Seaweed lifeline for shorebirds on the move

Turnstone (Marc Hughes)

​I have spent several mornings recently carefully scanning the flock of Sandwich Terns at Rhos Point, looking for legs that carry engraved colour-rings. With a few other tern-watchers along the North Wales coast, we have recorded more than 250 different birds so far this autumn and since at least 4000 Sandwich Terns are roosting across Liverpool Bay at Formby Point, along with the Elegant Tern that summered at Cemlyn, we may have some busy mornings yet to come. Each day has brought more waders to the seaweed-covered beach, perhaps their first landfall since leaving Svalbard or Iceland after the breeding season. Some will have begun their journey even farther away, such as the Bar-tailed Godwits that may have originated in Siberia or the Turnstones from Greenland or Arctic Canada.

It is always a joy to watch Turnstones, the adult males still in their smart plumage of orange and black. The English name accurately describes their feeding behaviour, turning over pebbles and seaweed in search of invertebrates that sustain them on migration to West Africa or through a European winter. Some Canadian-breeding Turnstones arrive in North Wales via Scandinavia, such as one ringed in Sweden in 1983 that was seen at Rhos Point in three successive winters.

Seaweed is a complex mosaic of microclimates, and the invertebrate food available to shorebirds increases as the wrack decays. Stacks of seaweed also provide shelter and warmth for the birds, providing they are not disturbed by walkers, so the beds along the North Wales coast really can be a life-saver for these birds on their long-distance journeys. To read more about the value of seaweed for waders, have a read of this WaderTales blog.

Other waders in North Wales this week include a Pectoral Sandpiper at RSPB Burton Mere Wetlands, up to four Spotted Redshanks at RSPB Conwy and eight at Connah’s Quay nature reserve, with Whimbrels and Greenshanks scattered along the coast.