Birds Of Sandy Island: 10. The Robber Starling

THE ROBBER STARLING (Lestornis inexorabilis)

Jabbering and wailing, jinking and subterfuging, the Robber Starling is one of the most characterful, and certainly the most vicious, of the Sandy Island birds. It ranks at the top of the island’s passerine pecking order, and is one of the few reasons other endemic Sandinian birds adapt their calls into alarm calls. It is a large starling, about 10 inches long, and though clearly related it differs sufficiently from the most speciose local genus of starlings, Aplonis, to warrant placement in its own genus. The Robber Starling has a heavy slightly curved bill and a short square-ended tail. The coloration is sombre and funereal: males have very matte black upperparts, with white throat and underparts heavily streaked with the same black except in the middle of the lower belly. Females have the same pattern but brown and buffy-beige instead of black and white. Both sexes have piercing red eyes, as fits their character. Juveniles resemble adult females, but more blendy in color pattern with dark eyes.

The Robber Starling is a classic example of the island large-muscicapoidean niche of a merciless egg-eater, as in the Rodrigues Starling, Galapagos mockingbirds, and Tristan Hermit Thrush. The starlings eat just about any eggs they see and can take; only the Giant Pigeon and Bare-chested Parrot are immune to their plunderings. In the absence of eggs, starlings will scavenge carrion; the young are fed on insects. Though they seem so antisocial, Robber Starlings do not eat each other’s eggs. This means that they are susceptible to parasitism from Giant Fantails, so what appears to be an altruistic adaptation might be improperly thought through; starlings would benefit from eating the fantail eggs that show up in their nests. The starlings do eat fantail eggs, however; woe betide the thrush, woodswallow, or whistler who is unlucky enough to have its nest set upon by first fantails and then starlings! That may be all for the best, though; because starlings generally eat entire clutches, the parent hosts are saved from having to deal with outcompeting parasite chicks. Fantail eggs appear no less tasty to starlings than any other eggs.

Robber Starlings hunt in packs, and are social throughout the year. They nest communally, collaborating to build strange “apartment complexes” of sticks that sometimes bind multiple trees or shrubs together. Each pair in such a complex has its own nest hole, with the entrance on the side. The Robber Starling has many calls, but none are mellow or otherwise pleasant. A metallic jabbering is perhaps the most common, but wails like fingernails on a blackboard (or a scratchy theremin, or maybe a Pine Siskin at 1/10th speed), a drawn-out rasp similar to a distorted, supersized Red-winged Blackbird, and a jumble of syllables not unlike a malfunctioning Furby are also frequently heard. Less often, high-pitched “pitch”, two-syllable “chock-chitch”, and a careening downslur very reminiscent of a car alarm are uttered by Robber Starlings.

In addition to being an egg thief, the Robber Starling exhibits several other behaviors that make it unpopular with other birds - and people! Flocks of starlings will fly very fast in thick brush, bumping aside everything in their way. Starlings will also get uncomfortably close to other birds that are just minding their own business. Their nests take up a lot of space, and are occasionally built over or around other birds’ nests. This generally happens if these other nests have eggs, which the starlings eat before engulfing the nest in their own sticks. “Evil” is a word not frequently associated with birds, but in the case of the Robber Starling, it seems particularly apt.

Birds Of Sandy Island: 9. The Needle-billed White-eye

THE NEEDLE-BILLED WHITE-EYE (Woodfordia aciculata)

Woodfordia or Zosterops? This question immediately comes to mind when the Needle-billed White-eye (the “Pin Grinnell” of the islanders) is considered. If never seen in real life, one might come to the conclusion that a specimen of this species is an artifact, consisting of the head of a Zosterops on the body of a Woodfordia - with perhaps even the bill of a Rukia. It is, however, quite a real bird - standard large white-eye size, with an unusually slender, long, straight bill. The head is olive-drab with a yellower throat and standard “white-eye” rings. This contrasts with the fulvous underparts and rufous upperparts. This bigenerality makes the taxonomy of the Needle-billed White-eye a little problematic. It could be a highly derived Zosterops, but the general consensus is that it is the long-awaited third Woodfordia, extending the genus’ range eastward from Rennell and Nendo. Alternatively, it could be of intergeneric hybrid origin. Not many specimens have been collected.

