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| The new storm-petrel will need to be fully described and compared to exisitng specimens before its identity is fully confirmed. Photo: Peter Harrison ©Lynx Seabirds Handbook Project. |
A new species of storm-petrel has been claimed in Chile, after an expedition obtained photographs of a previously unidentified form at sea.
The discovery follows recent sightings of unidentified storm-petrels in Seno Reloncavi, immediately south of Puerto Montt, Chile, which were the subject of a recent note in Dutch Birding (O’Keefe et al 2010).
Following permissions from Servicio Agricola Y Ganaderro (SAG), a five-person team of biologists, led by British seabird expert Peter Harrison, have just completed a 10-day expedition to the area. The expedition followed Harrison’s earlier examination of two skins of an Oceanites species in the Museo Argentino de Ciencias Naturales, Buenos Aires, Argentina. These were described as the first Argentinian records of Elliot’s Storm-petrel but Harrison, on examining the specimens, concluded that the two specimens represented a hitherto undescribed taxon of Oceanites, and were probably the mysterious unidentified storm-petrels of Puerto Montt, which is just 70 km west of El Bolson. The two re-identified specimens were originally collected at El Bolson, Rio Negro province in Argentina in February 1972 and November 1983.
Harrison enlisted the knowledge and expertise of Chilean ornithologist Dr. Michel Sallaberry Ayerza of the University of Chile, as well as Chris Gaskin and Karen Baird of New Zealand, who were both involved in at-sea captures and searches for the breeding location of the recently rediscovered New Zealand Storm-Petrel. The expedition spent four days at sea in the Seno Reloncavi area, where they made use of 'chummed' to attract seabirds within range of specially-designed net guns, developed in New Zealand for the capture of the New Zealand Storm-Petrel.
Over 1500 sightings of the potential new Oceanites species were recorded. To assist with the scientific description of the new species, 12 birds were captured for biometric data and samples of blood and feathers for genetic work.
The potential new species would appear to be most closely related to Elliot’s storm petrel, but is intermediate in appearance between Wilson’s and New Zealand Storm-Petrel. It shows a distinctive pale upper wing-crescent and a prominent white bar across the underwing coverts. Unlike typical Elliot’s Storm-Petrel, the white feathering in the ventral area is much more subdued and restricted and does not extend towards the upper breast. The wing measurements are also very different and show no overlap with mainland Elliot’s.
The five-person expedition team estimate a population of at least 10,000 birds in the Seno Reloncavi area, where the new taxon appears to be the most abundant of the resident seabirds, with flocks at chum slicks of several hundred individuals. The timing of the expedition also appears to have coincided with the fledging period, as juveniles have been among the captured birds; this suggests breeding occurs in Seno Reloncavi area, possibly beginning in November.
A wider search of the Seno Reloncavi and Golfo de Ancud area needs to be undertaken in both summer and winter. Further analysis on feather and blood samples is expected to confirm this discovery and a full scientific publication with detailed biometric, behavioural and morphological data is in preparation by the expedition team.
http://www.birdwatch.co.uk/channel/newsitem.asp?c=11&cate=__10462
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