Several factors have been proposed, including competition and predation by introduced species, disease, deforestation, and persecution by humans, who hunted it for food and as an alleged crop pest.

The first account thought to mention the hoopoe starling is a 1658 list of birds of Madagascar written by French governor Étienne de Flacourt.

The hoopoe starling was first noted on the Mascarene island of Réunion (then called "Bourbon") by Père Vachet in 1669, and first described in detail by French traveller Sieur Dubois's in 1674:[2] Hoopoes or 'Calandres', having a white tuft on the head, the rest of the plumage white and grey, the bill and the feet like a bird of prey; they are a little larger than the young pigeons.

Some authors also allied the bird with groups such as birds-of-paradise, bee-eaters, cowbirds, Icteridae, and choughs, resulting in its reassignment to other genera with new names, such as Coracia cristata and Pastor upupa.

[4] German ornithologist Hermann Schlegel first proposed in 1857 that the species belonged to the starling family, (Sturnidae), reclassifying it as part of the genus Sturnus, S. capensis.

[2] In 1874, after a detailed analysis of the only known skeleton (held at the Cambridge University Museum of Zoology), British zoologist James Murie agreed that it was a starling.

[8] Some authors proposed a relationship with vangas (Vangidae), but Japanese ornithologist Hiroyuki Morioka rejected this in 1996, after a comparative study of skulls.

[9] In 1875, British ornithologist Alfred Newton attempted to identify a black-and-white bird mentioned in an 18th-century manuscript describing a marooned sailor's stay on the Mascarene island of Rodrigues in 1726–27, hypothesising that it was related to the hoopoe starling.

Günther and Newton found the Rodrigues bird closely related to the hoopoe starling, but kept it in a separate genus owing to "present ornithological practice".

[12] Subfossils found in 1974 confirmed that the Rodrigues bird was a distinct genus of starling; primarily, its stouter bill warrants generic separation from Fregilupus.

[18] Extant relations, such as the Bali myna (Leucopsar rothschildi) and the white-headed starling (Sturnia erythropygia), have similarities in colouration and other features with the extinct Mascarene species.

Except for Madagascar, the Mascarenes were the only islands in the southwestern Indian Ocean with native starlings, probably because of their isolation, varied topography, and vegetation.

A presumed adult male (NHMUK 1889.5.30.15) in the Paris museum has a light ash-grey head and back of the neck (lighter on the hind-neck), with a long crest the same colour with white shafts.

The superciliary stripe, lore, and most of the specimen's underside is white, with a pale rufous wash on the flanks and undertail coverts.

In 1911, Réunion resident Eugène Jacob de Cordemoy recalled his observations of the bird about 50 years before, suggesting that only males had a white crest, but this is thought to be incorrect.

The only illustration of the hoopoe starling now thought to have been made from life was drawn by French artist Paul Philippe Sauguin de Jossigny during the early 1770s.

Jossigny also made the only known life drawing of the now-extinct Newton's parakeet (Psittacula exsul) after a specimen sent to him from Rodrigues to Mauritius, so this is perhaps also where he drew the hoopoe starling.

Murie suggested that only the illustrations by Martinet and Jacques Barraband were "original", since he was unaware of Jossigny's drawing, but noted a crudeness and stiffness in them which made neither appear lifelike.

According to François Levaillant's 1807 account of the bird (which included observations from a Réunion resident) it was abundant, with large flocks inhabiting humid areas and marshes.

[4] Vinson's 1877 account relates his experiences with the bird more than 50 years earlier: Now these daughters of the wood, when they were numerous, flew in flocks and went thus in the rain forests, while deviating little from one another, as good companions or as nymphs taking a bath: they lived on berries, seeds and insects, and the créoles, disgusted by the latter fact, held them for an impure game.

The small Mauritian flying fox and the snail Tropidophora carinata lived on Réunion and Mauritius before vanishing from both islands.

[4]The hoopoe starling was kept as a pet on Réunion and Mauritius, and although the bird was becoming scarcer, some specimens were obtained during the early 19th century.

[24] Several causes for the decline and sudden extinction of the hoopoe starling have been proposed, all connected to the activities of humans on Réunion, who it survived alongside for two centuries.

Like the hoopoe starling, the rats inhabited tree cavities and would have preyed on eggs, juveniles, and nesting birds.

During the mid-19th century the Réunion slit-eared skink (Gongylomorphus borbonicus) became extinct because of predation by the introduced wolf snake (Lycodon aulicum), which may have deprived the bird of a significant food source.

According to British ecologist Anthony S. Cheke, this was the chief cause of the hoopoe starling's extinction; the species had survived for generations despite other threats.

Former slaves joined white peasants in cultivating pristine areas after slavery was abolished in 1848, and the hoopoe starling was pushed to the edges of its former habitat.

According to Hume, over-hunting was the final blow to the species; with forests more accessible, hunting by the rapidly growing human population may have driven the remaining birds to extinction.

During the 1860s, various writers noted that the bird had almost disappeared, but it was probably already extinct by this time; in 1877, Vinson lamented that the last individuals might have been killed by recent forest fires.