The Needle-billed White-eye’s habits are largely standard white-eye across the board. Its acicular bill, however, reflects an un-white-eye-ly augmentation of its diet. As well as a gleaner and a berryhunter, the Needle-billed White-eye is also an inveterate flowerpiercer. It can easily puncture the bases of flowers for shameless nectar extraction. Disputes between the wasty white-eyes and the nobly corolla-sucking myzomelas seem to be long-standing feuds. Alas, white-eyes frequently get the upper hand merely due to their larger size.

The Needle-billed White-eye’s song is a short, rich warble with a sinister quality. Sometimes a quavering “oo-wee-wee-oo” is given particularly in disputes with myzomelas. Other calls include short “zet” and metallic “zeeer”, chippering “chutter-chucket”, and occasionally a bee-eater-like whine or a ring-modulated scold.

Birds Of Sandy Island: 8. The Sandy Island Monarch

THE SANDY ISLAND MONARCH (Neolalage terrestris)

As with the Dwarf Du, the discovery of the Sandy Island Monarch provides a companion to a species previously considered alone in its clade. In this case, the species in question is the Buff-bellied Monarch of Vanuatu, which the Sandy Island species now joins in the genus Neolalage. Though clearly related, several aspects of its niche and behavior expand the niche packing and behavioral potential of not only the genus but of Monarchidae in general. The Sandy Island bird is the only terrestrial monarch sensu stricto; only the grallinines or “mudlarks”, now generally considered to have joined the family’s ranks though some still gift them their own family, have a similar lifestyle among the monarchids. Slightly larger than the Buff-bellied, the monarch of Sandy Island has a shorter tail and longer, lark-like legs. The color pattern is similar to its congener, but with the black and white of the head nearly reversed: a black head with white hindcrown and supralorals, and a white breast-band. The lower breast and back are both marked with short brown streaks. These pattern and shape differences make the bird almost resemble more a chat, antbird, or bunting than a monarch. Juveniles are patterned similarly to juvenile Buff-bellieds, while subadults resemble adults but with spotted rather than streaked underparts.

The most unmonarchly feature of the Sandy Island Monarch is its nest. Even the terrestrial grallinines build mud nests in trees; the Sandy Island Monarch is the only monarchid that nests on the ground. Its oven-shaped nest is constructed from leaf midribs, and vaguely resembles that of a water ouzel. Both sexes incubate. It is assumed that if Sandy Island had any mud, the monarchs would use that to build their nests instead.

Sandy Island Monarchs walk on the ground with a lilting, stilting gait, hunting for terrestrial and near-terrestrial insects, and are very rarely met with perching in bushes; they are not seen in trees. The monarchs are sassy birds that rank high in the pecking order: above woodswallows, whistlers, and cuckooshrikes, but below Giant Fantails and Robber Starlings. The song is a distinctive slurred whistle, “peeowit-o-weeowit”, but more frequently the bird utters churring scolds not unlike other monarchs along with a tweezy “zeep”.

Birds Of Sandy Island: 7. The Giant Fantail

THE GIANT FANTAIL (Rhipidura ingens)

This species, like the Great-billed Crake, is an example of evolutionary malleability in a genus that was not believed to be so variable prior to the species’ discovery. As its name implies, the Giant Fantail is by far the largest of all fantails. A foot long, it is proportionally shorter-tailed but just as fat-headed and short-billed as most other fantails; the combination of size and proportion recalls a cuckoo or nightjar. The latter comparison, however far-flung, is accurate; the Giant Fantail’s gape bristles are certainly luxurious, and the species does appear to be crepuscular from time to time. The fantail’s coloration is very variable, with well-defined forms but many intermediate individuals. There is a pied form, black-and-white very similar to a Willie Wagtail but with less white on the belly, and a barred form with the same pied head pattern in dark brown instead of black, the underparts also dark brown heavily barred with buff. A similar form exists with streaked rather than barred underparts, which can also be black and white instead of brown and buff. Yet another form is entirely rufous. All of these forms can also have a white or buff throat, rump, and/or wing bars. The bill and legs are often black, but especially rufous-form birds can have a horn-colored bill. This polymorphism appears to be mostly unrelated to sex, as several combinations of two forms have been observed mating; however, all barred birds observed have proven to be males. Juveniles are generally gray with a faint head pattern and wing bars.

