Anser anser – GWYDD WYLLT
Greylag geese were rarely recorded in Pembrokeshire prior to 2000 but since 2011-12 they have been seen more regularly. Counts of 100+ birds are now not unusual on the upper parts of the Cleddau Estuary. They are thought to be descendants of a population introduced by wildfowlers to the Kidwelly area in Carmarthenshire.
Distribution

This map was produced by the West Wales Biodiversity Information Centre using data collected between November and February for the BTO Atlas 2007-11, with additional data collected in 2011-12 winter to fill gaps in coverage.
The main sites are:
The main flock of greylags spend their time commuting between the upper parts of the Cleddau Estuary, especially the Langwm-Hook-Eastern Cleddau area, and the surrounding fields where they feed. However, small numbers may be encountered on bodies of water of any size elsewhere.
Wetland Bird Survey

Monthly WeBS totals can be seen here
Pattern of occurrence

Annie Haycock (BBS & WeBS local organiser)
HODGES J E. (2010-2020) Daugleddau Estuary and Milford Haven Waterway: annual surveillance of summer shelduck populations. Reports to the Milford Haven Waterway Environmental Surveillance Group.