I take it all back: have a look at Mark’s very helpful comment here, which shows clearly that “haesitata” is the correct reading and that it means “doubtful.”

In his splendid new photographic guide to the North American tubenoses, Steve Howell laments the nomenclatural and taxonomic “clusters” that hound so many of these birds. He’s absolutely right: it’s a mess, as even the quickest glance (and who could stand more?) at Coues’s bibliographical notes on the history of tubenoses will prove.

Take, for example, the beautiful and rarish Black-capped Petrel. The AOU Check-list tells us merely that this bird was named Procellaria hasitata by Heinrich Kuhl in 1820. But a look at that original description suggests complication. Kuhl attributes the discovery of the species to the great Johann Reinhold Forster, who, says Kuhl, depicted it on two of his plates, once as Procellaria hasitata and once under the name leucocephala.

But Forster’s ornithological records were still unpublished in 1820 (they would not appear in print until 1844, nearly 50 years after Forster’s death), so Kuhl gets the credit for naming the species. It turns out, however, that Kuhl somehow got his petrels mixed up, and that Forster’s name hasitata actually referred to the Gray Petrel, nowadays known (rather prosaically) as Procellaria cinerea. Thanks to the rules of publication and priority, though, Kuhl’s name is the one that stuck.

But what about this name hasitata? There’s no such Latin word, and the emendation to haesitata–made by many, including Coues himself, without comment–isn’t much of an improvement. Instead, I suspect that Kuhl followed Forster in a different misspelling.

The perfectly good Latin word “hasta” means spear or blade; “hastatum,” which comes into botanical English as “hastate,” means “bladelike,” sharply pointed or angular. In ornithology, the adjective is used to describe the shape of the angular spots on the Indian Spotted Eagle and on the southwest Mexican subspecies of the Middle American Screech-Owl. I think that Forster used the word, with the insertion of a barbarous -i-, to indicate the sharp, bladelike wing shape of his bird, which he thus named “bladelike stormbird.” Evocative, isn’t it? And maybe even plausible.

How much easier it would all have been had Lafresnaye got there first! In 1844, working from a manuscript by L’Herminier (who–small world–provides the eponym for the Audubon’s Shearwater) and echoing the Creole name “diablotin,” the French naturalist renamed the species Procellaria diabolica, a fitting name for a bird whose taxonomic history is so devilish.