Anser anser – GWYDD WYLLT – naturalised resident
Comparison with previous atlas:
|No of tetrads occupied||0||5 (of 490)|
|Percentage of tetrads||1%|
Greylags have been a regular winter visitors to the county since 1972, and are thought to be derived from feral populations. Today, the Greylag Goose is a naturalised resident in Pembrokeshire throughout the year, and breeding was confirmed during the 2003-07 survey.
As shown on the tetrad map, all the records were obtained in tetrads in the vicinity of the Eastern Cleddau, Slebech/Canaston area, or between the Eastern Cleddau and the Carmarthenshire border. It seems likely that the small breeding population that is becoming established in this part of Pembrokeshire is derived from a feral population that was originally introduced by wildfowlers in the Kidwelly area, Carmarthenshire.
The breeding population is small, and is not thought to more than 3-6 pairs. Greylag Geese are, however, opportunistic colonisers, utilising farm reservoirs and large ponds with islands as nest sites, with grazing close-by. Limiting factors on future range expansion are likely to include availability of suitable nest sites, an ultimately finite resource over which Greylag Geese could conceivably come into competition with a rapidly expanding Canada Goose population.