Cygnus olor – Alarch Dof – Breeding resident
|No of tetrads occupied||11 (of 478)|
|Percentage of tetrads||2.3%|
Mathew (1894) stated that they were originally introduced and noted Bosherston Pools as “their chief station” and that up to about 100 could be seen there in the summer, with many pairs breeding. Only eight to ten remained in the winter, when a few moved to the Cleddau Estuary but the majority appeared to have left the county. This situation continued into the 1920s and 1930s according to Mr Barnaby, the son of Earl Cawdor’s agent, (per R.J. Haycock) but only one or two pairs breed there now and three to five is a typical winter population. Lockley et al. (1949) and Saunders (1976) noted several breeding sites along the saltings of the Cleddau, Nevem and Teifi estuaries but these a re no longer used, the ten pairs that breed annually all being at freshwater sites.
There are normally about 30 birds on the Teifi Estuary in winter, and this is presumably the source of the Mute Swans that occasionally visit the Nevem Estuary, and more rarely Fishguard Harbour. Up to 50 winter on the Cleddau Estuary, mainly at Llanstadwell and the Pembroke River, the non-breeders staying throughout the year. Mute Swans have been recorded twice from both Skokholm and Skomer.
They are vulnerable to oil spills and 16 had to be removed for decontamination following the ‘El Omar’ incident in the Cleddau Estuary during December 1988. Four died but the rest were rehabilitated the following spring.