Suffolk Bird Report 2019
Notes on the changing status of Great Black-backed Gull Larus marinus in Suffolk Ed Keeble Introduction Some recent encounters with adult Great Black-backed Gulls in mid-summer on the Stour and Orwell Estuaries prompted me to look into their changing status in Suffolk. I am most definitely not a gull expert, but we are blessed with gull experts in the county and further afield and they have been kind enough to share their knowledge with me. Background and summary In Britain, the Great Black-backed Gull breeds along the coasts of Scotland, Wales and southern England, but despite range extensions in the late-20th century as far south as the Farne Islands, it is absent or very scarce as a breeder along the east coast of Englandi. Consistent with this overall picture, Great Black-backed Gull is mainly a passage migrant and winter visitor to Suffolk, with some oversummering birds, mostly immatures. There has been a substantial increase in numbers reported off the Suffolk coast on passage and in winter. Great Black-backed Gull has bred in Suffolk in small numbers since at least 1999ii. Since then, it has bred at a number of sites, with a maximum annual total of at least 13 pairs in the county in 2014 (this information not being available to section writers in the 2014 SBR). But it has not been a case of initial colonisation, followed by a steady increase in numbers and occupied sites. In recent years breeding has only been recorded at Felixstowe Docks and it is not known how many pairs are currently breeding there. For context, colonisation of Suffolk appears to be well ahead of counties adjacent to us. The first breeding record was as recently as 2013 in Norfolk where at Snettisham one pair, but in 2015 two pairs, nested each year between 2013 and 2018 inclusive, raising a maximum of three young in any one yeariii. So far as I can ascertain, Great Black-backed Gull still has not been confirmed as a breeder in coastal Essexiv. The first breeding record from Greater London was in 2008 and, again so far as I can ascertain, there has not been more than one breeding pair reported in any year since thenv. Passage and wintering in Suffolk Wintering numbers on the Suffolk coast in the latter part of the 20th Century include many three-figure counts including, for example, an annual peak of roosting birds on the Alde-Ore complex ranging between 150 and 500 during the period 1985-1994vi . In recent decades higher counts of between 500 and 1000 have been made including one of 600 on Orfordness on November 30th, 2014vii. Very high counts of birds moving offshore off Gorleston were made during this period including 1709 on November 29th 2016 and a record count for Suffolk off there of c2500 on December 8th 2015viii. Off Landguard, recent high counts include 1000 on November 14th 2019 and 1500 on November 20th 2017ix. It is notable that all of these peak counts have come in late autumn or early winter and so they may relate to local or longer-range movements of the population which winters in the southern North Sea or further south into the English Channel and Bay of Biscay. It is also possible that bad weather may force birds which feed and roost at sea to come inshore- as when 1500 roosted on Minsmere Scrape on January 14th 1987x. It has long been known that a high proportion of Great Black-backed Gulls wintering off the east coast of the British Isles are from Norwayxi and in recent years there have been many readings in Suffolk of colour-ringed birds from Norway. Of 74 colour rings reported by one observer in Suffolk over the period from 2004 to date, 60 were from Norway and 14 from Denmark.xii It has 32