The Giant Fantail approaches the cuckoos, none of which breed on Sandy Island, in both appearance and niche. It has developed a unique system of brood parasitism that is ultimately cuckooish but with several kinks. The plumage polymorphism is an adaptation related to the broad range of host species, compensating for the absence of egg color polymorphism. Females appear to parasitize the host species they resemble the most: pied ones lay in the nests of White-breasted Woodswallows or Long-tailed Trillers, buff-bellied ones choose Melanesian Whistlers, rufous ones Island Thrushes, streaked ones Robber Starlings, and one all-black female was observed around the nest of a Melanesian Cuckooshrike. Fantail chicks dominate by outcompeting, rather than throwing host eggs out of the nest as cuckoos do. A female fantail probably identifies the male of a host pair by his song; she then spies and sneaks by skulking, waiting for him to replace his mate on the eggs. In the middle of his shift, the fantail spells him; they appear to know the host species’ contact calls and fool them thus despite the difference of size. This vocal mimicry of the host extends to the male song, as it does in those charitable parasites, the whydahs. Here, however, it is rather unusually adapted as the song’s quality of mimicry is rather poor. For example, the triller imitation is usually at only half the speed. The whistler impression is an octave lower, frequently with three whiplashed phrases instead of one. As for the thrush, the fantail’s version sounds like a thrush run through a highpass filter and a distortion pedal. The most remarkable quality of the fantail’s song is its double mimicry; as the woodswallow is already a mimic, a fantail will occasionally imitate other birds in a woodswallow’s typical order, but much more sloppily! 

But the fantail is only a sloppy mimic when singing. Not only is it a brood parasite, but it is also an incorrigible kleptoparasite. Like its cousins the drongos, it has a wide variety of alarm-type calls with which to fool other species into dropping the yummy grubs they may have found. Several non-passerine calls are imitated for this purpose, including the “krawk” of the Dwarf Du. It is interesting to note that all the endemic Sandy Island birds essentially lack an alarm call; that “krawk” is mostly used to summon other Dwarf Du. The only bird predator on Sandy Island is the Barn Owl, which eats a lot more lizards than birds on small islands.

Color variations of the Giant Fantail.

Birds Of Sandy Island: 6. The White-backed Myzomela

THE WHITE-BACKED MYZOMELA (Myzomela warburtoni)

Not much seems to differentiate this species, known locally as a “Tree Shank”, from the many Myzomela honeyeaters elsewhere in Melanesia and Australasia in general. It is certainly uniquely colored and patterned, both sexes having a red head with a black loral stripe, a bright white back and rump bordered by black scapular stripes, and black wings and tail. The underpart pattern is also unusual, with the red throat grading to yellow on the chest, separated from white flanks by a broad black band; the central belly to vent are also black. The juveniles, like those of other myzomelas, are much drabber. At first the juvenile plumage was thought to be the adult female, as drab-plumaged individuals are very common, but once nesting was observed the truth was revealed. Adult plumage is not attained until the bird is at least two years old, which identifies an individual’s rank as this species is a cooperative breeder, with immatures helping adults to feed the nestlings. The delayed adult plumage brings to mind the “jackbird”, that protracted juvenile stage of the Tieke from South Island, New Zealand. However, the White-backed Myzomela shares more in common with another callaeoidean, the similarly nectarivorous Hihi; cooperative breeding sounds like a Hihi-esque strategy even though it is not such a thing, due to the Hihi’s protracted juvenile stage. It is possible that a certain true Hihi technique is in fact prevalent in the myzomela of Sandy Island. Warburton was an amateur ornithologist and former missionary; bushwhacking with his crew on Sandy Island, he once abruptly about-faced with his hand covering his eyes. Wrye asked him what disgusted him so, and his response was, “The blessed myzomelas.” Wrye never asked Warburton what he meant, but he had already guessed; the Hihi’s sexual position, generally regarded as unique among birds, may be duplicated by the White-backed Myzomela. More study is needed…

Like other myzomelas, the White-backed is mostly a nectar feeder; it pollinates various shrubs and vines, especially the glasper vine so beloved by the Dwarf Du. Flocks feed together. The nest is a standard songbird-style cup. The myzomela’s calls include a very high-pitched “skeedeek skeedeek skeedeek”, hard “stich” notes like a Hihi, tooth-sucking noises, and a very fast nasal contact call something like “shank-shweenk”.

