Increasing visitor and feral resident.

Domesticated Greylag Geese were formerly kept at farms in Stevenage for both food and their “guard dog” qualities. 

In recent years the numbers of Greylag Geese of feral origin have increased in Hertfordshire with quite large flocks seen.

Birds of possible wild origin are occasionally seen at Fairlands Valley Lakes and birds of feral origin are regularly seen. The earliest record from there is from November 1983 and, the 33 seen on 12 November 2025 is the highest number of birds seen together there.

Single birds are also occasionally seen at the Town Centre Gardens, with five seen there on 5 July 2018.

Four were seen flying over Norton Green Tip on 5 April 2016, two were seen feeding among c.200 Canada Geese (Branta canadensis) at Astonbury Farm on 16 November 2022, two were seen flying over Astonbury Wood on 31 March 2024 and, one flying over Astonbury Wood on 4 May 2024.