Heinroth's Shearwater Puffinus heinrothi Scientific name definitions

A very poorly known seabird whose breeding grounds are still yet to be definitely discovered, Heinroth’s Shearwater is found in the Bismarck and Solomon Seas, where it is presumed to nest on Bougainville, Kolombangara and Rendova (in the Solomon Islands); historic data suggest that it also bred on New Britain in the Bismarck Archipelago. A small, slender, relatively long-billed, long-tailed and mostly dark shearwater, it has been suggested that observed plumage variation indicates that the species is polymorphic—dark (c. 60% of recent observations off New Georgia), intermediate (c. 30%) and pale (c. 10%)—although some birds have plumage that apparently cannot be categorized, and it is also the case that the presence of a substantial number of so-called intermediates also raises questions as to whether the variation can be truly considered representative of morphs. Recent observations suggest that Heinroth’s Shearwater regularly consorts with the similarly sized Black Noddy Anous minutus attending prey forced to the surface by schools of tuna, in flocks of up to 100 birds, but it also feeds alone. The population has been most recently estimated at just 250–999 mature individuals, and is considered Vulnerable under IUCN criteria for evaluating conservation status.