and exposed spot. A sentinel babbler is much more likely to be picked off by a predator — an owl or hawk (or goshawk) — than are the foragers below. At the same time, the sentinel forfeits the chance to forage for food and socialise with his group. Why then would any individual put themselves in such a lonely and dangerous position?

Importantly, the lookout is not a lifetime post. Within a group of babblers, the job of sentinel rotates between individuals, so while today's sentinel may forfeit his chance to feed and put himself in some significant danger, tomorrow, when another sentinel stands watch, he'll be foraging with the rest of the family, head down, without worrying about predators — without spending time or effort on being vigilant — and getting the most out of his feeding with the assurance that, if danger appears, the sentinel will warn him. It's sort of like chores when you live with family or roommates. You do the unpleasant job this time, next time it's someone else, and so on, and, as a whole, everyone benefits.

Eavesdroppers & Imposters

A sentinel stands watch for the benefit of its group, its family. But it's hard to conceal a message when that message is meant to be an attention-grabbing alarm. Other birds, like red-billed buffalo-weavers and crimson-breasted shrikes, like to forage alongside pied babblers. Although there's something to be said for safety in numbers, they probably don't just stick around for companionship.

The scimitarbill — a solitary hanger-on, with a long, thin, and de-curved beak — gets the benefit of a watchman without ever having to be one itself. In a way, it is like a parasite, but instead of sucking blood or thieving food, it steals information. The fork-tailed drongo is even more slick. Instead of just mooching off the babbler's alarm system, it becomes a false alarm. The drongo mimics the alarm calls of babblers and other birds, varying its song each time to remain unpredictable, and every time its neighbours retreat in a panic, the drongo swoops in to steal their abandoned meals.

Teachers & Pupils

Southern pied-babblers form tight-knit family groups. The dominant pair are exceptionally devoted to one another; not just socially monogamous, but sexually so, with 95% of chicks belonging to the couple. This is a laudable level of fidelity among birds, most of whom like to sneak off for action on the side. So devoted are the pair to having a family that their parental instincts turn sinister when they fail, occasionally leading them to abduct fledglings from other families and raise them as their own. But parents don’t care for their clutches alone. Helpers also do their part in incubation, although the workload isn’t always spread evenly, and this inequality only becomes more pronounced on hot days — the babblers essentially become lazy. But the eggs are sat by someone until they hatch and, whether begotten or "adopted", as young babblers grow up, they must undergo an education.

The lessons begin from birth. As a chick sits in its nest, downy and helpless and begging for food, an adult hands it its meal with a little flutter of wings and a soft "purr" call. Eventually, the chick learns to associate this call with food and, like a dog trainer using a whistle, the babbler teacher takes advantage of the chick's conditioning. Pied babblers aren't ones to let their chicks lounge around in the nest when it's past time they moved out. The teacher will come to the chick one day, "purring" and holding food in its beak, but as the chick reaches for it, the teacher backs away, forcing the chick to leave the nest in order to get its meal. The babbler chick is essentially baited into fledging.

The teaching doesn't end there. Adults will use the "purr" call like a school bell, summoning their students to foraging sites. By accompanying the adults, the students learn where to search for food — not by memorising the location of sites, which change over the course of the year, but by recognising the characteristics that make an area good for foraging and signs that indicate a predator's presence. All of the adults in the group act as teachers, although some are better teachers than others (better at finding or capturing food), and they garner the most pupils.

The babblers' sentinel neighbours on the savannah, the meerkats, also teach their young. An older meerkat places its pupil in situations it will encounter as an adult. As an example, a meerkat pup will first be presented with a dead scorpion, then an injured one with its stinger removed, and finally a healthy one for it to kill all on its own. But if a meerkat teacher is a boxing coach who instructs from the sidelines, a babbler is throwing punches in the ring. While meerkats expose their young to different experiences, babblers actively show them how it's done, coaching them in just the right ways to be a successful adult, a successful forager, and a successful sentinel.

A Babble of Babbler

Animal names sometimes seem like a bunch of babble. Closely related species — that is, those that have recently shared a common ancestor — often also share the same name. All the species in the family Columbidae are either pigeons or doves; the members of Podicipedidae are all called grebes; and Alcedinidae are kingfishers.

It's nice when this is the case, for simplicity's sake. But so rarely is it so. Actually, even the latter example, the family Alcedinidae, aren't all known as kingfishers. There are over 100 species in the family, the vast majority of which we do call kingfishers, but then there are five species of kookaburras thrown into the mix, which are still kingfishers, despite not being named so. But, compared to other bird families, the kingfishers are far from complex.

The family Picidae is made up of woodpeckers, flickers, sapsuckers, and wrynecks. The family Accipitridae is made up of hawks, eagles, kites, harriers, and vultures. The family Tyrannidae is made up of flycatchers, kingbirds, phoebes, elaenias, tyrannulets, etc.

