The roost is the largest in two decades.
Shortly after 4pm on Sunday, the first flocks came in low over the headland, dark smudges against a pale sky. By 4.25, they had become a single shape the size of a football pitch, folding and stretching above the old pier at Calder before pouring down into the iron latticework beneath the boardwalk in a roar of wings. Volunteers counting from the promenade estimated the roost at between 92,000 and 110,000 birds.
That makes it the largest starling roost recorded at the pier in more than twenty years, according to the Calder Bird Group, which has carried out counts at the site since the late 1980s. Numbers peaked at around 120,000 in the early 2000s before falling sharply; for much of the last decade, the roost rarely exceeded 30,000 birds, and in two winters it barely formed at all.
Why the birds are back
Scientists say there is no single explanation. Starling numbers across the region fell steeply between the 1970s and the 2010s, largely because of changes in farming, including the loss of permanent pasture where the birds feed on insect larvae in the soil. Some of the recovery may reflect a run of mild winters and wetter summers, which have boosted invertebrate numbers. Dr Isla Carrow, an ecologist at the University of Calder who has studied the pier roost for eight years, said there was also a more local factor.
“Three years ago, the council stopped mowing the grass on the headland and the cliff-top park in spring and early summer, and several farms on the edge of the valley switched to grazing rather than silage. Those fields are now full of leatherjackets and other soil insects. The birds have more food within a short flight of the roost, and you can see the effect in the numbers.”
Ringing studies suggest that many of the birds in the winter roost are not local. Starlings from northern and eastern Europe arrive on the coast in October and November, swelling the resident population. Carrow said tracking data from a handful of tagged birds showed that some had flown more than 1,500 kilometres to reach the headland.
A roost that moves with the pier
The pier itself has played a part in the roost’s fortunes. Starlings choose sites that offer shelter from wind and predators, and the latticework beneath the boardwalk provides both. When a section of the pier was closed for repairs in the late 2010s and covered in scaffolding and netting, the roost moved to a reedbed on the canal for two winters before returning once the netting came down.
The city council’s heritage team, which manages the pier, said it now carried out maintenance work only between April and August to avoid disturbing the birds. Pier manager Colm Deveraux said the starlings had become part of the attraction. “We used to get complaints about the droppings,” he said. “Now we get coach parties.”
That popularity brings its own pressures. On clear evenings at the weekend, several hundred people have been gathering on the promenade to watch the murmuration, and the bird group has asked visitors not to use drones or bright torches and to avoid standing on the pier deck itself after 3.30pm.
How to watch – and how to help count
The roost is expected to remain at the pier until late February, with numbers usually peaking in December. The best views are from the promenade between the bandstand and the lifeboat station, about 45 minutes before sunset. Calm, cold evenings tend to produce the most spectacular displays; on wet and windy days, the birds often come in low and go straight to roost.
The bird group is looking for volunteers to join its fortnightly counts, which use a mix of photographs and block-counting by eye. No experience is needed, and training sessions are being held at the community hall on the seafront on the first Saturday of each month.
Researchers caution against reading too much into a single winter. Starlings remain on the regional list of birds of high conservation concern, and numbers in the hill farms of the western valley are still well below their historic levels. But for those who stood on the promenade on Sunday, as the last stragglers dropped into the dark beneath the pier and the chatter rose to a deafening pitch, the numbers mattered less than the sound.
