GREAT BLACK BACKED GULL (Larus marinus)

Uncommon visitor.

According to Foster (1914) they had, “occasionally occurred in North Hertfordshire, but were not common” 

The records for the 1960s and 1970s are: Single birds over Box Wood on 1 January and 28 August 1965; 20 over Stevenage on 15 March 1968; six over the Old Town, mobbing a Buzzard (Buteo buteo) on 21 May 1968; seen over Monks Wood/Whomerley Wood 1969; one over Fairlands Valley on 2 August 1970; one at the Industrial Area on 10 January 1973; one at Fairlands Valley on 22 January and 18 February 1979.

One record from the 1980s with three at Fairlands Valley Lakes on 18 January 1980.

No known further records until 2016 when one was seen at Norton Green Tip on 8 September. The records since are: one at Fairlands Valley Lakes on 19 January 2020; an adult at Fairlands Valley Lakes on 11 October 2021; one at Fairlands Valley Lakes on 15 December 2022; one at Fairlands Valley Lakes on 6, 19 and 28 January 2023. 

The 2012 Winter Atlas confirmed their presence from the tetrad covering Boxbury Farm.