A Eurasian blackbird (*Turdus merula*) on the left and a red-winged blackbird (*Agelaius phoeniceus*) on the right.

A common quail (*Coturnix coturnix*) on the left and California quail (*Callipepla californica*) on the right.

A Eurasian magpie (*Pica pica*) on the left and Australian magpie (*Gymnorhina tibicen*) on the right.

Left to right: a European robin (*Erithacus rubecula*), American robin (*Turdus migratorius*), and pink robin (*Petroica rodinogaster*).

The confusion also goes the other way.
There is a blackbird from Europe and one from America, Old World and New World quails, a Eurasian magpie and an Australian magpie, a European robin, an American robin, and a family of Australasian robins — none of which are close relatives despite sharing the same names. Animals, especially birds, that aren't closely related at all, are given the same name because of their superficially similar appearances. A fitting case study are the babblers.

Left to right: a Taiwan scimitar-babbler (*Pomatorhinus musicus*), puff-throated babbler (*Pellorneum ruficeps*), white-browed shrike-babbler (*Pteruthius aeralatus*), spotted jewel-babbler (*Ptilorrhoa leucosticta*), and jungle babbler (*Argya striata*).

The so-called babblers are split into five different families. There are the Old World babblers in the family Timaliidae, the ground-babblers in Pellorneidae, shrike-babblers in Vireonidae (alongside the vireos), jewel-babblers in Cinclosomatidae (with the quail-thrushes), and several species, including the southern pied-babbler in the family Leiothrichidae (along with laughingthrushes, sibias, fulvettas, chatterers, and more.)

The lesson is, common names are not to be trusted. There is a giant otter shrew that's related to neither otters or shrews. A moonrat that isn't a rat, nor even a rodent. A Guinea pig that is a rodent (not a pig), but that doesn't come from Guinea. As well as slowworms which are actually legless lizards.

If one wants a view of the wider tree of life — of the true relationships between a shrike-babbler, ground-babbler, jewel-babbler, et cetera — they'll have to dive into the world of taxonomy; into the nested groupings of phyla, classes, orders, families, genera and the species therein. That's not to say taxonomy is easier to parse, just that it has stricter rules about which animal is which, what it's called, and who it's related to. Taxonomy, as bloated and unintuitive as it may seem, is the best method we have to put the living world into some kind of order. It's the system which cuts through all the babble.

¹ Meerkats are mongooses. Other mongoose species — yellow, banded, and dwarf mongooses — also live in tight social groups and rely on sentinels to watch for danger. Common dwarf mongooses even team up with hornbills to optimally avoid predators. You can read more about this unlikely partnership here!

**Where Does It Live?**

⛰️ Semi-arid to arid savannah.
📍 Southern Africa; Botswana, Namibia, South Africa, and Zimbabwe.

‘Least Concern’ as of 12 June, 2024.

IUCN

Size // Small
Length // 24 - 25 cm (9.8 in)
Weight // 63 - 96 g (2.2 - 3.4 oz)
Activity: Diurnal ☀️
Lifestyle: Group 👥
Lifespan: Over 10 years
Diet: Carnivore (Insectivore)
Favorite Food: Insects 🦗
Class: Aves
Order: Passeriformes
Family: Leiothrichidae
Genus: Turdoides
Species: T. bicolor

A sentinel babbler is more likely to be targeted by a predator, but the sentinel today will benefit when another babbler in his group takes over the job tomorrow. The babblers foraging on the ground don't have to waste time or energy on being alert.
Some hangers-on, like scimitarbills, take advantage of the babbler's alarm system by foraging nearby. While fork-tailed drongos produce babbler false alarms — varying their calls each time to remain unpredictable — then swooping in to steal the abandoned meals.
Southern pied-babblers form tight-knit family groups. The dominant pair are exceptionally devoted to one another — not just socially monogamous, but sexually so, with 95% of chicks belonging to the couple (a rare level of fidelity in the bird world).
If a southern pied-babbler couple fail to have offspring, they're known to abduct fledglings from other families and raise them as their own.
Helper birds assist parents in incubating their eggs, although the labour isn't always distributed equally, and the inequity becomes more pronounced on hot days — with the babbler essentially becoming lazy in the heat.
From birth, pied-babbler chicks are taught to associate an adult's "purr" call with receiving food (like a dog trainer using a whistle and treats). One day, the adult comes to the nest, "purring" and holding food, but doesn't approach, forcing the chick to leave the nest to receive its meal — essentially baiting the chick into fledging (leaving the nest).
Adults will keep teaching chicks by calling them to foraging sites — not to memorise the locations, which change over the course of the year, but to recognise what makes a good place to forage.
All of the adults in a babbler group act as teachers, although some are better teachers than others (better at finding or capturing food), and they garner the most pupils.