East meets West on an Anglesey reservoir

Smew (Martin Jones)

This week’s forecast Arctic blast of weather was prefaced by the appearance in central Anglesey of a duck from the east. A male Smew is on Cefni Reservoir, already providing a winter home to a Ring-necked Duck from North America. Smew visit from northern Scandinavia and Russia, where they nest in large holes, often made by a Black Woodpecker, in mature broad-leaved trees such as oak, willow and aspen.

The fortunes of these two ducks would astonish an ornithologist from a century ago. In recent years, the number of Ring-necked Ducks has increased and it is no longer considered a rarity by the Welsh Ornithological Society. Smew has become much rarer, however, as its winter range has contracted to the north and east, a phenomenon known as ‘short-stopping’. With climate change reducing the frequency of wintering waterbirds such as Bewick’s Swans here, expect fewer Smew to make it to Wales.

Sightings of adult male Smew are unusual – the last in North Wales was back in February 2006. While its English name is probably of Dutch origin, its Welsh name Lleian Wen (white nun) derives from the male’s appearance. Most Smew in Wales are ‘redheads’, a term used to describe females and males in their first winter.

Other waterbirds along our coast include Baikal Teal and Scaup at Foryd, near Caernarfon; Surf Scoters at Llanddulas and Benllech, and Long-tailed Duck and Black-throated Diver at the latter site. Four Slavonian Grebes are on Anglesey’s Inland Sea and another two were reported off Llanfairfechan at the weekend, where more than 120 Great Crested Grebes have gathered before they disperse to inland breeding lakes.

Chiffchaffs and Blackcaps seen recently may have overwintered here, but those showing traces of pollen around the base of the bill have probably arrived from the south, where spring is more advanced. A Swallow at RSPB Cors Ddyga on Sunday is the first of the year reported in North Wales. A Bearded Tit was reported from Gronant last week, the second record in the region in recent weeks.