Changes in the abundance and distribution of upland breeding birds in the Berwyn Special Protection Area, North Wales 1983-2002

Abstract

The Berwyn Special Area for Conservation (SAC) is the most extensive blanket bog and upland heath in Wales.  The site was also designated in 1998 as a Special Protection Area (SPA) for its internationally significant numbers of Hen Harrier Circus cyaneus, Merlin Falco columbarius, Peregrine Falco peregrinus and Red Kite Milvus milvus. Following the Second World War, moorland management for Red Grouse Lagopus lagopus scoticus declined and by the late 1990s driven grouse shooting had ceased. Numbers of Red Grouse shot peaked in the early 1900s, but declined thereafter. Red Grouse densities between 1995 and 2010 varied between moors, but not between years or through time.  Between initial surveys in 1983-5 and a further survey in 2002, Lapwing Vanellus vanellus were lost, Golden Plover Pluvialis apricaria declined by 90% and Curlew Numenius arquata by 79%.  In contrast, increases were seen in Carrion Crow Corvus corone (529%), Raven Corvus corax (308%), Buzzard Buteo buteo (150%) and Peregrine (700%). Numbers of Hen Harriers declined by 49%. There were no significant changes in Merlin and Red Kite.  Meadow Pipits Anthus pratensis increased (103%), as did Whinchat Saxicola rubetra (123%) and Stonechat Saxicola torquata (986%). Ring Ouzel Turdus torquatus declined by 80%.  Changes in distribution were observed in Red Grouse and Curlew, occupying 40% and 57% fewer study plots in 2002.  Study plots occupied by Stonechat increased by 333%.  Raven occupancy increased (140%), as did Buzzard (63%) and Peregrine (500%). To restore numbers of key species of ground-nesting birds, we recommend a repeat survey of ground nesting birds in the Berwyn SPA, and targeted moorland management which includes habitat enhancements and the control of generalist predators.