Birds Of Sandy Island: 5. The Bare-chested Parrot

THE BARE-CHESTED PARROT (Gymnopsittacus sandinensis)

Those who would argue that the Giant Pigeon is not the most unique and bizarre Sandy Island bird are invariably arguing that the title goes to the Bare-chested Parrot. It is certainly one of only two contenders for most unique and bizarre among the parrots, the other being the Kakapo of New Zealand - to which the Bare-chested has some striking similarities. The Bare-chested is a very large parrot, smaller than some macaws but still around 25 inches in length. Though it is believed to be closest related to the lorikeets of the genus Vini, its body shape is most similar to that of an Amazon, with a relatively very short tail. The throat and chest are completely unfeathered and form a large pink patch of bare skin. The plumage is otherwise a typical parrot shade of green, with a red forehead and rump, light blue nape and dark blue vent. The bill is orange and the legs pink. The Bare-chested is the only flightless parrot besides the Kakapo, and certainly the only flightless arboreal parrot. The wings are shorter relative to the body than those of the Kakapo. One physical feature separates the Bare-chested Parrot from all other birds: its feet lack a middle toe. It grips a branch with one toe in front and two behind, though the outer (rear) toe can be swiveled outward like that of a turaco.

The Bare-chested Parrot’s two main idiosyncracies are its symbiosis with the wattle palm and its extreme behavioral sexual dimorphism. Male Bare-chested Parrots may have the smallest territories of all birds when measured in land area. They are each restricted to a single tree, as they are - like fat Giant Pigeons - flightless and walkless. They are not as inconvenienced as the pigeons, for their one method of locomotion is quite agile - branch clambering in typical feet-and-beak parrot fashion. Necessarily, as the wattle palm is their only home, male Bare-chested Parrots are especially intensely symbiotic with the palms. The flowers, buds, fruit, and seeds are their only food; they eat the fruits while they are still attached and only approaching ripeness, before they fall and are gorged on by Giant Pigeons. In one of the most unusual quirks of wattle palm biology, the seeds remain attached to the tree when the fruits fall off. There are enough seeds on one tree that the parrots cannot deplete the resource at any time; the flowers and fruits form behind the old seeds. The male parrots can squirt their droppings a remarkable distance in order to disperse the seeds. The wattle palm, which is named for the thick involucre of fronds at its crown forming a flattened, acacia- (wattle-) like shape, has evolved a built-in nest site for the parrots. The depression at the center of the involucre is a deep pit, large enough to house ten or eleven nests and protected from rain by large overhanging side-fronds. Only the males incubate; as discussed below, this species is the only polyandrous parrot (the same wags who came up with “incubus incubation” call it “polly-androus”). They have no reason to leave the nest, as the fruits are attached near the nest pit where they are easy to reach. For this reason, Robber Starlings never bother them; the parrot’s beak, adapted to cracking the large hard wattle palm seeds, is certainly strong enough to sever a starling’s neck.

The clutch size of the Bare-chested Parrot is always only one egg. The chick is fed on the larva of a beetle-mimic fly, the palm’s pollinator, which infests the overhanging fronds at exactly the time of chick-rearing. Female chicks are more precocial than males, as they have typical walking leg muscles and can walk. (Males’ leg muscles are partially atrophied as a result of their obligatory walklessness.) The females fledge when the fruits fall; these “debutantes” clamber down from the nests and live terrestrially, walking gingerly with a high-heeled gait and eating fallen wattle palm fruit with the flocks of Giant Pigeons. As the pigeons do later, the female parrots sustain themselves on other fruits and seeds once the wattle palm fruits are all devoured, though they occasionally clamber up into the wattle palms to eat buds and flowers with the males. Not long after the fallen fruits are gone, the male parrots begin their courtship. As with the Kakapo, this consists only of a vocalization; the Bare-chested’s “song” is an extremely loud, long, screechy skronk that ascends in pitch followed by a descending series of shorter, softer honks. The entire population of male Bare-chested Parrots essentially forms a small number of permanent leks based on the locations of the wattle palm groves. Each tree is literally a family tree, as its resident male parrots are always grandfathers, fathers, sons, and/or grandsons. As with other polyandrous birds, there is essentially no pair bond; females will mate with several males each year and lay eggs in many trees’ nests, including sometimes multiple nests within a tree.

