Proposal (737) to South American Classification Committee
Add Murphy’s Petrel (Pterodroma ultima) to the South American list
Flood et al. (2016) reported three different sightings of Murphy’s Petrels near the Juan Fernandez Islands, in Chile, in November 2014. The publication includes three black-and-white photos of individuals on two different days. All observations are detailed with GPS coordinates; all were within 31 km from land, so all are clearly in South American waters.
Given the good quality of the photographs, the identification is rather straightforward. The only dark Pterodroma found on Juan Fernandez is the rather different looking Kermadec Petrel (Pterodroma neglecta), which shows a stronger pale primary patch, pale supraloral area, and a much thicker set, and short-tailed structure. The Murphy’s Petrels photographed by Flood et al. (2016) show small billed and small-headed birds, with a stocky structure yet long tapering body behind the wings, and longish wedge-shaped tail. A short-winged structure for Pterodroma, and noticeable but dull pale panels on base of under primaries and under primary coverts. There is a pale throat patch and a slight extension of this over the bill.
The features noted are diagnostic. Two similar species are the Providence Petrel (Pterodroma solandri) and Great-winged Petrel (Pterodroma macroptera), but both are stockier, bull-necked, and thicker in the chest with shorter tails, particularly so on the Great-winged. Both are more extensively white on the face and are much thicker-billed. Providence Petrel also shows a very distinct and obvious set of white areas on underside of primaries and primary coverts, much more distinct than what a Murphy’s would show. Quite opposite to this, the underwings of Great-winged Petrel are nearly uniform, without pale patches. The rare Henderson Petrel (Pterodroma atrata) is very long-winged, slim, and it shows a distinctive white patagial stripe. This may be a cursory run through some of the more likely dark Pterodroma in the south Pacific. But key is that the photos published are diagnostic for Murphy’s based not only on plumage, but also importantly on bill size and overall structure.
Other sightings of Murphy’s Petrels in South American waters are detailed in the paper, although no information on photo, or other documentation is given for these records. They include a sighting in the Humboldt Current off Peru. It is possible that Murphy’s ventures to the outer edge of the Humboldt, in the same manner as they do in offshore waters of the western United States. The closest breeding areas are on Easter Island, and Sala y Gomez islands farther west in Chile, but these are outside the SACC checklist area. As such, these observations of Murphy’s on the Juan Fernandez are not altogether surprising, and likely they are a regular albeit uncommon component of the avifauna there.
I recommend a YES vote to add this species to the South American Checklist.
Flood, R. L., A. C. Wilson, M. Danzenbaker, J. Ryan, J. Shemilt & K. Zufelt. 2016. Three Murphy’s Petrels Pterodroma ultima off the Juan Fernandez Islands, Chile, November 2014. Cotinga 38: 110-112.
Alvaro Jaramillo, January 2017
Comments from Remsen: “YES. Published photograph leaves no doubt on identification.”
Comments from Stiles: “YES. While presenting the photographs in the proposal would have been nice, I will accept expert opinions here, which are also consistent with the illustrations I checked in Harrison’s book on seabirds.”
Comments from Areta: “YES. Photos can be confidently identified as P. ultima.”
Comments from Pacheco: “YES. Alvaro's analysis is persuasive in this decision.”
Comments from Robbins: "Yes, for adding Pterodroma ultima to the list based on the diagnostic photos."