A shearwater washed up on the beach at Tramore Bay, Co. Waterford on Monday is about to add to the recent run of stunning seabirds this summer. The bird was in an extremely poor state when found during Mondays gale and unfortunately, it has subsequently died while in a rehabilitation centre. At the time, it was recovered by Arlo Jacques and Adrian Allen and rested overnight. Initially, it was expected to be a Manx, but as it dried out and the true colour and pattern of the underparts became obvious, the ID turned towards it being a Mediterranean Shearwater.
Before being sent on to the experienced rehab facility some key measurements were taken. The bird was in moult and missing 3 inner primaries, making very accurate measurements of wing length quite difficult to assess but they exceed and thus rule out any variant of Manx, including Balearic (Mediterranean) Shearwater while falling well short for Sooty Shearwater. Critically, though the bill measurements are just at the maximum known range, a careful assessment of this character provides adequate evidence that this is in fact a SHORT-TAILED SHEARWATER (ardenna tenuirostris). Some photos of the bird alive (by Adrian Allen) and post mortem (PA) are at https://drive.google.com/drive/folders/120ErxuBNnVdVl474f-q-RaPTQ9Kg9FZc
Unfortunately due to the birds very poor condition when found rehabilitation attempts were unsuccessful and, not unexpectedly, it didn’t survive. Resuscitation and rehab of such seabirds is very difficult and has a very low success rate. The corpse will undergo a necropsy to determine age, sex and potential cause of death and then be provided to the Natural History Museum. Feathers samples have been taken and will be sent for DNA analysis, the results of which will be provided when available.
Short-tailed breeds in Australia and Tasmania and winters at sea in the cooler regions of the North Pacific between Alaska and Hawai’i. It has been mooted as a potential vagrant but separation at sea (from Sooty and Balearic Shearwater) is very difficult. There has been a number of recent records from the Eastern seaboard of the US and recent research suggests that it is regular in the higher latitudes of the southern Atlantic so it seems likely that more will be found. A paper by Bob Flood and Ashley Fisher in BB in May 2019 drew attention to the possibility of identifying Short tailed Shearwater in European waters and has proved truly timely.
Credit is due to Arlo and Adrian for persistence in awful weather to rescue this bird without which action there would be no story. Thanks to Killian Mullarney who was alert to the possibilities and encouraged scrutiny when it was needed and to Bob Flood for research, guidance and advice on the ID.