The exact timeline of the Bare-chested Parrot’s life cycle has not been studied in detail yet, including the age of sexual maturity. It seems that the female’s “debutante” stage extends over several years, but this is not known for certain; the equivalent point in the male’s development appears to be a period of clambering among his palm’s fronds and working up his courtship call, resulting often in comical “sub-skronking”. The nests are obviously used for generations and as such do not need to be “built”, but at the start of the breeding season males begin to replenish them with strips torn from the overhanging fronds’ midribs. It appears that if there are more adult male parrots in a tree than the nest site capacity in the tree’s involucral pit, the older males will stop displaying and breeding to make space for new nesters.

Bare-chested Parrots seem to have a low mortality rate. Their only predator is probably the Barn Owl, which often nests in holes in wattle palm trunks and takes parrot chicks. Like other parrots, Bare-chesteds are frequently idle and playful. Young ones enjoy teasing Rainbow Lorikeets (the island’s only other parrot species) by pulling their tails.

Birds Of Sandy Island: 4. The Great-billed Crake

THE GREAT-BILLED CRAKE (Porzana carcinophaga)

Until the discovery of this species, it was generally assumed that crakes are not, in an evolutionary sense, malleable. The only significant differences between most island crakes and those of mainlands are the island forms’ flightlessness and their unwariness. The Great-billed Crake of Sandy Island is the only crake known thus far to have an obvious physical modification coming from island evolution. Specifically, its bill is proportionally larger and thicker than those of other crakes. It is not truly wedge-shaped like those of the Purple Swamphen and Takahe; instead, it is conical and evenly tapered. This almost toucan-like beak is attached to a large head for a crake; it is not however otherwise a robust bird. The legs are longer and slenderer than those of other island crakes, approaching the proportions of the mysterious Ua Huka Rail. The coloration is similar to Baillon’s Crake, from which it doubtless evolved; the underparts are a warmer shade of gray, and the flank barring is not reduced as in the Laysan Crake. The bill is relatively bright green, with a dark ring around it near the tip. Though its wings are much shorter than in mainland crakes, the Great-billed is not flightless. The nesting of the Great-billed Crake has yet to be studied in detail; it does not seem to differ from other crakes in this regard. Chicks have been seen walking with adults in typical crake fashion.

With its outsized mandibles, the Great-billed Crake covers a very different niche from the Spotless Crake, which is also found on Sandy Island. The Great-billed’s principal prey is the robber crab. A full-grown robber crab is several times the size of a crake, so the crakes generally attack young crabs. Above a certain size of crab, crakes may hunt in packs. As many as 6 or 7 crakes will endeavor to seize a crab’s legs, avoiding the claws, and pull away from each other so that the crab is essentially drawn and quartered. Alternatively, crakes may ride crabs’ backs and attack the interstices between the carapace joints. (The robber crab is really a shelled hermit crab, and its carapace is jointed where a hermit crab’s abdomen is soft.) Robber crabs form only one part of the crakes’ diet. Another important element is bird eggs, which they can easily crack with their outsized bills - even the thick-shelled Giant Pigeon’s. The crakes are the scourge of Dwarf Du during their “bornge”, though not quite as depredaceous as the Robber Starlings. As megapodes’ eggs have especially thin shells, it is an entertaining sight to see the crakes crush Dwarf Du eggs wetly like boba. Due to their breeding in the austral summer, Great-billed Crakes are in turn the victims of egg-hungry migratory Bristle-thighed Curlews.

The Great-billed Crake is a noisy bird. Its piercing screams are one of the most frequently heard sounds on Sandy Island. The Warburton expedition likened the crake’s vocalization to the tenor saxophone extended techniques of Illinois Jacquet, but more recent accounts have contended that they are much closer to those of Sam Weinberg. All manner of courtship and aggressive displays are exhibited by the Great-billed Crake after the fashion of other crakes, with a great deal of “deep knee bends” that seem to strengthen the pair bond.

It has been posited that Cacroenis inornatus, a mysterious name for a Tuamotu rail used by Bruner in his bizarre book of French Polynesian birds, actually could apply to the Great-billed Crake. The genus name could be loosely translated as “crab-dove”, and it is certainly possible that Bruner wound up on Sandy Island thinking it was part of the Tuamotu archipelago, as many land features on Sandy are very similar to those on some of the Tuamotu islands. The kind of storm described at the beginning of The Cruise Of The Kawa would lead to this level of South Pacific confusion.