The Mascarene Petrel is rarely seen, little known and critically endangered. Our paper on the species has now been published in the Bulletin of the British Ornithologists’ Club (Bull. B. O. C.). It is extensive and lengthy - 30 pages, 36 colour photographs/figures, four tables plus two colour plates from the forthcoming tubenoses monograph - and deals with identification, confusion species, breeding, amongst the many headings. The summary can be found below.
The paper has the first photographs of Mascarene Petrel at sea, and one particular photograph is remarkable as it shows a large egg being carried in the body by one bird; this likely to be the first published photograph of any land- or seabird in flight showing the obvious bulge of an egg in the uterus.
Mascarene Petrel is difficult to identify, especially when comparing nominate Great-winged Petrel Pterodroma (m.) macroptera (and both are found in the Indian Ocean). To illustrate this, the link http://www.seabirding.co.uk/MascarenePetrel.htm has one of the figures from the paper showing the similarity between these two species. You can also view one of the portrait photos of Mascarene Petrel on that same web page.
Shirihai, H., Pym, T., San Román, M. & Bretagnolle, V. 2014. The Critically Endangered Mascarene Petrel Pseudobulweria aterrima: identification and behaviour at sea, historical discovery of breeding sites, and breeding ecology on Réunion, Indian Ocean. Bull. Brit. Orn. Cl. 134: 194-223.
The paper is available for purchase from The British Ornithologists’ Club: www.boc-online.org (under The Bulletin).
The Critically Endangered Mascarene Petrel Pseudobulweria aterrima:
identification and behaviour at sea, historical discovery of breeding sites, and
breeding ecology on Réunion, Indian Ocean
by Hadoram Shirihai, Tony Pym, María San Román & Vincent Bretagnolle
SUMMARY.—Results from pelagic expeditions to study Mascarene Petrel Pseudobulweria aterrima off Réunion, Indian Ocean, in December 2012, are presented. At-sea identification features, flight characters and feeding behaviour are described, as well as comparisons with confusion taxa. Adult plumage, the least known, is described in detail. Photographs, believed to be the first of this species taken at sea, are presented. One shows a female with an egg inside her body, providing evidence of return from pre-laying exodus and adding to understanding of the breeding cycle. Thirty-three individuals were recorded during three days at sea. Nine presumed breeding burrows, at six different sites, were found on Réunion in 1997–99 and the background to this significant discovery is included, together with an updated population estimate for this elusive species.
Tony Pym, Hadoram Shirihai, Vincent Bretagnolle