An adult Red-breasted Goose Branta ruficollis was present on the North Slob, Wexford from 26th October 1997 to16th March 1998 representing, potentially, the first record of this species in the wild in Ireland.
Assessment of the identification posed no difficulty with photographs and descriptions clearly showing that it was an adult Red-breasted Goose, but, from the outset, there was much speculation as to the likelihood of it being accepted into Category A of the Irish list. Claims of vagrant wildfowl, particularly geese, are notoriously difficult to assess given the difficulty in determining whether a bird is a genuine wild vagrant or of captive origin. This difficulty was well illustrated, for example, with the appearance of a Hooded Merganser Mergus cucullatus in Kerry in 1996/97. This bird occurred at the 'right' time of year in the 'right' part of the country but which ultimately proved to be colour-ringed in a manner untypical of North American ringing techniques, casting serious doubts on its origin.
In the course of assessing the Red-breasted Goose record, various European Rarities Committees were contacted. Information was requested relating to:
- Details of extralimital records in Europe during the winters of 1997/98, 1998/99 and 1999/2000.
- The criteria used to determine the most likely origin of birds recorded outside their normal range.
- The pattern of occurrence of those birds deemed to be vagrants.
Helpful replies were obtained from the British (Colin Bradshaw), Belgian (Peter Adriaens, Gunter de Smet) and Danish Rarities Committees (Kasper Thorup). The general rule on the continent of Europe tends to be that a Red-breasted Goose occurring in a flock of wild geese (nearly all of which come from Russia) is assumed to be of wild origin, while those appearing out of this context (lone individuals, unseasonal birds or those at odd localities) are assumed to be of dubious origin. In Belgium, the arrival of Red-breasted Goose normally coincides with the first frost, typically at the end of December, but sometimes as early as the beginning of November. Genuine October records are very rare. Records outside the period 29th October to 7th March are treated with extreme caution. The longest stayers usually have left by the end of February. Unlike in the Netherlands, where they often turn up with Barnacle Geese Branta leucopsis, in Belgium they are invariably found among Russian White-fronted Geese Anser albifrons albifrons (undoubtedly due to lack of Barnacle Geese). Birds arriving/staying on their own are almost invariably treated as escapes. In Denmark, the most typical pattern of occurrence is of birds (sometimes family groups) in flocks of Barnacle Geese. Migrating birds are seen in April and September/October in east Denmark and birds arrive in October to winter with Barnacle Geese in the Wadden Sea, (the coastal section between Den Helder, Netherlands and Esbjerg, Denmark) leaving this area from March to mid-May. From 1999 onwards, Red-breasted Goose is no longer considered by the Danish Rarities Committee.
More often than not, vagrant geese seem to arrive as a result of having become attached to a flock of other geese (usually congeneric) with which they overlap in their breeding ranges or on their migration routes. In the case of Red-breasted Goose, likely carrier species are Dark-bellied Brent Goose Branta bernicla bernicla, Russian White-fronted Goose and the Novaya Zemyla population of Barnacle Goose. However, Pale bellied Brent Goose B. b. hrota, Greenland White-fronted Goose A. a. flavirostris and the Greenland population of Barnacle Goose, the main taxa of wild geese recorded in Ireland, are not likely to meet genuine Red-breasted Geese on migration. According to Scott and Rose (1996) there is normally no exchange between any geese wintering in Ireland and geese wintering on the continent. In this respect it would be surprising that a solitary Red-breasted Goose would cross the gap between the different wintering populations. Considering that very few nominate albifrons reach Ireland, in spite of the huge wintering population elsewhere in Europe, it would be much more unlikely for a Red-breasted Goose to do so.
In addition, a limited amount of information on the captive status of Red-breasted Goose in Ireland was obtained. The species is relatively widespread and numerous in captivity in the UK and in mainland Europe. There are several collections of exotic wildfowl throughout Ireland and there is a considerable number and variety of species imported as well as bred in captivity (Neil Stronach, Director, Fota Wildlife Park, pers comm.). In Wexford alone, two birds were known to be present in a collection close to The Cull, some 25 kilometres from the North Slob. These birds were unringed and unpinioned and indeed one went missing from the collection in 1998. While this individual clearly was not the same as that on the North Slob, it is a dramatic illustration of the escape potential of this species in Ireland. Other Red-breasted Geese are known to be in private collections in Co. Kilkenny (along with many other species, including American Wigeon Anas americana, Baikal Teal Anas formosa, Garganey Anas querquedula and Ross's Goose Anser rossii ) and in Co. Cork. Even more damning is the fact that Red-breasted Goose has been offered for sale in Ireland through Buy and Sell Magazine.
Interestingly, the BBRC has recently (Brit. Birds 95: 263) decided to examine the patterns of occurrence and provenance of wildfowl in Britain in detail, starting with the geese, in an effort to aid discrimination between escaped and vagrant individuals.
The application of very rigorous criteria in assessments such as this is probably open to debate. Furthermore, against the evidence suggesting a captive origin, it is noted that 1997 was a record year in Sweden and Germany for Red-breasted Goose. The possibility of the North Slob individual crossing over from a flock of European/Russian Barnacles to a flock of Greenland White-fronted Geese in Scotland cannot be discounted, but, without any firm circumstantial evidence for this, it is very difficult to factor such an event into the equation.
In conclusion, with very small numbers of potential carrier species of Russian/Baltic origin arriving in Ireland each year, combined with the early arrival and late departure dates, the likelihood of this individual being of wild origin is considered doubtful. On that basis, a decision has been taken to accept it into Category D of the Irish List.
Decisions such as this are not easily taken by the IRBC. Research on this specific claim has been actively ongoing over the past four years and the correspondence on the file runs to many pages. While there is pressure from the birding community to accept this record as a Category A addition to the Irish List, it should be reiterated once again that the role of the IRBC is to maintain the Irish List and for a first Irish record, we believe that a bird should have stronger, water-tight credentials. However, it is the sole prerogative of individual birdwatchers as to whether or not to include them on personal lists.
Scott, D.A. & Rose, P.M. 1996. Atlas of Anatidae Populations in Africa and Western Eurasia. Wetlands International Publication 41.