Chen caerulescens – Feral visitor
Rare. Three records prior to 2000 when a small feral population established on Skokholm
One on North Plain on the evening of 5th April 2015 was the first since 2010 (HD et al.).
In June 2000 four pinioned birds reached Skokholm, three of the emaciated individuals making it to the plateau where they were fed. The following year two of the birds paired and produced four free-flying offspring. One of the adults and three of the young survived to 2003 and the three young were regularly seen with Canada Geese around the Marloes Peninsula in 2004.
Two birds were seen in 2005, 2006 and 2007, with one pairing with a Canada Goose in the latter year and producing  infertile eggs. A single was logged in 2008, 2009 and 2010, again pairing unsuccessfully with a Canada Goose in the latter two years.
The other Skokholm records are three immatures on 13 June 1971, a Slimbridge ringed bird on 9th May 1975 and five white adults north with four Barnacle Geese on 15th April 1991.
Skokholm Bird Observatory Annual Report 2015 (Richard Brown & Giselle Eagle)